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It is difficult to construct an electric guitar without reaching for the router. Control and pickup cavities, neck pockets and tremolo recesses are all operations that require the use of this versatile tool, and all of these examples are made much easier and safer by the use of a template and an inverted pattern bit to guide the router around the intended cut. One routing pattern that can be difficult to execute accurately is for a Floyd Rose Original tremolo, particularly the recessed version whereby the arm can be raised or lowered above and below its equilibrium point. The following article describes a system that lends itself well to performing this difficult routing operation by the use of a master indexing plate on to which a number of different templates can be attached to create the complex routing pattern. The system can be adapted for other patterns as well such as pickup cavities or other tremolo systems. The System Referring to the PDF plans attached to the bottom of this post, the Floyd Rose routing templates are based around a master indexing plate (Sheet 1). The centre of the plate has a 120mm x 100mm window which can accept a matching template insert. Near the perimeter of the plate are mounting holes for installing further templates which may be overlaid on top of the indexer to provide extra tool height for shallow cutting operations which would otherwise cause the router bearing to ride higher than the template. The templates used in this example have been created from clear Perspex, but MDF can also be used. Perspex however has the advantage that it is possible to see through the template to help position it against reference guidelines drawn on the body to ensure perfect alignment. Sheet 2 shows the insert that is installed within the window of the indexer and contains the guides for drilling the tremolo post holes and the penetration for the trem sustain block. Sheet 3 details the overlay template that is attached on top of the indexer for routing the cavity for the bridge plate of the Floyd Rose. With the end stop shown on Sheet 4 fitted to the overlay template, the extra depth required for the fine tuners at the rear of the bridge can also be routed. Sheet 5 describes the template for routing the rear of the body for installing the springs. Constructing the templates Begin with the indexer. After cutting the perimeter of the plate mark the centreline and intonation reference lines as shown on the diagram as squarely as possible. If using Perspex scribe these lines on the underside of the template. Having these lines under the template assists with lining up the location of the template on the guitar body. The window cut-out in the index plate can be created using a coping saw to rough out the cut, followed by a router guided by temporary fences to ensure straight, square edges. Note that the indexer can be as large as you like, so long as it remains easy to attach to your guitar. Cut and shape the outline of the insert plate and check the fit in the indexer window. The insert plate needs to be a snug fit with no slop while remaining easily removable. With the insert fitted to the indexer mark the cut-outs and drill locations detailed on sheet 2. Performing the marking of the insert while fitted to the indexer ensures the locations of the cut-outs remain square and true relative to the centreline scribed on the indexer. Remove the insert and complete the cut-outs as carefully as possible. Move on to the overlay template. Again, use the centreline on the indexer as a reference to aid in aligning the two when marking the locations of the cut-outs in the overlay template. With the templates constructed as shown in the plans the front edge of the overlay needs to be on the same alignment as the front edge of the indexer. If you chose to make the indexer wider ensure that you maintain the same horizontal positioning of the overlay template so that the resultant rout is at the correct location. The four 4mm holes should be drilled while the two pates are clamped together so that they remain in perfect alignment. These holes are used to lock the two plates together while routing. Removable pins or screws should be installed to align together them when routing provided that they do not protrude, and either damage the surface of the guitar body or hinder the movement of the router. The removable end stop can be constructed using two strips of material laminated together to make the required step profile. Two screw holes should be bored through the overlay template into the end stop to allow the two components to be secured together when performing the routing operation. The final template, the spring cavity rout can be created separately to the indexer. Mark or scribe the dashed line shown on the drawing as perpendicular as possible to the centreline. Tools required for using the templates Plunge router with adjustable depth stop Drill press with adjustable depth stop 1/2" diameter inverted pattern router bit with bearing, length 19mm 1/2" diameter inverted pattern router bit with bearing, length 32mm 3/8" diameter inverted pattern router bit with bearing, length 19mm 10mm brad point drill bit Optional - Forstner bits for removing excess timber prior to routing Clamps Using the templates 1. At this stage you should have a guitar body ready to be routed to accept the Floyd Rose bridge. A centreline should be marked on the body along with an intonation reference line drawn at right angles across the full width of the body at your chosen scale length. In the following example a scrap piece of pine has been used to rout the bridge cavity. No intonation line has been marked, but your actual build will require this to ensure the Floyd Rose is installed at the correct distance from the nut. 2. Align the index plate with the centreline and intonation reference line drawn on the body and clamp it securely. Test-manoeuvre your router around the indexer to ensure your clamps do not interfere at the extremities of the window in the plate and adjust if required. Alternatively you can use double-sided stick tape provided it is of good quality and doesn't allow too much lateral movement of the templates once adhered. Fit the insert plate into the window and using the two 10mm template holes as a guide bore the trem post holes using a 10mm brad point bit to a depth of 10mm or so. The exact depth at this stage isn't critical. Were just establishing the location of the post holes to start with. 3. A Forstner bit can be used to remove some of the waste within the 24mm x 76mm cut-out of the insert template to a depth of approx. 25mm to minimise wear on the router bit. Using the 1/2 diameter, 32mm long inverted pattern bit rout this template to a depth of 29mm. 4. The insert plate can now be removed from the indexer and the overlay plate installed over the top. Again, use the Forstner bit to remove some of the waste to a depth of 5mm. Use the 3/8 diameter, 19mm long inverted pattern bit and rout the whole area to a depth of 6mm. 5. Creating the rear well that allows the bridge to be pulled backwards when raising the trem arm requires routing a secondary depth at the back of the cavity of an additional 6mm. This is achieved by fitting the small stop bar to the overlay template that reduces the router lateral travel by 16mm. Run the router within the template to a depth of 12mm below the face of the guitar body. 6. The indexer and templates can now be removed from the body. Using a drill press bore all the way through the body down through the bottom of the sustain block rout. The exact location and size of this hole isn't critical, just as long as it is as close to the front edge of the rout as possible. Where the drill exits the body at the rear, mark a line perpendicular to the centre of the body that touches the tangent of this drill hole. This line should now align with the front edge of the sustain block rout and is used for locating the final template for routing the spring cavity. 7. Fit and clamp the fourth template, aligning it with the centre and sustain bock reference lines on the back of the body. Assuming your body is a typical Strat thickness (45mm or so), rout this template to a depth of 16mm using the 1/2 diameter 19mm long inverted pattern bit. If your body is a different thickness this will change how deep this rout must be. The rout needs to be deep enough to allow clearance for the springs and sustain block, but not so deep that you risk punching through the underside of the pickup routs. Ideally this depth should be [thickness of body] - 29mm. 8. An additional depth to the rear edge of the spring cavity is required to allow clearance for the sustain block to swing backwards when the trem arm is depressed. This depth is again dependent on the thickness of your body but should be [thickness of body] - 15mm. For a typical Strat this will result in a cutting depth of 30mm. The resultant rout will leave a small 3mm ledge of timber that is visible when viewing back through the sustain block cavity. Use the 1/2 diameter, 32mm long inverted pattern bit to complete this cut. Take care not to run the bit into the forward edge of the sustain block rout. A temporary fence may be clamped to the work piece to prevent the router being accidentally moved into the front wall of the sustain block rout. 9. The last step is to bore the final depth of the trem bushing holes. Remove the last template and flip the body over. Measure the length of your trem bushings and set your drill press depth stop to this value. Using a 10mm brad point bit on the drill press bore down the two 10mm holes that were established in step 2. Once the holes have been drilled the bushings can be pressed into the guitar. They should go in with firm hand pressure. An alternate method is to use a drill press with a short piece of dowel in the chuck to press the bushings in. Be careful when applying pressure however, as the small amount of supporting wood behind the bushing holes is fragile and can be easily split if the bushings require excessive force to be pressed in. 10. Test fit the bridge and check to see if there is sufficient clearance to allow the bridge to swing up and down without binding on any of the routs. Adapting the system Because the routing templates can be removed from the master indexer the user has the ability to create other template inserts and overlays for different routing tasks. Any shape that can fit within the dimensions of the 120mm x 100mm window has the potential to be made into a template for repetitive or complex routing operations. Pickup cavities, battery box cavities, Kahler and Wilkinson tremolos are some examples. ------ DOWNLOADABLE TEMPLATE SHEET FILES FR Routing Templates.pdf
Laser cutting takes what we engineer at the desktop and brings it out into the real world. For a luthier, this enables creating our most common working tools - router templates - to be made simply yet precisely. A real game changer! Translating creative or technical design work into router templates opens up a world of design options. Anything from an accurate outline of your body/headstock, pickup and electronics cavities, through to complete modular templating systems for recessed tremolos, etc. Powerful desktop design tools and laser cutting takes your building to the next creative and technical level. "Having it laser cut" sounds like a magic bullet of sorts; draw something up and having it drop out of the other side with little to no real effort. That's not actually too far from the truth; the technology is definitely more usable and accessible than it ever had been. The key to winning lies in mastering a number of simple fundamentals and managing a few basic expectations. Once you've moved beyond these, laser cutting becomes a very workable part of your armoury and one that you'll always find new ideas and challenges for....and like any tool, it is only as good as what you make of it! ----==---- ARTICLE SCOPE - The focus of this article will be on how to locate and choose the right laser-cutting service, illustrate the desktop work necessary to produce drawing files that are pretty much good to cut and finally show a couple of real-world working examples. We are making a few assumptions here. First is that you know basic vector work (AutoCAD or other CAD packages, Illustrator, Inkscape, CorelDRAW, etc). Secondly, that you are more or less familiar with manipulating vectors, managing object types, inspecting and changing their attributes, etc. with your chosen vector drawing package. Beyond this, laser cutting is a pushover! ----==---- CONTENTS - 1. Finding Your Laser 2. Starting Out - Communication Is Key 3. Design-Time Considerations 4. File Exchange - Break It Down To Basics 5. Example 1 - Simple Bench Hold-Down Templates 6. Example 2 - Electronics Cavity Routing Template Set ----==---- 1. Finding Your Laser Okay, well we have two options for getting our templates made. First - getting your hands dirty at a Makerspace, Hacklab, community college/educational facility or wherever else offers public/membership access to a suitable laser cutter. By far, this is the best way of extending your skill set; your time can be spent fine-tuning (or replacing!) your templates hands-on. You have end to end control. This might be a bit more costly in the short term; mandatory safe usage courses and basic fees are a necessary price to pay. You'll probably burn through a lot of material (joke not intended, but apt) in your first attempts too. It's definitely a swift and easy complete control solution once you've ticked those boxes, and the cheapest route for the habitual user. The scope of this article is not intended to take any precedence over the advice you're given during laser cutter induction. Every location will have its own set of house rules, so rely on their expertise and recommendations. Every laser is different, every facility is different. The tutors who do this are your gurus, so drop preconceptions and let them guide you. The other option is reliance on third-party services. These can vary from brick-and-mortar shop/bureaus like Mostly Out Of Cardboard, turnkey online services such as Ponoko or specialist guitar supply companies with in-house custom laser cutting such as Guitars and Woods. Third party services are not necessarily an inferior choice or even an expensive one, however you do need to shop around for a service which understands your requirements and preferably does this work all of the time. Your local trophy maker "who happens to have a laser" might charge you well over the odds for the inconvenience of reconfiguring their machine for a one-off sheet job, however simple. It might simply not pay as much money on the hour as their normal line of work, or be an alien process to them. Even a shop signage maker who cuts sheet day-in day-out might not offer an attractive price on small one-off jobs. Third-party services have the advantage of experienced operators, and you should use that. Ask if they've cut templates for luthiers or woodworkers before. Familiarity - or at least an understanding - of what you're wanting to achieve is 90% of the battle won. If they've done anything similar before, they might be able to suggest improvements on your basic design for future work or simply snag any errors in your work submissions. If they haven't, gauge whether they're open to the idea of what you're wanting and understand its purpose. Companies that are genuinely interested in your product and having you as a satisfied customer are worth fostering a relationship with....as long as that isn't simply a way of sleazing deeper into your wallet! A lot of creative and inspirational people work in laser cutting services, Makerspaces and community colleges. Often the opportunity to collaborate on something new and exciting (as exciting as router templates get?) is more important to them than a bit of time or turning a quick buck. Some operators are genuinely excited just to see new things come off the laser and might be happy just for the cost of materials. "Head towards the people that have that creative spark and not the jaded old farts who might just see you as an inconvenient interruption to their non-stop conveyor belt of boring paint-by-numbers imported Chinese component school sport's day trophies given out just for participating rather than representing real achievement." - Benjamin Franklin ----==---- 2. Starting Out - Communication Is Key The people you need to be on friendly speaking terms with from day one are the keyturners or regular users, whether they're engineers on the other end of the phone, colleagues, Makerspace tutors or fellow denizens; whoever. Laser cutting is a fairly simple process with a few hidden tricks and obstacles you need know before you encounter them. Communicating your needs and existing knowledge will produce a smoother process from your desktop to the finished item. Design Protocols There are basic conventions within drawings which denote how the laser driver will interpret the job. We'll look at these later, however you should ask your service what their own in-house conventions are, or check with the other people in your Makerspace, etc. how to set up the drawing appropriately to work with the default laser configuration (this should be covered during safe usage courses). Firstly this saves time fixing things in the mix, or worse, trashing good material. Most importantly it may ease third-party setup charges if your drawing is good to go straight to the laser. It definitely gives you room to negotiate that cost. It has to be borne in mind that services will likely operate an hour rate on setup. These charges are superfluous when a drawing is poorly designed or doesn't conform to house protocols and needs the attention of an engineer or operator! We have a dedicated thread on laser cutting over on the Forums. If you're wanting to send jobs out to cut, but are unsure on whether your design is completely appropriate for that purpose, join the conversation and we can fix most things up! Material Selection Not all Makerspaces or third-party services have a full selection of materials on-hand. Prices may also vary due to wastage, availability and basic markup. Plywood designed specifically for laser work tends to be more expensive as it has to be free of knots and voids, plus needs to use glues safe for laser cutting. Acrylic will be (well, should be) tempered cell cast due to problems with cracking and poor finish quality with the extruded variety. The right materials cost a little more, but produce infinitely better and more durable results. Thicker materials can come with unexpected side effects, such as larger kerf (width of cut left by the laser) sizes or cut edges which are not perpendicular to the face. Thinner stock is a more accurate choice for closer-fitting parts. This is a good subject to discuss with the users/owners of the laser; if theirs has the right optics and power to cut 1/2" acrylic perfectly then go for it! Ask for advice on choice and comparative costings with stock materials; you might even get a great deal on a job if something can be pulled from the offcut bin. Asking the question costs nothing and can save you a significant amount of money. Exchange File Format More than likely you'll do your design work away from the site where the laser is located, and probably using different software also. Modern laser cutter drivers are far more forgiving of input formats than they were a few years ago, however that isn't to say that every bug has been rattled out. Choosing the most appropriate format for file exchange from your machine to that of the laser is vital. If you're going third-party, as what their preferred file format is and perhaps what software they are using; if you both happen to be using CorelDRAW you can cut out unnecessary conversion steps and swap native file formats directly. I prefer DXF (Wikipedia) simply because it is the most common and interoperable file format for vector information. The same rationale applies to other packages (Inkscape, Illustrator, etc) where exporting to a widely-supported basic file type removes most common errors from translating across formats. "What-You-Get" If you're using a third-party service, ensure they are aware which cut pieces you're actually needing from the job. A negative space router template (such as a pickup cavity) may not be immediately obvious, leading to problems where you receive a "Tele pickup shaped piece of Masonite" in the mail instead of the surrounding template for cutting the cavity! Explicitly stating, "This is for a 200mm x 150mm rectangle of Masonite with that shape cut out" makes all the difference. For more complex jobs where you are needing both the negative and positive components from the cut, again, state this from the outset. It saves a lot of time and hassle. Not all laser services will know what a router template is or its end use. Obviously this is less of a problem when you're cutting work under your own steam. One issue that might crop up is when cutting out fine components. Air assist which prevents flareups will happily blow your valuable but newly-loose parts around the bed, or worse, into an exhaust port! A little double-sided tape under the material in the right places and the use of a spoil board underneath helps. Whilst this isn't a communication issue, double-checking with a third-party service that they use the same kind of approach is. ----==---- 3. Design-Time Considerations Keeping a design as simple and to the point as possible wins the day. Only add as much information as the templates really need. The true test of a template is in the quality of the workpiece it produces; not how tricked out the template is with text, logos and irrelevant detail. This is especially important if the service charges by time or in the case of Ponoko, a function of total laser work movement length! Going through your design from top to bottom pays off. Common problems that are not immediately apparent can be revealed by developing your own methodical approach to validating your designs. Alignment Marks - Transparent Materials Acrylic offers us a great opportunity to add engraved markings that can be seen through the template itself. The problem is that lasers cut from the top down. This just requires that the finalised design is mirrored prior to sending out for cut so engraved text will appear correctly when viewed through the template, plus alignment marks lay directly next to the workpiece. click to enlarge Alignment Marks - Opaque Materials Opaque materials such as Masonite or MDF may be difficult to reconcile with alignment marks such as a centreline; after all, engraved marks will be placed onto the top surface of the template and we can't see through the material like we can with transparent acrylic. For most cases, this is not too problematic; we can add additional auxiliary cutouts within a template to assist with alignment where it might not otherwise be possible. In the example above, diamond-shaped auxiliary alignment cutouts allow the template to be placed accurately on a marked centreline using internal corners rather than approximating from a top-engraved marking at an oblique angle to the edge. This is also invaluable for alignment on angled headstocks, where the centreline falls away past the nut area. Work Layers Use of separable layers improves workflow. Placing all engraving work onto a separate layer to cutting makes it a simple task to confirm that paths are not duplicated, incorrectly set and properly aligned, etc. Colour within the drawing is used as the primary guide for different laser settings. Most laser driver software can be configured so that many different colours to represent various combinations of speeds, powers and duty cycle frequencies. The accepted basic standard is that red (RGB 255,0,0 - #FF0000) represents a cut and blue (RGB 0,0,255 - #0000FF) represents an engraved line. If using a third party, confirm their house rules and conventions on colours and whether line weight is a consideration. My personal arrangement is to use black (RGB 0,0,0 - #00000) to denote the rectangular working outline for larger negative templates. Some houses may interpret this as an engraved mark unless it is explicitly stated that black represents a cut. Ensure that your drawing objects are explicitly set to the correct colours, not simply "By Layer". If your software has the ability to "select all items by colour", this helps with confirmation. Another check is altering layer colours to something unused, such as bright green.....if any objects are set to follow colour by layer, they'll stand out clearly. Kerfs Laser cutting produces small but still significant kerfs, or the "width of cut". Several factors such as material type and thickness affects the final size of kerf, however it is usually in the region of 0,15mm for thinner materials. Confirm with the laser operators what the expected kerf size of the material you are working with is, or make test cuts and physically measure it yourself. A typical kerf is in the region of 0,2mm and equates to an offset of around 0,1mm from the expected drawn outline. Kerfs are hardly worth concerning yourself with for headstock and body templates, and in fact it works in your favour for bolt-on neck/heels. Other precision joinery Items that require a tight conforming fit - such as set neck joint templates - will need test cuts to be made and the templates proofed for suitability. Offsetting the mortise half the kerf size smaller and the tenon half larger is a good start, however the proof is in how well the joints routed using the templates mate together. Adding in a larger offset than is necessary is also an option. It's better to fine tune the wood with some sandpaper than it is to have it loose straight off the router! ----==---- 5. File Exchange - Break It Down To Basics Many of the design tools in various CAD packages produce complex objects that are often handled in a manner specific to that package. For example, different types of curves, mathematically-generated contours or even text objects. Unless you are working in the exact same software that outputs jobs to the laser, the two different packages can have radically-different opinions on what how your work is supposed to render, resulting in incomplete or incorrect cuts by the laser. We can work through this by taking complex items and devolving them down into basic objects (called Primitives) that are unambiguous and are rendered equally by all software packages. A common error is font usage. They'll happily render within the package they were created within, however there is no guarantee that this will translate through to the finished product. Take the following example in TurboCAD: click to enlarge It might not seem immediately obvious that any kind of problem might exist here other than the font being solid rather than an outline. Times New Roman is a vector font, which might seem pretty universal to most systems. However, once this work is saved out to the common DXF format and re-opened in the software used for the laser (in this instance CorelDRAW for an Epilog platform) we see that the font has been substituted to a completely different one, and is no longer mirrored as in TurboCAD. How to we prevent file format exchange errors such as these? click to enlarge Complex to Simple (or "Simple > Complex") CAD packages have all kind of tools for producing high-level objects. Underneath it all, these objects are still built from a basic set of Primitives, such as lines and circles. Instructing your software to take each high-level object and strip away the complexity varies from package to package, however is usually called Explode. In the example above, taking the text object in TurboCAD and Exploding it down into Primitives should allow any other package to interpret it correctly. Often this will need to be performed more than once depending on the object being Exploded. For TurboCAD, this needs to be carried out twice in order to devolve the Text object to a single Group of objects, then down to individual Primitives (normally Polylines). However your own software works, inspect the objects to figure out whether they need Exploding further. Some objects such as characters within Text may Explode down into two individual parts; the fill and the outline. Deleting any fill prevents duplication of the same object, since we only need text character outlines. click to enlarge - a letter "O" Exploded down into internal and external polyline shapes. It is also worthwhile considering Exploding curves; whilst simple curves normally render correctly between different software packages, they usually cause the laser head to move slower than with sets of lines as the driver interprets the curve mathematically. Exploding a curve down into discrete Polyline objects is recommended to reduce job complexity and increase speed. Before committing, compare how granular a Polyline is in comparison to the original curve. Most software allows you to define how finely a curve is broken down into a Polyline. For most jobs, a cut made using Polylines is indistinguishable from one made with curves. Once you have a better understanding of which objects translate well via your chosen file exchange format, you can Explode only the ones that don't. Ultimately, if the end product cuts quickly and efficiently, breaking your drawing down to its absolute basics prevents unexpected bugs from creeping into your designs. ----==---- 6. Example 1 - Simple Bench Hold-Down Templates A few months ago, I sent out a quick turnaround job to Henri at Mostly Out Of Cardboard (MOoCB) for some acrylic pin routing templates. The files were supplied as individual DXFs. Each holddown consists of an outline plus several holes used for aligning and stacking pieces together. Henri simply imported the DXF files into CorelDRAW, set each outline for the appropriate cutting settings in the laser job driver. Being extremely simple, Henri was happy to accept the DXF files as-is straight from my CAD package and set colours for cutting, etc. at his end. ----==---- DEMO FILES - 125mm offset holddown.DXF - 175mm offset holddown.DXF - 200mm offset holddown.DXF preview of 125mm offset holddown.DXF ----==---- On my doorstep the next day I had these (love the packaging): This was an extremely simple job, which required very little back-and-forth communication. Henri is experienced at cutting a great number of different materials, so three small acrylic components was a walk in the park. In fact, I asked for "whatever light acrylic stock" they have on hand which resulted in these 4mm. A job such as this is mostly material cost with minimal setup time; even the packaging is only a minute job on top of the parts themselves. Like any job, there will be a degree of setup on some level, whether it be a complete treatment and check of the vector file sent (some bureaus insist on this, and make the charge mandatory...) copy grouping parts for efficient batch cutting or laser configuration (origin locating, focusing, etc) prior to running the job. The templates worked fantastically. 8mm-thick Oak blanks were pre-drilled and bolted down to the sled and shaped using an overhead pin router. The templates seat underneath and the pin rides against them. A very simple and neat use of laser-cut templates! ----==---- 7. Example 2 - Electronics Cavity Routing Template Set Anybody that knows me enough will be aware that I think far too much about the classic basses that came out of the Matsumoku factory in Japan from the late 70s to the late 80s. The most known of those is the Aria Pro II SB-1000 with its tank-like dual-mode 18v electronics and recognisable signature sound. A slow-burning project of mine has been to make a more or less authentic replica of the SB-1000, but with altered specifications....and a fifth string. The electronics cavity is something I'd like to replicate rather than make "similar to", so I recorded the measurements from a real SB-1000 and drew the cavity up in CAD with a few basic improvements and some cleanup. An original SB-1000 electronics cavity, bereft of life. Whilst not the most elegant or precise of electronics cavities, the space for the preamp module and batteries, plus the recesses produce a nicely-organised electronics cavity that isn't thin and weak like most "swimming pool" cavities. I figured that a set of four templates would be perfect. The first being the main outline of the cavity cover recess and cover plates (the plate is split into two pieces), a template for the main "body" of the rout down from the outer cover plus the narrower part of the battery/preamp niche, an auxiliary template to produce the wider ledge either side plus a template for the recesses. Since these templates are all related to each other, I decided that it would be useful to have engraved alignment markings on the lower face along with some basic information to remind me what to do (or not to do). As mentioned previously, lasers only cut from the top down, so engraving on the lower face means these will all need to be cut in mirror image. A vector line font was used for the text for both clarity and simplicity. Screwhole locations were marked with 2,5mm diameter circles with Point objects (crosses) engraved in their centre. The Points were Exploded down into Line pairs. A potential issue would be duplicating the cavity cover split Line. Since I drew the whole outline and added the split later, this was no problem. A look at the layer manager ("design director") shows that I defined several layers for this project. Each one contains references and guidelines, text labels or the work for the laser. This helped me create a template set from one master drawing, with the organisation allowing me to work on all of the templates as a group or individually. Turning on all of the layers shows how everything was designed. A bit of a nightmare when you look at it like this, but it works! Diary of a CADman (ergh.....) TurboCAD allows me to electively export specific objects to DXF files, so I selected the objects relevant to each template and sent them out to four individual DXF files. As you would expect, all Text, Arc, Point, etc. objects were Exploded to Lines and Polylines. I contacted Guitars and Woods to produce my template set in 5mm acrylic along with a few different designs. G&W sell templates for many common guitar designs (Strat, Tele, Flying V, etc.) and do all of their cutting in-house. Since they know the product and a luthier's needs, it seemed perfect to use them for these templates. After an email exchange with G&W on their convention on cutting and engraving colours, material availability, pricing, that DXF was an appropriate exchange format, that the outline was denoted by the outer black rectangle, etc. I sent the four DXFs to cut. Just over a week down the line we received this tidy little package.... click to enlarge So here's that first template described earlier. The alignment crosses and text appear the right way around and are engraved on the underside. Each screw/threaded insert location has the small hole for punching and the alignment marks. I used the kerf of the laser (~0,15mm) to my advantage; the cavity cover plates will drop in perfectly. click to enlarge The cavity cover recess will of course require a thicker (and wider) template to be made up since it is only meant for a 2mm cut depth. I don't think router cutters are even available that shallow! Nonetheless, marking out the location internally is important and a transparent template is excellent for alignment purposes.... click to enlarge ....due to how the other templates were designed. The outline of the cavity cover recess is replicated here as an engraved reference on the underside. By aligning this with an outline drawn using the first template (or marking off the outline since the templates are all cut from 250mm x 120mm pieces!) we have an accurate placement for each subsequent template. click to enlarge The auxiliary template is shaped similarly, but is only used for the battery ledge. click to enlarge Finally, the control recesses. click to enlarge I labelled the templates 1 through 4 and added pertinent routing information to each one. In most instances, these templates would be retained as "master templates" and copied across to a thicker sacrificial material such as Masonite, plywood or MDF. ----==---- In Closing Access to and use of laser cutting services is far easier than you might expect. Maker culture has gone a long way towards normalising this sort of technology almost into everyday life; taking advantage of that as a luthier is a simple and economical step in taking your work forward in huge bounds. Over on the ProjectGuitar.com forums we've opened up a Laser Cutting Discussion And Advice Thread. We hope this article has inspired you with new ideas and methods of producing your instruments; ask anything you want about laser cutters, designing templates or components, CAD-related issues or even service recommendations. http://www.projectguitar.com/forums/topic/48625-laser-cutting-discussion-and-advice-thread/ ----==---- www.patreon.com/ProjectGuitar This article was made possible by the generous donation our our Patreon supporters, plus invaluable input and assistance from Henri at Mostly Of Of Cardboard and Carlos of the Guitars and Woods web store. Cheers guys! If you enjoyed and benefitted from this article. become a Patron of ProjectGuitar.com and help us bring you even more articles, tutorials and product reviews like this, week-in week-out! Thanks to ProjectGuitar.com's Patrons sirspens a2k Chris G KnightroExpress Stavromulabeta Andyjr1515 sdshirtman djobson101 ScottR Buter curtisa Prostheta 10pizza verhoevenc VanKirk rhoads56 Chip
Prostheta posted a tutorial in Instrument BuildingLast week we introduced the idea of adding guide bushings to your router's accessories. To help us understand how we use them in practice, we'll start by taking a second look at routing a simple soapbar cavity and we adjust template sizing for guide bushing use. In spite of being pretty much the most simple type of rout, rectangular soapbar pickups require attention to the internal corner radii which makes them perfect for routing with a guide bushing. But why? The EMG rout we used to demonstrate the simple technique needed corners smaller than most bearing-guided router bits can manage, so we drilled them by hand before routing the rest of the cavity. Not the most graceful method, but definitely a simple and easy trick that anybody can manage with on-hand tools. Introducing guide bushings into the mix makes this into a single-step process, with the added bonuses of reliability, perfect results and almost zero effort requirement. EMG soapbar corner radius - 1/8" or 3,175mm We titled this tutorial "intermediate" purely because it should satisfy the demands of all but the most exacting of builders. Since everything in this series serves as building blocks to increase your knowledge and ability, we'll take this one to the logical extreme later in a separate article to illustrate just how far we can take everything with our routing wizardry. ----==---- Overview and Objectives Most of this tutorial will be similar to the working practices introduced in Router Basics: Simple Soapbar Pickup Routing however Router Basics: Humbucker Pickup Routing (with Pickup Ring) and Router Basics: Guide Bushings contain useful information and ideas applicable to this tutorial also; if you haven't had chance to absorb these yet, they'll definitely get you up to speed. The linchpin of successful routing with guide bushings is the same as any complex job; good working templates. We'll describe the process of developing templates using the familiar EMG bass soapbar "standard". To open out the idea a little, we'll show how to make the template adjustable so that it can rout all three of the EMG soapbar sizes (35, 40, 45) similar to the template introduced in the simple humbucker routing earlier in the series. The same concepts and calculations can be scaled to cover rectangular routing templates of any dimension or end use, whether it be recessing a bridge or a rear tremolo cover plate. The underlying objective of this tutorial is to enable you to take onboard the basic concepts of template-making for guide bushing router jobs. We'll tackle more complex guide bushing routing tasks as we go through the series, building on these core ideas and how we can counter exceptions and weird difficult jobs. ----==---- How Soapbar Guide Bushing Templates Work Instead of a bearing running against the internal sides of the template, the bushing does the guiding work. Since a guide bushing's diameter is larger than that of the cutter passing through it, the templates internal dimensions need to be compensated by being offset in a size to match the difference between the bushing and the cutter. Beyond this distinction, the templates are built and function in exactly the same way as those for bearing-guided flush-cut template bits (surely there's a shorter name for those....). Routing with a guide bushing Since this is only an intermediate tutorial, we'll be relying on simple square-cornered templates illustrated above. More experienced template-makers will use rounded corners that are specifically radiused to guide a small cutter around internal corners instead of into them. The difference is subtle, so we'll deal with the basics before taking on more esoteric ideas. ----==---- What We Need Making the templates only requires that we have clean dimensioned template stock such as MDF, plywood, Masonite, etc. Generally this only needs to be slightly thicker than how far the guide bushing sticks out from your router. Slightly thicker stock helps us glue and screw our completed templates so 1/2" or more is easier to work with. You can always make your template using whichever stock is most convenient at the time and then copy it down permanently to more appropriate material later. Hand router (plunge base preferred) Small straight template cutter with radius appropriate for the pickup (see Calculating The Offset) Sheet stock suitable for templating (plywood, MDF, etc) cut into strips or sized with two 90° edges (see Building The Template) Wood glue Screws Shim stock (optional) Sheet stock for thin permanent templates (optional) Countersink (optional) ----==---- Calculating The Offset The offset value is derived from the diameter of the cutter and guide bushings in use. Firstly, we need to select the diameter of router cutter we want to be using and then a guide bushing most appropriate for use with that size cutter. After we've done this, we can calculate the basic offset and make adjustments. Cutter Size Choosing the router cutter is based on the corner radius of the pickup housing. EMG soapbars have a corner radius of 1/8", requiring a minimum of a 1/4" (6,35mm) diameter cutter (double the corner radius). As discussed in the previous article on soapbars, we add an "easing" gap around the perimeter of the pickup to increase the cavity size slightly to allow for the finish thickness, etc. This also requires an increase in the size of the corner radius so that the outline of the cavity follows the shape of the pickup corners. Layout of an EMG-35 size soapbar showing corner radii/diameters and the result of 1mm of perimeter easing The diagram above demonstrates simply how 1mm of perimeter easing increases the choice of cutter size from 1/4" to just over 8mm or 5/16". It isn't always possible to find the exact radius cutter to match this value, however the nearest size is fine in most circumstances so 8mm is golden. 3/8" or 10mm would definitely be too large. Easing around a soapbar cavity (reminds me of Joe's Garage) Bushing Size Generally-speaking, we should aim to select a guide bushing which is the closest size to our cutter. This produces a smaller and more manageable offset. Even though this isn't a hard and fast rule, the smaller the bushing used the more stability the router has on the template. That's always a good thing however you look at it! For the example above, an 8mm cutter (just under 5/16ths) will need a guide bushing with an internal diameter at least that size. My own set has a 7/16ths (11,11mm) bushing with an internal diameter of 11/32nds (8,73mm). That's a little tight for my tastes, since chip waste could get trapped between the cutter and the inside face of the bushing. The next size up is the 1/2" (12,7mm) bushing with an internal diameter of 13/32nds (10,32mm) which is pretty much a perfect match. Doing The Math The photo below shows a cutter fitted into a router with a guide bushing attached. The offset value is the closest distance that the guide bushing will allow the router cutter to get to the template edges. This is calculated by subtracting the diameter of the router cutter from the outer diameter of the guide bushing, and then dividing the result by two. Visual explanation of figuring out your offset value For our 8mm cutter in a 1/2" (12,7mm) bushing, this gives us an offset of: (12,7 - 8) / 2 4,7 / 2 = 2.35mm Taking into account that we also want 1mm of easing around the perimeter, we add that to the basic offset to give us our final offset value, 3,35mm. Now we've got this figured out, we can move onto measuring out our template..... ----==---- Building The Template Our templates will be made from any sort of sheet stock or thin dimensioned wood. Unlike templates made for bearing-guided bits which benefit from being thicker, guide bushing templates only need to be as thick as the amount that the bushing protrudes below the router base. For assembly however, thicker material allows us to produce adjustable templates plus we can glue and screw the components. The option to copy these templates down to thin stock after making them in thicker stock works too. Two easy options are available for making the basic template. We can either use the fenced approach as we did for simple soapbar routing or we can make it stacked similar to that for simple humbucker routs. Mostly this choice depends on your ability to accurately dimension your template sheet stock. If you're able to cut wood to exact widths on a table saw, through a thickness planer, drum sander, etc. then the stacked template is the way to go for you. A fenced template is easier and can be made with minimal tools and materials as long as we have four pieces with two clean 90° edges. Comparison of a stacked plywood template (left) and fenced MDF template (right) Making A Fenced Template Fenced templates need four pieces of stock with two flat perpendicular sides each. As the name implies, these fit together to form a fence around the object we're templating. : A simple fenced template Rather than simply copying the outline of the pickup as per the example above, we need to expand that outline to take into account the offset that we calculated earlier. The easiest way for us to do this is by shimming the pickup outline using veneer, plastic card or other thin pieces of material of known thickness. This works like so: Shimming the pickup using four pieces of 3,35mm thicknessed wood It might seem obvious that we don't need to shim all four sides 3,35mm....but this works for illustration; in reality it's far easier to shim two sides using a double-thickness of shims (6,7mm). Either method is valid, it simply comes down to materials you have on hand. A surprising number of common household objects could be used....a credit card is 0,76mm (0,03") thick, so cut them up! Full-size SD cards are exactly 2,1mm (0,083") thick. Since we're only using them temporarily as shims, we can get away with all kinds of materials. Shimming doesn't need to be an exact science here. Even though we're aiming for a specific value (in this case 3,35mm/6,7mm) we can always go a little either side of this as long as we understand what that will do to the template. For instance, if we used three SD cards either side (2,1mm x 3 = 6,3mm or 0,25") we're undershooting by (6,7 - 6,3) / 2 = 0,2mm (~0,008") each side. This isn't a lot and it shouldn't affect the end result visibly. Equally, using a stack of nine pieces of a credit card overshoots by less than a tenth of a mm. Far smaller than most people's working tolerances. Just confirm that the internal dimensions of the fenced template end up where they are expected to be once you've assembled everything in place. For an EMG-35 (3,5" x 1,5" / 88,9mm x 38,1mm) with an eased offset of 3,35mm we need an internal area of: (88,9 + 3,35 + 3,35) x (38,1 + 3,35 + 3,35) 95,6mm x 44,8mm (3,76" x 1,76") We now have the choice of glueing/screwing together this fenced template, or sticking it down for copying to permanent templating stock. Just remember to confirm that the internal dimensions of your fenced template correspond to calculated values. If you have the resources, custom thickness shim stock can be thicknessed with a drum sander, a thickness planing jig or even a Myka neck pocketing jig set to 0°. In a pinch you could even use the internal measuring jaws of your calipers to set everything in place! Making A Stacked Template If you are able to produce template stock to exacting widths, we can work primarily from the numbers and directly cut our template parts accordingly. For soapbar templates, this only requires us to make strips of template stock corresponding to the width of the template negative space, and that these can be crosscut with accuracy. The same calculations used to check the internal dimensions of the fenced template apply here also. In the instance of an EMG-35 sized housing with 1mm of easing, we can produce a stacked template using strips of wood cut to 44,8mm thickness. For my own part, I cut strips at 50mm on the table, jointer planed one edge and thickness planed them down gradually until the exact size of 44,8mm read off my calipers. These strips were then crosscut on a table saw to produce two long outer pieces and two shorter inner pieces. The only parts that needed to be a very specific width are the "surrogate" parts used to space out the template. These can either be cut on a table saw (if you can do this accurately) or by hand with your fret slotting mitre box. The general layout of the template is as follows: Layout of a precision stacked template - click to enlarge The internal space is defined by using precision-cut surrogate parts. I produced one for each size of EMG soapbar, taking into account the eased dimensions. It's worthwhile marking out the original dimensions in addition to the modified ones along with the offset built in. The template parts are assembled and glued into two identical halves, exactly in the same way as the adjustable humbucker template. For details on how to create the location holes, check that for a full pictorial. "She may not look like much, but she's got it where it counts, kid. I've made a lot of special modifications myself." Locating dowels allow the template to be assembled to work for all three EMG soapbar sizes: Templates can look rough and ready as long as they do their intended job as expected Copying The Template To Thinner Stock Optionally, we can use these thick master templates to create "working templates" in thinner stock. Whilst thick plywood such as this is excellent for constructing templates, it can reduce the maximum working plunge depth of our router. Check the clearance required for your bushing and select stock appropriate to that thickness before making a copy with a bearing-guide template cutter. Since bearing-guided cutters will leave their radius in the corners of the copy, use a bit smaller in diameter than the smallest guide bushing you might use so these don't interfere with the template in use. Remember to back your workpiece up with scrap before routing all the way through! ----==---- Using A Guide Bushing Template Use is very simple from this point onwards, and much like any other template routing operation. The bushing enables the routing to be carried out with small passes to ensure clean tearout-free work. Dust extraction may be difficult with a guide bushing in place, so take time to clean the rout out directly with your extractor hose. Mounting the template to the workpiece is best done with four pieces of double-stick tape in all four corners to prevent movement. Router and template set up, ready to go. Two shallow passes did the trick Finished rout! ----==---- Improving The Templates The relative simplicity of guide bushing templates doesn't leave much room for improvement! The same basic addition as per the templates described in previous articles apply here also; drilling through from the underside and countersinking from the top to create centre and cross locating holes. We'd be interested to hear your comments and ideas on other improvements however, so pop down to the comments section and share your thoughts.... ----==---- In Closing.... Simple guide bushing templates such as these are easy and quick to make, so much so that you can quickly find all kinds of places to use them in your work. We hope that this tutorial has inspired new ideas and we'd like to see how you use your new superpowers! Happy routing..... ----==---- www.patreon.com/ProjectGuitar If you enjoyed and benefited from this article. become a Patron of ProjectGuitar.com and help us actively continue bring you even more articles, tutorials and product reviews like this, week-in week-out. We appreciate your feedback in the comments section, and we hope you enjoyed this tutorial as much as we did compiling it! This tutorial was made possible by ProjectGuitar.com's Patrons sirspens a2k Chris G KnightroExpress Stavromulabeta Andyjr1515 sdshirtman djobson101 ScottR Buter curtisa Prostheta 10pizza verhoevenc VanKirk rhoads56 Chip
Much as a router is an essential upgrade to any luthier's arsenal, guide bushings can upgrade your routing work to a new level of versatility. They allow for safer working options and in combination with well thought out templates/jigs, a more powerful way to rout work; often in ways that are impossible with standard bearing-guided cutters. Anybody that has experience in fine woodworking outside of instruments may have used or heard of legendary work jigs such as the Leigh Dovetail system or similar. Systems such as these leverage the power of router guide bushings to produce perfect dovetail joints in cabinetry work or carry out other complex precision tasks. Whilst we don't see as much of that level of work in musical instrument making (perhaps in DIY cabs/amp heads or acoustic neck dovetails) it doesn't mean that guide bushings are of no use to us. Nothing could be further from the truth. Breaking down how a guide bushing functions and what advantages they have to offer for our work allows us to develop jigs and systems that are just as meaningful and powerful. Guide bushings can produce complex pickup routs in single passes, produce shallow recesses for bridges/plates or allow cutters to be used in ways that are impossible otherwise. Guide bushings are a capable and inexpensive upgrade, however they don't see their way into instrument-making as much as they should. This introduction is designed to raise awareness of their importance and how to select the right guide bushing system for your router. Subsequent articles in the Router Basics series will provide practical working examples and hopefully inspire you to use them in new and original ways to work smarter. ----==---- So What Is A Guide Bushing? Guide bushings are a distant relative of the bearing found on a bearing-guided cutter. Anybody that has done any kind of work around an instrument with a router will know how a bearing-guided router cutter works; the cutter's bearing runs against either the workpiece or template, whilst the cutter itself shapes a specific profile into the wood. For jobs like flush-trim cutting, template copy routing or adding chamfers/roundovers, bearing-guided cutters are normally the best solution. Many processes around an instrument soon show the limitations of bearing-guided cutters, easily leading to tool bloat ("a different cutter for every single job") or seemingly-simple jobs becoming a series of steps to get past the goal. Guide bushings allow a small range of simple inexpensive cutters to become powerful around a wide range of different tasks by taking over the function of a guide bearing. This is not to say that guide bushings make bearing-guided bits obsolete; more that each one can be more appropriate than the other in certain situations. A 25mm and 12mm diameter bearing-guided flush trim router bit Okay, Fine. So What Is A Guide Bushing? Guide bushings are a simple flanged metal or plastic collar fixed to the router base. The flange or bracket sits below the base surface whilst the collar extends a short distance below it, and is the part which runs against the template. The cutter plunges freely through the centre into the workpiece allowing for cuts at any depth. Secondly, the cutter no longer needs to have a minimum diameter unlike bearing-guided bits whose diameter is defined by the minimum physical size possible with bearings. Guide bushing fitted to a router base with cutter extending a short distance through This sounds fantastic; we can use any diameter cutter that will fit through a bushing and take cuts any any depth we choose. In most way it is, however there are considerations to be made when designing templates; the diameter of the bushing is larger than the cutter so there's an offset to calculate in. As tradeoffs go, this is a small one but seems the scariest to most people. We'll look in specific detail how to create templates that account for offset as part of later tutorials in Router Basics. For the moment, let's concentrate on how you can get your router equipped with an appropriate set of bushings! Choosing Your Guide Bushings (or do they choose you?) To the uninitiated, router guide bushings can seem like an impenetrable puzzle of sizes, brands and systems. Fundamentally, three broad types of bushing system are available, all of which perform the same function but vary in how they attach to your router base. Brand-Specific Most manufacturers produce bushings specifically for their routers which are usually simple and quick to fit, but restricted to working only with routers of that brand. Brand-specific bushings can be a premium-priced accessory, however the convenience of a bushing that works straight out of the box has to be balanced off with cost, especially if you use more than one router from different brands. The range of bushings that a manufacturer makes available will be limited in comparison with more universal systems, however this isn't to say that you are stuck without options. Most jobs that guide bushings excel at can be achieved using one or two workhorse bushings rather than an expansive collection of them. Bosch standard 17mm guide bushing. This one has almost built Rome over the last few years. Porter-Cable Several manufacturers (notably, DeWALT/ELU, Hitachi, Black & Decker and Makita amongst others) have adopted an unofficial standard in the Porter-Cable bushing style for many of their routers. They also happen to fit Porter Cable routers. Fundamentally, a Porter-Cable style bushing is a threaded flange with a knurled lock nut that fits into a 35mm (1-3/8") recess with a 30mm (1-3/16") through hole. Larger bases have either a 60mm (2-3/8") adaptor plate or a base-specific adaptor insert. Being a mostly US-based standard, Porter-Cable style bushings are overwhelmingly available in Imperial sizing only. This is in spite being originally based on a Metric fitting *cough*. That isn't a problem for anybody with two brain cells (and a calculator) to rub together, however. If you work in both systems, there's no time-wasting argument to be had. Porter-Cable is now my weapon of choice because of its simplicity, and that fact you can pick up a good set for a song on eBay, Amazon, etc. The broad market acceptance and availability of the Porter-Cable style has driven the price down, and they're so simple that there is zero qualitative difference between branded or off-brand. Other than friction burns to your wallet. A number of routing systems such as the Whiteside 9500 router inlay kit are based on the Porter-Cable style of fitting, making Porter-Cable a great option if you choose to go for a standardised system. The simple 30mm/35mm fitting dimensions make it an easy job to produce custom bases that accept a Porter-Cable bushings using two commonly-sized Metric Forstner bits. Inexpensive import Porter-Cable style brass bushing set (€20, $23? £18?) Universal Systems (Trend, etc.) Universal replacement baseplates such as the Trend Unibase allow you to move beyond brand-specific fittings or even use guide bushings for routers not originally designed for them. Like the unofficial Porter-Cable standard, the Trend sizing has its own set of dimensions based off the 60mm diameter flange which has become a "second standard" of sorts. To my knowledge, Trend provide the largest range of Imperial and Metric sizings of all systems, and off-brand bushings are also available. Check for compatibility with your routers! Unibases are an excellent blend of universality and turnkey convenience for anybody that doesn't want to mess around making new sub-bases for their routers. I however, do like making new sub-bases for my routers. Personally, I'm not too much of a fan of steel guide bushings or mounts that require screws. The base itself is fitted with threaded brass inserts (brass is naturally "sticky" and locks threads) which retains the screws better, however I imagine that even the slightest cross-threading to those inserts will leave you needing a new sub-base. I'm not the most graceful of people, and I imagine I would fall afoul of that sooner than most....nonetheless, the Unibase is as out-of-the-box as you can get for some. Worth considering! Trend Unibase aftermarket guide bushing system ----==---- Fitting A Guide Bushing (We'll look at the more involved alignment of a bushing in the tutorials) The Porter-Cable system is a straight drop-in solution for my Makita RT0700C router. The fixed base was designed to accept a bushing with zero modifications. Drop the bushing into the baseplate and screw on the knurled lock ring from the other side. This is easy when you can remove the motor from the base unlike most plunge routers. Makita RT0700C fixed base showing the mount, a guide bushing and knurled lock ring Brass is a soft but sticky metal. Steel bushings benefit from snugging up tight using a pair of pliers as steel vibrates loose, however hand-tight works fine for brass threading. Bushing fitted! The plunge base of my Makita RT0700C has a wider opening in the baseplate, designed to accept the "standard" adaptor plate. The plate is held in place by the two screws either side whilst the guide bushing mates with the adaptor itself. Given how inexpensive the guide bushing set was, it's a bona-fide bargain upgrade for this router's working capabilities. ----==---- Do I Have Need Of Guide Bushings? Yes and no, I think. They're not impossible to get by without, and in fact many luthiers go through their entire careers without use of them. Take that how you will of course. As a way of extending the capabilities of what you are able to do right now, they're an important consideration and worth some thought. The same week as I write this, I had a perimeter flush-trim routing job which would have benefitted from a bit of guide bushing action to make safer by reducing excess material closer to the finished edge. I decided not to use one, however it would have been a simple 5-min job that could make the difference between a job going pear-shaped and going perfectly. It went perfectly anyway, but that few dollars of brass might have been what saved a few dozen dollars of wood getting blown to pieces. We'll look at that case in a full tutorial elsewhere in the series. Do you need to be using guide bushings? It's probably better to ask why you're not using them.... Do I Need Just One Or A Full Set Of Guide Bushings? That's up to you really, and that all hinges on how far you want to take your work in terms of complexity. A single bushing size will open up a lot of working possibilities on its own. For example, my old crappy router only accepts Bosch-made bushings unless a custom or universal baseplate is added. I've done many jobs with that successfully using the single 17mm bushing that came with it! Some jobs do make more sense when you size the bushing nearer to the cutter, and vice versa. Equally, you can make all kinds of jigs for guide bushings based around one very specific size. I've had a lot of mileage out of that 17mm bushing! ----==---- In Closing Later in the series, we'll take another look at routing for a soapbar using guide bushings instead of the simple drilling/routing technique introduced earlier. We'll then build on this to extend the use of guide bushings out into other more complex tasks and templating designs. We'll see you then! ----==---- www.patreon.com/ProjectGuitar If you enjoyed and benefited from this article. become a Patron of ProjectGuitar.com and help us actively continue bring you even more articles, tutorials and product reviews like this, week-in week-out. We appreciate your feedback in the comments section, and we hope you enjoyed this article as much as we did bring it to you! Special thanks go out to Andrew Knight (@KnightroExpress), also guilty of using a Makita RT0700C with the Porter Cable bushings. This article was made possible by ProjectGuitar.com's Patrons sirspens a2k Chris G KnightroExpress Stavromulabeta Andyjr1515 sdshirtman djobson101 ScottR Buter curtisa Prostheta 10pizza verhoevenc VanKirk rhoads56 Chip
Prostheta posted a tutorial in Instrument BuildingCommercially-made routing templates for humbuckers are easy to find from virtually all good luthiery supply outlets these days. They're a fantastic turnkey solution for carrying out this common task. Beyond the "standard" sizes, templates for larger pickups are thin on the ground meaning that we end up making them ourselves. Standard or not, the process of making a template for any humbucker-style pickup is the same and it's not a huge leap to tweak the dimension to fit a variety of pickup sizes such as mini humbuckers, etc. Pickups fitted into pickguards or under a pickup ring don't need tailored routs; we don't see them on the finished instrument. This isn't to say that we can butcher them in, just that we only need to concentrate on their functionality and fitness for purpose over their cosmetic value. A more complex tutorial for pickup routs tailor-made to the exact dimensions and corner radii for a "showy" exposed rout and direct mounting will come later in this series. That is not to say these routs can't be executed with precision and beauty of course, but that's up to you! ----==---- Overview and Objectives This tutorial will take you through the creation of an easy but effective pickup routing template. Although the underlying method of constructing the template has been in use for decades, I expanded on it for use with a variety of modern pickup sizes and to incorporate the recessing to make it a single job rather than two. The system described is universal in that it will create routs to accept any "body with legs" style pickup with simple corner radiusing and provision for recesses for the legs/screws. Since the outline of the rout will be hidden under the pickup ring, it just needs to be functional and do the job its intended for. First we'll look at how to make the template using a standard humbucker, and finally look at how to take measurements from any pickup/pickup ring and translate them through to your own custom template system. To keep the work simple and straightforward, we'll only be using a standard 1/2" diameter bearing-guided template cutter (12mm if you're Metric!). The template uses basic materials and techniques. The ideas and approaches discussed are designed to help you take onboard transferable skills that assist you in creating custom templates for anything, even beyond pickups. Definitely a good exercise towards becoming a next level template-making ninja! A cavity straight off the router with light sanding to remove the fuzzies - perfect ----==---- What We Need Pencil Ruler/Calipers Wood glue A router and a bearing-guided template cutter (1/2" diameter, 1/2"-3/4" length or shorter) Sheet stock suitable for templating (plywood, MDF, etc) cut into strips Double-sided tape Drill bits (optional) Wooden dowels (optional) Nothing that shouldn't already be on hand in your workshop! ----==---- How The Template Works The template consists of two identical halves which can either be glued together to make a permanent single-size template or pinned together to create a variety of different widths. Each half is designed to rout both the main cavity and with the inclusion of a specifically-sized insert, the deeper leg recesses also. Mockup showing the main template assembled The template exploded, showing both halves and the dowel locating system Template with auxiliary insert for leg recessing ----==---- A Quick Look At Humbucker Routs There's no real secret or magic going on behind the pickup ring. Enough wood needs to be missing in the middle that the pickup drops right in and either side so that the pickup height adjustment screws fit. Wood needs to be left at each corner for the pickup ring mounting screws. We could simply rout the entire thing to one depth, however that's just crude and we hold ourselves to a higher standard, right? We shouldn't need to remove more wood than we have to, and this template system makes it simple so there's no reason to go medieval. The pickup cavity (dark red) is hidden by the pickup ring, but leaves plenty of wood to fix the ring to the body ----==---- Template Construction The template system we'll be making is for a standard humbucker, made using simple stacked strips of wood or sheet stock. The only tool/skill we need is to be able to rip stock into strips of specific widths and cut the ends a neat 90° (another use for a fret slotting mitre box!). How you choose to make the strips of material is up to yourself; many options are available from cutting them on a table saw to sizing them using a thickness planer/sander or even using a router thicknessing jig! The only requirement is that the cut edges are clean and glue-able, and that you can manage making them to a reasonable level of precision. The template in this tutorial was made from 15mm thick Birch plywood, ripped into long 40mm, 20mm and 10mm strips on a table saw. These were them cut down to specific smaller lengths using a fret slotting mitre box. We'll discuss how those widths were arrived at later, and it'll be more meaningful if we look at the process first.... The stock we need is: 40mm (1,58") 2x 200mm or longer (7,87") 20mm (0,79") 2x 56,5mm (2,22") 1x 64,5mm (2,54") 10mm (0,39") 4x 64,0mm (2,52") 2x 72,0mm (2,84") In actuality, the only parts which need to be of a very very specific lengths are the three components for the auxiliary recessing template (10 x 64,5mm and 20 x 72mm) since the outline of the template isn't that important; only the internal components and edges where the router bearing will be running. Template stock cutdowns The strips were cut into the various calculated lengths and cleaned up. Laying them out over a printed paper template helps check for fit and alignment, plus we know we have everything and where it is! Download Printable Paper Template here! standard humbucker template layout.pdf Laying out using a printed drawing The auxiliary template for the pickup tab recesses is the part that the rest of the template should be physically built around, so assemble and glue this up first. The paper printout helps check that everything is sized and aligned, however double-checking the ends for squareness with scrap or a ruler ensures we're not building in any inaccuracies. Apply glue to the inner part's mating surfaces and adjust/assemble everything to that by hand. Put the assembly onto a flat surface, and push everything into correct alignment and let it sit for a minute or two so the glue starts to set up. Next, apply light clamping pressure whilst it dries. The small amount of setting up time helps stop parts shifting around under clamping pressure. You did check for alignment, right? Once this is dry, clean up the part from any squeezeout. A few tiny beads as pictured is about perfect for this work. Next, snug up the main parts of the template around the auxiliary template. Repeat the same process of gluing up all four parts of each template half, using the auxiliary template for reference to avoid any gaps or misalignments. Glueup can be done one part at a time or all at once. Masking tape applied to the top/bottom helps keep the parts from sliding around! Again, check check and check again at every stage. Looking good! Once we have the two outer halves assembled and cleaned up, we can either glue them both together to form a permanent one-size template or we can add a method of fitting the halves together temporarily. The simplest method is using simple wooden dowels which have enough retention strength to hold the template together, but can easily be released to alter the jig's size by placing them in holes corresponding to different set sizes. Clamping the workpiece down and drilling a hole through from one to another gives us an exact method of setting the jig up. One clamp holds the first half down, whilst the second holds both halves together. Drilling for the 8mm locating dowel - yes, I only have three fingers because I'm a Parktown Prawn.... After the first hole is drilled, a dowel is tapped in to secure both halves. The assembly is then flipped with the dowel in place, and a second hole/dowel added to the other side. Note that I added two alignment arrows indicating the size this "setting" is designed for. This was purely to counter my own future stupidity. Your own mileage may vary. Tapping in the locating dowel The finished adjustable template system should look something like this when complete. The dowels are removable for when different size settings need adding in. All that's left is to test fit a humbucker and pickup ring! The pickup has a little room to move in the cavity, allowing for angled pickup rings, finish, etc. The pickup ring completely covers the gap and the mounting screwholes have plenty of wood under them ----==---- The Template System In Use The main template can either be mounted using double-stick tape (about an inch square in each corner) or clamped either side. Positioning holes drilled through from the rear help position the template on the centre and cross lines. If the template is adjustable, each position will need its own specific centreline positioning hole....remember to mark them up meaningfully! The first step is to rout the leg/tab recesses to depth either side by fitting the auxiliary template. It should be snug in the centre; if not, use a piece of double-stick tape underneath or a piece of masking tape over the top to secure it. Bridge position humbucker rout on my Lancaster superstrat design The cutter used has a length of 15mm (around 5/8") which is perfect for this size template. Anything longer than the template is thick, and you soon find that the initial cut is going to be tough and unpredictable. You don't want the cutter trying to jump around before the bearing is even in the template, as that results in a dead template..... A 1/2" length 1/2" long cutter is perfect for this work. Mine is 12mm diameter, however that only means that the corner radii will be slightly tighter. Absolutely no problem since this is a hidden rout. After the initial cut, the radiused corners left by the cutter become apparent. After the recess has been taken to the full depth, the auxiliary template can be removed and flipped to do the other side. Perfect. That was about a minute's worth of work! We can now remove the auxiliary template and start work on routing the main cavity. Two passes and the target depth was achieved. Time to remove the template.... Aside from a little scorching and minor fuzzies, the rout is more or less good to go with no more work other than the cable drilling. A test fit is a good idea. Perfect. The actual pickup ring will be taller than this one so we have more than enough breathing room with the depths selected. ----==---- Calculating Your Own Dimensions Taking the basic idea of how this system works, we can extend it out to any width humbucker or even pickups of completely different sizes. ....For A 7-String Pickup For an adjustable style template, we don't even need to make a new auxiliary insert for wider pickups such as a 7-string. We simply make an appropriately-sized shim to open out the template a bit more. Typically 7-string rings tend to be 10mm wider than their 6-string equivalents - give or take 0,5mm - which means we only need to make a 10mm wide shim. Cutting a shim from a stick of 10mm template stock in a fret slotting mitre box.... It's worth checking your pickup ring for its total width; this setup with a 10mm shim would expand the internal pickup cavity from 72mm to 82mm and the recesses from 87mm to 97mm. The 7-string pickup ring I have on hand is 99mm wide, so it would work with that one but you should confirm from your own measurements before committing to the wood! ....For The Entire Template Fundamentally, the sizes of the routs and your template should be designed from the pickup ring backwards. This is the only part that physically mounts to the body and covers the rout itself, so as long as the ring can be mounted, hides the rout and the pickup fits then it does the job. In theory the rout could be as large as you want it to be but ideally we should work the maximum sizes down to something more suited to the pickup itself. Removing only as much wood as is needed instead of as much as we can. We'd prefer to keep as much wood as possible, right? So let's look at a typical pickup ring and we'll see how I arrived at the dimensions of the basic template: Yep. Typical humbucker ring dimensions. Working backwards from this, we have about this much area that we can rout before we run into issues with the pickup mounting ring screws: Absolute maximum cavity area It's a pretty big chunk of wood to be dialling out of your guitar, especially when you compare it to a typical pickup: More than enough room to swing a humbucker If you want to alter your own template sizes to make a cavity that big, that's fine, overkill or not. The recesses either side should be narrow enough that the wood where the pickup ring mounting screws sit have enough strength left. The pickup ring measures 36,8mm/1,45" screw to screw. Bringing in the recesses at least 5mm from the centre of each screw location point is what I'd call a good minimum. This would make the recesses 26,8mm wide. For simplicity's sake, you'd round that down to 1" or 25mm. Simpler sizes makes cutting stock easier to manage. The same applies to the screws either side; their spacing is 81mm/3,19" giving us a reasonable maximum of 71mm/2,8"....calling that 70mm or 2-3/4" makes sense. The width of the pickup ring at 44,5mm rounds down nicely to 40mm or 1-5/8". Humbuckers are usually anything from 36-38mm in width. Unless you're working with a pickup with HUGE tabs (I've see some), the side recesses really don't have to be an inch wide. I mean, you could still stick with this value if you want, but most tabs are half inch at the most. 20mm allows for the corner radius of the cutter and means that the outer parts can be 10mm wide. Very very nice easy numbers! A recess width of 15mm centred on the main cavity's sides satisfies my internal need for symmetry, and brings the total width of the cavity up to 72 + 7,5 + 7,5 = 87mm. Fine for an 88,7mm wide ring. Drawing this out - a 72mm x 40mm central cavity and two 20mm x 15mm recesses (with 1/4" radii from the cutter) works out neatly. A wider/longer main body rout allows pickups with sharper corners to fit There's no substitute for taking a ruler and a pair of calipers to your pickup ring and pickup, then drawing it out after calculating your values in the same way. ....And Applying Them Let's use this to develop a template for a hypothetical mini humbucker: Now this should be relatively straightforward, however the radius of our cutters might mean the recesses have to be a little wider to allow for the tab corners. Let's have a look at the ring.... The pickup ring mounting screw locations are spaced 85mm x 25mm, so we can safely make the recesses 15mm wide to allow 5mm either side of the screws. Similarly, the maximum width of the main cavity can be 75mm. We'll be generous with the pickup cavity width, and let's call that a round 30mm. We'll call the tab recesses 15mm x 15mm. Let's see how those figures stacks up. Okay, that would definitely work as-is. Like the example with the humbucker, it might be able to be made smaller. Let's add in the cutter radius and see what happens.... Okay. The smaller size of this mini humbucker means that we need to cut a bit oversize because of the cutter's radius, otherwise things like the pickup corners and the tabs would clash with the rout. You could even make the case that the tab recesses could be drilled with a Forstner bit instead of being routed....! So this is how we could plan this out as a template set; pretty simple once you think it through! ----==---- Conclusion Making templates is about working ideas and methods into your personal trick bag. An extensible template that can be used in more than one situation is a powerful and productive thing to invent, otherwise we'd be making a new template for every last thing every single time. Routs that end up being hidden give us a bit more flexibility to bend dimensions in our favour to make the template simpler, or to streamline the rout itself. A system like this turns a humbucker rout into a three-minute job, sweat-free, making it worth its weight in gold to the busy luthier. ----==---- www.patreon.com/ProjectGuitar If you enjoyed and benefited from this article. become a Patron of ProjectGuitar.com and help us actively continue bring you even more articles, tutorials and product reviews like this, week-in week-out. We appreciate your feedback in the comments section, and we hope you enjoyed this tutorial as much as we did compiling it! This tutorial was made possible by ProjectGuitar.com's Patrons sirspens a2k Chris G KnightroExpress Stavromulabeta Andyjr1515 sdshirtman djobson101 ScottR Buter curtisa Prostheta 10pizza verhoevenc VanKirk rhoads56 Chip
Soapbar pickup routs seem simple in comparison to say, a humbucker or maybe a Tele bridge pickup rout. In actuality, they can be pretty difficult to nail. A soapbar cavity's outline is generally in full view instead of being hidden under a pickup ring, pickguard or the bridge; they need to be 100% perfect as any errors will be on show in the finished instrument. A basic soapbar rout consists of a simple rectangle conforming to the pickup with a small gap around the outline and radiused corners that follow those of the pickup case. This is bread and butter templating work for a router, however first we need to make a template, do so accurately and then look at how best to use it. Clean and neat; a Seymour Duncan MM-style pickup in a perfectly routed cavity. ----==---- Overview and Objectives This article will describe the fastest route from A to B using simple equipment and materials. Although not the most perfect or any kind of "gold standard", they are the easiest paths to the result and use techniques that can be built upon for more complex work. Expectations of accuracy rely only on your ability to check measure your work, practice and test on scrap before committing to a real workpiece. Anybody that can handle measuring tools, a drill and a router with reasonable confidence will get excellent results. We'll look at places where errors can creep in and how to spot problems before they bake themselves into your templates and your final work. Producing a basic rectangular routing template is easy, however the specifically-radiused corners smaller than our bearing-guided router cutters can manage makes this a little more involved. The approach we'll look at is to do this as two step process; use a drill to establish the corners, then rout the rest of the cavity with the template. A light pass with a chisel/file/sandpaper straightens up the difference between the routed and the drilled parts. Importantly, this relies on us having a template with square internal corners.... Two-stage approach - the red areas show the maximum reach of the router cutter, the green shows drilled corners. The minor discrepancy between the two can be seen in the flyout and is easily cleaned up. We will look at a slightly more complex single-pass method using guide bushings in a separate article in the Router Basics series to keep this tutorial on point. However, most of what we use here is transferable to that approach also and helps build your general working knowledge for templating of all kinds. What We Need Pencil A router with a small bearing-guided template cutter Lip and spur drill bits A sharp chisel Sheet stock suitable for templating (plywood, MDF, etc) cut into strips Double-sided tape Masking tape Wood glue Screws Credit Card (we're going to cut it up so you can't blow thousands on StewMac's overpriced tools ) Nothing that shouldn't already be on hand in your workshop! ----==---- The Template The primary method we'll describe deals with constructing a basic "fenced" template. This represents the rectangular negative space around the pickup, but most importantly it has square internal corners which we'll need later on. We'll be making a thicker template rather than something thin and flimsy, so dig around your scrap bins! What We Need The template needs four pieces of sheet stock good for templating (MDF, plywood, Masonite, dimensioned hard/softwood, etc). In this example, I'll be using 16mm MDF since it is easy to find thick scraps. Each piece needs to have two clean flat sides at 90° to each other. If you are wanting to make a permanent template, the pieces should be narrow enough that they can be drilled/screwed together. A good width for these strips is 1-1/2" to 2" wide (I used 40mm) then cut down into shorter lengths with a mitre saw, table saw, etc. Two long (roughly 8"/20cm) and two shorter pieces (4"/10cm) work for almost any size pickup. Larger pieces can be stuck directly to the workpiece to make a temporary template using double-stick tape and disassembled after use, however you won't get a test run! Ideal sizes for making a fenced template Using scrap pieces works fine also, as long as each one has two straight edges with 90° corners The thickness of the template stock depends on the length of your router cutter. If your cutter is too long and/or your template too thin the initial routing pass will be extremely heavy, which can produce poor cut quality and isn't safe. For handheld work, a good guideline is that the template should be just equal to or a little thicker than your cutter is long. My smallest template cutter has a cutting depth of 15mm, making 16mm MDF a satisfactory match. My go-to cutters - 19mm⌀ x 25mm and 12mm⌀ x 15mm What Is A Fenced Template? I'm glad you asked that. The concept of a fenced outline is simple; it is an arrangement of clean-edged template stock around the part being templated. A rectangle is extremely simple to fence since the four parts can be moved around to fit snugly against the pickup and against each other: Basic fence arrangement It becomes immediately obvious how important it is that the fence parts have those two straight edges at 90° to each other! If your fence joins do not close up cleanly, or straightening one part throws another out of alignment, check your pieces (and perhaps the pickup) with a set square for straightness and perpendicularity (that spellchecks, so hey). Any gaps caused by poorly-fitting parts will be apparent in the end result. When correctly made, this fence will represent a razor-tight copy of the part's outline. Note: most soapbar pickup cases will have a draft angle on the side walls; these are a design byproduct of the moulding process which allows the part to de-mould easier. The fence parts need to be aligned with the lower edge to make a correctly-sized template! click to enlarge Easing The Outline A tight copy of the pickup outline sounds good in theory, however it will not leave breathing room for any sort of basic fit or any finish. A pickup cavity created from template like this will just be too tight in practice. The fence arrangement described above needs easing by shimming out the pickup slightly so that the final fit is more appropriate for the end use. 2 layers of masking tape applied to all four edges adds a hair of width: enough for a simple non-building oil/wax finish, or in fact no finish at all. This is the minimum that should be considered for any cavity made from a fence, and equates to a border (in the case of 3M blue Scotch tape) of around 11mil/0,3mm or a sum easing of 22mil/0,6mm on the length and width. 3-4 layers is about the maximum before tape becomes less consistent in how much size it adds. This is enough to allow for a thin layer of conductive paint or a thin non-built layer of Tru-Oil (or similar) within the cavity. Thicker built finishes need more easing than tape can reliably provide. 3 layers of blue Scotch tape increased the size from 89,3 x 38,5mm to 89,8 x 39mm Note: the casing did not measure out as 3,5" x 1,5" (88,9mm x 38,1mm) as per the datasheet! Heavier easing can be achieved through the use of veneer scraps, pieces of a chopped up credit card (thickness is exactly 0,03" or 0,76mm) or other strong thin material of known thickness. Simply cut two pieces; one slightly shorter than the width of the pickup and one shorter than the length. Stick them to the inside face of your fence with a glue stick or something else you can remove later on. If you want a lot of easing, it's just as simple to shim both sides or double up the material. If you've ever shopped at StewMac, you should have plenty of these maxed out, ready to cut up If you have access to tooling accurate enough to produce a stand-in part for the pickup, this is an excellent option. This can be cut to a specific size to add an exact amount of easing that you want. The surrogate part was cut to allow a specific amount on the length and width A fenced template using a surrogate part If you dimensioned all of your template stock to the same width as the pickup surrogate part, this arrangement is also possible! click to enlarge Making The Template If you are making a temporary template direct to your workpiece, you can simply stick the parts straight to it using double-sided tape and skip this section. However, most people will want to make a template they can re-use and that can be tested on scrap. After lining up your fence parts around the pickup and easing as you think most appropriate, mark out where the mating faces are located. These visually help us to put glue only where it's needed, saving work cleaning the template later. Better than trying to remember which bit goes where with glue running around! Apply a little glue to the mating faces on all four joints and reassemble. Only clamp parts finger tight or use a little masking tape over the joints to keep them secure; we're not expecting a strong bond here (especially with MDF); just enough that the parts stay in place for the next stage. Check that the parts are still snug to the pickup. Glue works as a lubricant when wet, and any pressure clamping this up can cause parts to skate around. Again, finger tight and check carefully because errors here will come out in every cavity this template cuts. Looking good! Once the template is stable, gently remove any clamps and the pickup. Drill pilot holes to full depth for four screws. MDF is extremely weak and splits when you force screws into it. I chose to use a 4,0mm pilot to compensate for the 5,0mm threading. Countersinking is a nice touch but only necessary if you want to locate the screw heads below the surface. Clamping the MDF between two pieces of wood during screwing also helps prevent splitting. Whichever material you use, pilot holes are essential. click to enlarge Result - a quick, easy and accurate router copy template ready to be cleaned up. click to enlarge Using stock in this method to create fenced templates is quick and economical with no mess. Keeping a bunch of thin dimensioned strips on hand specifically for template making means you can quickly fabricate them to whatever size you require before you can say, "Titebond setting up time". ----==---- Making A Cavity Using The Template As discussed earlier, we will be carrying this out in two main stages. Firstly, we place the template and use the internal corners to establish the corner radius through drilling. Secondly, we use our router to cut the rest of the cavity. Lastly, the difference between the drilled corners and the routed cavity are cleaned up. I guess that sounds like three, but it's not really. Can we agree on two? Great. What We Need Attaching the template to the workpiece (preferably a test piece first!) requires that it is either clamped down or attached with double-stick tape. We also need a little masking tape. For drilling the holes, a lip and spur bit (with a sharp well-centred point) plus either a pillar drill or hand drill. For routing, a short bearing guided template cutter either in a hand router. Four pieces of double-stick tape attached to the underside of the template is plenty Briefly clamping down a template causes the double-stick tape to adhere very strongly! A little goes a long way. Drilling The Corners Most soapbars have corner radii which are smaller than our typical bearing-guided router bits, so instead we need to let our drills do the work for us. Choosing the size bears a second of thought. In the example used for this tutorial - an EMG-35 pickup - the corner radius is about 1/8" (3,175mm). We can either copy this by using a 1/4" diameter drill bit, or we can increase it in relation to how much we eased the outline earlier. EMG-35 size specifications The plastic card I used to shim the pickup on all four sides was exactly 0,03" (0,76mm) thick. Adding this to the corner radius and doubling that produces the "ideal" size of drill I should be using; 0,31" of which the closest Imperial size is 5/16". The closest common Metric size is 8,0mm. Ideally we should try to round down rather than round up; a larger drill bit diameter brings the corners closer in to the pickup. Alternatively, you can just use the same corner radius as the pickup itself. I'll demonstrate a number of sizes so we can see how they compare visually in the finished example. Firstly, we need to protect the template from the drill. A small piece of masking tape does this well. click to enlarge Next, place the drill bit square into the corner. This is far easier with thicker templates. click to enlarge Tapping the drill bit with a small hammer or similar creates a strong location mark for the drilling itself. click to enlarge The finished hole. Clean and located perfectly. Over time this process can damage the template however, leading to less accurate corner location. Still, a small price to pay and making new templates once in a while is simple. click to enlarge Routing The Cavity The router was fitted with a 12mm diameter 15mm deep cutter to make an initial pass a few mm deep. The setup was checked to ensure that the bearing was contacting the template. click to enlarge After the first pass, we can immediately see the discrepancy between the drilled corners and the routed area. click to enlarge A second pass brought this test cavity to a reasonable depth. Now is a good time to shave those small corner discrepancies away using a chisel held flat against the template..... click to enlarge Removing the template shows the differences in corner radii. click to enlarge Let's have a closer look at those. 5/16" - the size calculated to match that of the pickup corner radius plus the offset from shimming. It might look overly large to some, but it clearly conforms to the radius when you inspect it in person. click to enlarge 7,0mm - the nearest Metric size up from the pickup corner radius. This looks fine too. It's difficult to capture a good shot of these thanks to that draft angle making things look confusing from different viewpoints.... click to enlarge 1/4" - identical size to the 1/8" corner radius. That also looks perfect in spite of there being no size compensation! click to enlarge Improving The Templates As it stands, the template is extremely usable and repeatable in spite of its simple construction. Thicker sheet stock definitely improves accuracy during the corner drilling procedure however. I found that 16mm (5/8") stock is about the minimum before drill alignment becomes tricky. A useful addition to the templates is alignment marking. These can be done either as simple pencil lines or location holes drilled through to provide highly-accurate visual alignment reference. Firstly, flip your template over so that the underside is on top, then mark out the centrelines accurately. Check and double-check these from both sides using as many methods as you can! Centre lines marked out on the underside of the template Place the template on a piece of scrap, centrepunch and then drill all holes through cleanly. Drilling from the underside ensures that if the drill wanders away from the centre during the cut (I used a cordless drill) then the underside is guaranteed to be correct, and this is what matters. Note: Ensure that any screws driven into the template don't lay in the path of your drill! If necessary, withdraw them, clip them shy and re-insert them.... Holes drilled through the template Next, flip the template right-side up. Using a countersink, ream out the holes until the tip of the countersink touches the scrap board underneath. Countersinks tend to "drive" suddenly, and then stop advancing. Clean out the cutter and then give it another try to advance deeper. This took me two passes each. This is what the finished template alignment marks should look like, and how it works. ----==---- www.patreon.com/ProjectGuitar If you enjoyed and benefited from this article. become a Patron of ProjectGuitar.com and help us actively continue bring you even more articles, tutorials and product reviews like this, week-in week-out. We appreciate your feedback in the comments section, and we hope you enjoyed this tutorial! Thanks to ProjectGuitar.com's Patrons sirspens a2k Chris G KnightroExpress Stavromulabeta Andyjr1515 sdshirtman djobson101 ScottR Buter curtisa Prostheta 10pizza verhoevenc VanKirk rhoads56 Chip