ESP M-II type "Invaders" Superstrat

[Prostheta]

Forearm contour:

[Prostheta]

Heel angling:

[Prostheta]

The neck blanks winging their way to me from Germany measure 870 x 100 x 31 which is more than adequate for two necks. The plan is to thickness these down to the 25mm required for the neck (based on the heel depth) and reduce the part scarfed to the headstock to enough that it supports a volute. At the very least I'll do a volute on one of these necks, the Mirage having had one originally. The choice of to-volute or not-to-volute affects the mounting of the locking nut slightly, mostly in planning to get a neat crisp pair of recessed mounting holes at the back if I go that route.

100mm isn't wide enough to produce a headstock scarf without glueing on at least one wing. For the Invaders build, the neck blank will be laminated with 2x 5,5mm Bubinga laminates. Losses from the table saw and rejointing will lose maybe 9mm so we're more or less still at 100mm either way. The central Maple laminate will be lightly tapered in proportion to the neck's overall taper which I'll work out at a later stage. This will again lose a little from the width at the headstock end. The Bubinga I have isn't long enough to support lamination through the entire blank, so these will stop at the headstock with that being plain Maple.

In other news (apologies if this is slightly OT) I was heartbroken when I found photos of my old ESP from the auction site. Firstly, it was sold WAY undervalue and I would have picked her back up for several times that had I known. Secondly, she's been beaten and damaged. I just hope she's found a better home than a few hundred pounds might indicate.

 

[Prostheta]

Looking at the construction of the original, the neck was made from 3x pieces of 25mm Maple. I've always admired Japanese manufacture, and their way of building in both economy and robust construction principles just floors me every time. This neck could easily have been one piece of QS or FS Maple, however it's a mixture of both with growth ring symmetry being the principle at play. One piece of QS in the centre for geometric stability (not stiffness, that's an oft-overused myth) with random sawn either side. That's maximum yield from stock with dialled-in stability. Love it.

What always got me about that Mirage was the lack of introduced neck angle and the flat-mounting Floyd. This resulted in a very deep heel and slightly higher than usual fingerboard to body separation. It was the transition between the Horizon model (1988 onwards) and the lawsuit Mirage (Jackson-style headstock till 87). To date it's been a unique example, and I would say that the odd geometry features would place it as a concept or prototype.

By comparison, the Invaders model is a much more quantifiable thing. The '87 "The Mirage" examples are pretty accessible if you've got four g's kicking around. They carry (to me, anyway) a lot more mojo than the Soloists or other typical superstrats of the time.

A minor detail in common between my old ESP and several others that I have photos of in my archive....the headstock has a very well-eased edge from the face to the binding. Not quite rounded, but not sharp like modern off-the-shelf ESPs. The neck is also nicely rounded from the fingerboard to the binding. Again, not sharp at all. As you'd expect, the factory fretwork was second to none. These are all small yet important details that make the difference between a soulless machine-stamped axe and an instrument that is crafted and finished to perfection by human hand and eye. Wood and wire is pretty similar in most guitars, but it takes craft to make those feel like a million dollars.

[Prostheta]

Lamination strategy. This can be done any number of ways from the most simple - parallel laminations - to the most complex multiple laminations. I've elected to taper my central laminate and have the outer laminates follow that. The blank I'm using is relatively-plain quartersawn Maple with minimal runout and good apparent growth ring radii. This should be plenty stable as it stands, but once that Bubinga is added it'll be a far better neck. It's the sort of wood that adds clarity when used in balance with overly-warm or bright-sounding woods. I've found that I prefer Bubinga laminated with Maple and Wenge with "slower" woods like Sapele or genuine Mahogany. Even though it isn't a world of difference, I've always had more pleasing results with woods used in combination than on their own.

To calculate the taper, I look at my top-down neck drawing and create extension lines to an intersection point.

 

At the heel end, I draw out a box of a specific height corresponding to how wide the central laminate needs to be at that point. Let's start at what, 16mm? Then, two lines are drawn from the back of the heel where the box crosses out to the far intersection point.

 

Then two boxes perpendicular to these lines are extended out the same width as the laminates (4,5mm each).

 

Ain't tea bag. Let's try 12mm separation for size.

 

16mm seems like it will present better over a thinner flatter neck than the narrower spacing which would likely work on a rounder and more traditional profile. This is something I haven't discussed or even put much consideration into at this stage. I think I'll go for the wider 16mm spacing and see what happens when I preview it over the profiling drawn up in the 3D model.

[Prostheta]

That brings us here. Looks good even though the volute isn't symmetrical.

'

<edit: and the laminations aren't going all the way through to the headstock scarf>

[mistermikev]

53 minutes ago, Prostheta said:

That brings us here. Looks good even though the volute isn't symmetrical.

someday... I wish to be able to render things like that.  just looks wonderful.  also, that mirage - what a lovely guitar.  seeing that boo boo on the headstock just makes me want to fix it.  

that neck profile looks really flat and wide.  I like all types, but appreciate very much variants of the jem wizard 1 which looks pretty similar to that.  maybe a hair less U.  bet she'll play like greased lightening.

[Prostheta]

Taking this into the wood presents a few considerations beyond dialing in a taper accurately. The blank should ideally have a lower reference edge for the CNC that is absolutely parallel to the centreline. This part is the trick. The easiest way of managing this would be to modify the front referencing face of the blank where the pneumatic pillar stops land. Changing the entire reference edge is far from ideal. The modification can be done by either adding material to the reference edge where the rightmost pillar references as a "permanent shim" or removing material from where the leftmost pillar references.

 

[Prostheta]

9 minutes ago, mistermikev said:

someday... I wish to be able to render things like that.  just looks wonderful.  also, that mirage - what a lovely guitar.  seeing that boo boo on the headstock just makes me want to fix it.  

that neck profile looks really flat and wide.  I like all types, but appreciate very much variants of the jem wizard 1 which looks pretty similar to that.  maybe a hair less U.  bet she'll play like greased lightening.

Thanks man. I actually reached out to the auctioneers to see if they might be able to contact the new owner or the seller. I'd dearly love to have that guitar back.

[mistermikev]

8 minutes ago, Prostheta said:

Thanks man. I actually reached out to the auctioneers to see if they might be able to contact the new owner or the seller. I'd dearly love to have that guitar back.

not a lot of us get a 2nd chance at "the one that got away" so... fingers crossed for you.

[Prostheta]

I need to remember how I did the binding. This isn't important since the CNC doesn't need to know most of this info. I also fixed the poor outline shape, which I've noticed a lot of people get wrong including sellers of templates and drawings....yikes....

click to embiggen

[Prostheta]

It also looks good in cream-white....muuuurrgghhhhhh

[Prostheta]

Alrighty then. Let's look at how I've marked out the neck for sorting the scarf and laminations. Excuse the mess, do come in:

 

The entire Maple blank measures just over 870mm in length and about 107mm in width at 26mm thick. I marked it out for maximum yield, or at least minimum chance of screwing up. In CAD I measured out the lengths of each piece rather than marking out a 13deg angle. Measuring that way is much more accurate over short distances and acute angles. The two pieces were marked out from opposite ends with 25mm having been added in to the headstock length (this rapidly loses length with any scarf glueup error) and 10mm on the neck length. Once these lines are established, they're taken over the edges, joined together and then a midpoint between the two draw up. That way, I can laminate the neck part with a good degree of excess (plus that 10mm) and the same with the headstock. Scarfing a neck with tight tolerance is prone to issues, and for the sake of a few Euros of additional length on the blank you can easily build in a bit of insurance. I'm unsure how I'm going to cut that 13deg, however I'm thinking it will be a combination of a table saw plus a 13deg-edged scrap of MDF or plywood. It doesn't need to be accurate as the whole thing will be cleaned up further down the line.

I'll probably take the neck part from one side of that 107mm piece (or however it ends up after lamination) as the grain is almost perfectly vertical on one side, maybe a few degree off on the other. The waste can easily be used to fill out the headstock tips, however I want to try and keep as much width on the neck as possible so the CNC has plenty of excess to grab. Offsetting the vacuum consoles along the width reduces any sort of twisting (this shouldn't happen anyway) and increases flat referencing.

[Muzz]

So many inspirational guitars have come from Japan, the white with black and gold design looks especially awesome.

[Prostheta]

I know, I'm quite liking it as well. I have to see if I can find that particular Subaru paint chip that I found which is white but with a subtle gold fleck in the micas. It'll have to be a project for later in the game, however once the process for this guitar is down pat, it'll be pretty simple to make several without that much effort. Most of it to this point has been refining the details that have bothered me, testing this and that, etc.

[Prostheta]

Speaking of which, here's today's work so far.

13deg scarfing jig (I decided to stay with 13deg as it has a different "reveal" of the truss rod access cavity than 11deg) set up on the table saw. The pieces were cut at 40mm, 80mm and finally 120mm blade height. Being a rip saw, the surface finish is not what I'd call adequate for glueup straight from parting like this. A tap with the hammer on the back of the clamped piece allows for a slow steady pass to be taken at a fraction of a mm which is perhaps okay for glueup. If it's not airtight, it can be better.

 

 

I didn't get photos of this process, however the neck portion of this blankk (I made three) was split into 30mm, 20mm and about 50mm. I cleaned up each part with a thickness planer to a mm under those sizes. The central laminate was tapered on the jointer using the same sort of technique I've described previously years back. Set the jointer cutting depth to half of the difference from one end to the other, cut the piece halfway from the desired thin end first and stop when the cutter head's top dead centre is at the halfway mark. Reverse the piece back to front and tip the front end up, pivoting off that halfway cut. Cut this over the jointer to achieve the required taper differential, and take finish passes until the whole piece is at the right final sizing.

In my case it was 16mm to 11mm, so I set the jointer at (16-11)/2 or 2,5mm depth of cut. Those two passes left the part about 19mm at the body end (as it came out of the thickness planer) and 14mm at the headstock end. The process wasn't as perfect as I've described it here, so the finish passes were a combination of fine tuning and final sizing. Generally this works quite well, but I did set myself very specific dimensions to hit, and I'd be disappointed in myself if I did half a job....

[Prostheta]

First order of business. All parts were brushed clean of dust and then wiped with acetone. This isn't a good idea with oily woods like Padauk unless you want to end up with pink Maple. The Bubinga benefits from a wipe, nonetheless. Not a soaking! Then, the layup is flipped and taped from the back. Clamps lightly cinch everything together as a pack.

 

I removed the clamps and smoothed the tape down to try and get everything as flat as possible on the lower surface. With a good tape, the layup can be opened like a book between the individual mating surfaces for glue to be added. Titebond Original is the best benchtop glue here. Titebond II and III are inappropriate as they're designed to be more flexible to withstand wet environments.

A length of plywood serves as a flat base to clamp everything up. The tape stops glue getting out. Two cauls and vertical clamps hold the pack in line whilst the rest of the clamps keep everything silly tight. Let's estimate numbers! Well, that's roughly an inch of thickness over maybe 36" of length, so 36 square inches. Each of the large clamp delivers about 1000-1250PSI, small clamps maybe 250-500. Six clamps of varying size, let's simplify and call them all equal size. So maybe 5000-6000PSI across the whole layup, divided by 36. That's what, about 120-140PSI? It's a little under the 200-250 that I try and aim for, but perfectly adequate. 7-8 clamps would have been better (200-220PSI) but things get crowded very quickly.

[Prostheta]

Also, I cut through the first fingerboard to see how deeply the inlays worked with the epoxy. Not very deep at all as it happens. Air gets trapped at the bottom of the pockets, especially the single-pixel things like the alien shots and asplody bit. Hmm.

[Prostheta]

Whilst not attached to this specific project, I made up a second 13deg scarfed neck blank of Maple and Wengé.

Same as the Invaders neck blank, this is current 26mm thick on both pieces with the same basic oversize dimensions.

 

The way I stop pieces sliding is to clamp the layup dry, drill a 2mm pilot hole through both pieces, open out the top to 3/4mm depending on the screw thread size, then drive a screw through into the rear component. All of these are outside of the neck/headstock outline of course. I do two from the rear and two from the top. They don't provide any sort of clamping pressure, simply locating. <edited for clarity>

As I explained earlier about the quality of cut off the table saw, a combination of the high positive tooth angle of a rip blade and the tool pressure deflecting an open skim cut leaves this sort of machining marks. The mating surface underneath was given a sub-mm slow pass which is adequate in a well-supported cut.

 

The leading edge here looks dry, however it is not. This seam is outside of the workpiece, and the entire face of the body component was evenly coated with Titebond Original. Squeezeout is seen as a gold standard of sorts, and in many ways its presence (given an evenly wetted coating) shows good clamping pressure and all that. If you know the quality of your glueing surfaces, clamping arrangement, etc. then it isn't always an absolutely necessary sign, I prefer less mess, so spend more time ensuring the layup will be good and establishing which clamping arrangement to use whilst dry, In this case I used two small clamps on the outer edges and two honking clamps across the centre. The parts can be marginally massaged into alignment if things aren't 100% correct through hammer taps whilst the two small clamps are holding the layup.

[Prostheta]

It's unlikely that anybody can help answer this question better than Google has provided so far, however I am looking for Martin-style U-channel truss rods within Europe. Generally these'll be listed as "Martin style truss rod", "Gotoh truss rod", "Hosco", etc. €16 for a 430mm rod seems about the right price, with a lot of places inflating that cost by anything up to 100%. I really dislike Stewmac's Hot Rods (way too deep), the cheapy "welded with a sledgehammer" Chinesium blue-plastic rods, and don't want to order from outside of the EU for shipping, import and VAT reasons.

I think Guitars and Woods are going to be the winner here. By far the best deal all around.
https://guitarsandwoods.com/materials-and-supplies/truss-rod-and-covers/aluminum-truss-rod-410-guitar-65994988.html
€16 is a great deal. Shame I can't find any other items to pick up from there for this project....

[Prostheta]

So now, we're here.

After throwing the neck part of the blank over the jointer and through the thickness planer, I drew a line that is parallel to the centreline, close to the lower reference edge of the neck. This is the reference edge we're use from hereonout. With all of the cutting, tapering and laminating, that reference edge is absolutely needed to know where anything is at any time. The edge was tuned on the jointer using the same part cut/flip/tip method as doing the taper until the clean cut edge was parallel to the drawn line. I might fine tune this more after double-checking everything, but for the moment it is good enough that the scarf will be out hundredths of a degree at most. If that edge were out of parallel by the 4-5mm it was initially, that angle would be significant enough to be visible.

 

Back onto the table saw with the 13deg scarfing jig. This time I swapped out the blade to a 400mm combination/crosscut. The riving knife is further back than I would normally set it myself (typical in a workplace....) but not an immediate concern.

 

The first cut takes off the extra length from the Bubinga and roughly surfaces the scarf.

 

A tap on the back end of the blank with a hammer advances it a fraction of a mm into the cut, allowing a clean skim to be taken. This is perfect for glueing with no extra work needed.

[Prostheta]

The question now is where to located the headstock scarf component of the neck blank. The headstock shape is significantly offset and has a width greater than that of the Maple being used. Placing it dead centre would require additional "wing tip" material to be glued either side. So one option is to line up the headstock so that the lower part of the reverse headstock is a single part, requiring the very end tip to be supplemented with a Maple cutoff. The other is the reverse of this.

 

Drawing this out, we can see that with a 107mm wide main headstock piece we need a 12,1mm wing glueing either side. In my opinion, it would be better disguised below the 1st string's tuner. Wood chosen with equal growth ring alignment and from close proximity should be close to invisible, or at least harmonious. I recall that my old Mirage had a striking contrast between two adjacent pieces....the only fault that you could really pick, other than those MIDI pickup holes and the banged-up headstock....

 

So this is the sort of arrangement we're looking at. If I mark the headstock component of the neck less than 38,4mm from the centre then we're golden. I'll make up the missing material from wood immediately adjacent, testing for which direction works best for colour and grain appearance.

[Prostheta]

Marked out on the components. I only allowed a few mm grace for the tip, so I really need to either add a bit more or do some double-double-checking.

 

Dry fitting with a small clamp. If I move the headstock component a mm or two upwards and avoid that small angle, this should succeed nicely.

 

[Prostheta]

Same procedure as always. Once dry fitted and secured, drill 2mm pilot holes through the edges from one piece to the next. Open out the hole on the upmost piece to 3mm so the screw doesn't grab, but pulls the lower piece upwards.

 

Given how close these screws are to the perimeter, I would have preferred to use small panheads or maybe add washers so the countersink profile doesn't encourage splitting. I don't have either immediately on hand, but these don't need torquing down. Just enough for location purposes.

[Prostheta]