cad The Lancaster

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At this point you want to be deciding on how you prefer your neck taper. The distance each string is from the edge of the neck differs at the nut from the top frets. I tend to use 3.5mm as a rule on guitars. You can go closer, however you risk strings falling off the edge of the fret depending on your playing and vibrato style! 3.0mm is best for most players, however since this guitar has a trem and my personal playing style involves light circular vibrato I like that extra mm.

Using the Select tool, select any of the small line guides we have been making and Edit > Copy it. Edit > Paste it near to the 24th fret. Using the Intersection snap, drop it where the low E intersects with the 24th fret guide. Paste in another and drop it where the high E intersects with the 24th fret also:

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Select both of these lines by dragging a box around them:

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Note the "Size Y" in the Inspector Bar - 49,1mm. Adding 7mm to this produces 56,1mm. I'll go with "56mm @ 24th fret". Change the value in Size Y to 56mm:

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Create a new layer called "Neck" with a Z order of 5 and whatever colour you choose:

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Now, select the Line tool and set the active drawing layer as "Neck". Change the snap mode to Intersection. Now draw a line from the intersection of the nut guide line to where the 24th fret guide line intersects with the two lines we have just drawn:

From here:

 

To here:

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Repeat for the other side and we have:

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When designing your own instrument, changing these values is no big deal as long as you have a solid methodology on how and why to do it. Hopefully this is explaining the decision-making process adequately!

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For non-geometric body designs, I prefer paper. I simply draw out a centreline and sketch from there using a pencil and rubber. Nothing special or accurate but simpler for proportioning, etc. I scanned this in and imported it to TurboCAD, placing the body where I felt it would work best.

This kind of sketching work is what you learn in school. That is, idling drawing guitars whilst your lecturer yaps on about structured systems analysis and design methodology. Not in art class. That when you raid the textiles cabinet for nylon stocking to stretch over your head. Priorities.

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Imported into TurboCAD; it doesn't handle bitmaps well so imported images are useful only for rough guides. I placed the body along the centreline and made a sensible balance between the top horn's balance over the 12th fret (not a hard and fast rule) and with reasonable fret access. The body was scaled to reasonable proportions by eye which ended up very marginally narrower and shorter than a Strat. I can live with that. If it looks odd I can adjust that later.

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Using the Bezier tool I picked points at concave and convex apices. Experience from having done this a lot taught me that some specific areas benefit from an additional point to give more control over the curvature and rate of change. In general, a smooth outline like a Strat ideally needs as few as possible otherwise redundant points can disrupt smooth curve transitioning. After placing the points, nodes were adjusted to bring the curve into line over the scan. Horn ends tend to be the most difficult as they can easily look clubby, wonky or badly-proportioned.

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Viola.

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Earlier, I decided to ditch the top two frets. In hindsight, I think they can stay.

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Right! Let's pick this one up for a couple of hours then and see where it takes us. A few design "choices" have been made after letting her sink in. First, let's get ourselves some appropriate music chooching.

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I decided to balance off the project scope a little bit since the design aim of having an OFR (or any good trem) in there is a significant money investment. Keeping it simple and straight down the line feels more right to me anyway, especially given my history of blocking off trems when nobody is looking.

On that basis, a simple hardtail (your 7-string got me thinking this way, @psikoT) or maybe a TOM arrangement would be less burdensome on the old beer tokens. I like the idea of a simpler hardware anyway as a full OFR or other tremolo is an imposing bit of modern machinery for what is essentially something with 70yr-old throwback looks.

The controls are provisionally going to be something inspired by this photo of an Avro Lancaster console specifically the black toggles and plate at the top right. If I can locate small-but-chunky switches as 1x SPST On-Off, 1x DPDT On-On and 1x SPDT On-On-On we're in business for neck coil tap, phase and humbucker three-way switching. I'm tempted to make it active just to get that cool "boost coil switch" plate in there! Slotted screws should be simple, but you know what chances are like.

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Having that ticking over in my mind solved the decision-making for the bridge. The destined finish for the guitar will be a part disruptive earth/green camo top and night camo lower. I have a little bit of personal distaste for the civilian casualties caused by the destruction of the Möhne dam, so I won't be marking this one up with the AJ/J and roundel but something different.

I thought long and hard about the choice of fingerboard, fret markings, etc. and decided that the best tie-in would be a matt-black wood such as Ebony (or a black composite) plus inset chemically-blackened rivet heads as markers. The alternative here would be a painted fingerboard to match the body. The jury is still out. The overall paint scheme will be a more matte than gloss. I might actually paint the bridge and pickups to match....

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Interesting. I seem to have a few ABR-1 bridge clones hanging around the old bits box. One of the black ones has a little brown (what I think is) rust in the saddleways which is perfect! That means we're either going to have to design in a neck angle or recess her. I'll think about this a little.

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Incorporating an ABR-1 type bridge into the mix does alter something very specific, and that's the string spacing. This unit measures a 51,5mm string spread whilst earlier, I dialled in a 53,5mm spread. No big deal.

Using the Select tool, I picked up all six string guides. This can be done by either dragging a box around them, or picked one by one creating a multiple selection holding down Shift.

 

....note the Y extent is 53,5mm in the Inspector Bar. Change that to 51,5mm.

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Uh-oh! The strings no longer terminate in the right places. That needs fixing then. Introducing the (Node) Edit Tool:

 

Using this tool allows us to edit the nodes that make up individual objects rather than the entire object. In this case the lines that represent string paths. Change the snap mode from (in the photo above) Vertex and Intersection to just Intersection, then pick each string....

 

Then pick each node/vertex (blue square) and drop it onto the intersection of the guides. Note how the snap mode works:

 

Do this for all six:

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A little appraisal on the "fitness for purpose" of this drawing. If this were being made for illustrative purposes, one might actually draw in the ABR-1 bridge itself. Since this serves no useful purpose in its entirety, it can simply be obviated. It's just cosmetic fluff really. I thought that it might be useful to see the process however, as it allows you to see me working in TurboCAD in realtime.

Let me record that sucker....

[psikoT]

I've found hardtail bridges a lil bit more ergonomic than TOMs while playing, due to the neck angle... as for the controls, maybe you can get some inspiration from Hutchinson guitar concepts (http://www.hutchinsonguitars.com/).

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Okay, this was a pretty quick and dirty affair. First time recording a live screencap whilst working...

The bridge itself measures 11mm x 84mm. These values are not so important, or at least not as important as the saddle geometry and the mounting! I started by creating a new Bridge layer. A rectangle measuring 11mm x 84 was added in, plus two circles 11mm in diameter. These were positioned relative to the rectangle and mathematically transformed with a little trimming to create a round-ended object. At that point they were a pair of lines (all that remained of the rectangle) plus two arcs (remains of the circles). The hatching procedure filled this outline with a single solid object. This was important as you'll see later.

The pause was me measuring the saddle keyways with calipers. I drew one in as a rectangle and calculated the distance centre to centre (string spread divided by five since they're centred). One was copied downwards then the two pairs to make six. Those were then moved to the centre of the hatched object. This would not work if they were separate lines/arcs!

Rough saddles were drawn up, added to the keyways so we can represent the offset they add in. Three are reversed on the saddle side as usual.

Next are the post holes. I had a brainfart here so I messed up a couple of calculations. It is what it is. I popped the calipers into both post holes and measured the closest internal points, so I needed to work out this plus the post diameter to find what they are centre to centre. I got there after kicking myself.

ABR-1s are finicky beasts. They really don't provide much intonation room. The usual method of giving yourself a little more breathing room is to angle the bridge slightly so that the thicker strung side lays further back from the "perfect" bridge witness point. 3° turns out to be a good amount (forgive the farting about with values as I was thinking of doing a full in-video annotation) plus a little to offset it back.

The values were a little wrong so I adjusted it back in around the 11:07 mark.

We're left with about 4,5mm - 11mm of adjustment on the bass side and about 1mm - 7,5mm on the treble side. The angle does reduce the string spacing marginally but it's better than crap intonation. I might fiddlefart around with the positioning a little in the meantime. Still, you can see where this was going I hope.

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I've found hardtail bridges a lil bit more ergonomic than TOMs while playing, due to the neck angle... as for the controls, maybe you can get some inspiration from Hutchinson guitar concepts (

http://www.hutchinsonguitars.com/).

 

I'm trying to use up as much stuff as is already on hand. Dropping a couple dozen Euros on a bridge is a couple dozen Euros less on a DSLR to start shooting tutorial vids! I could recess it for ergonomics I guess, but I like making it a little less "basic modified Strat". That's what these things always end up like, right?

Hutchinson's guitars are awesome. Really nice original accoutrements!

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Okay, so after that little adventure we're left with this:

 

I wondered whether to bring in the sides of the neck since I adjusted in the string spread from the new bridge inclusion. It hardly affected it, so I'm happy to leave the neck as-is.

Let's finish off the fingerboard, shall we? For clarity, I turned off the String layer (eye icon in the Design Director). We can see here that the 24th fret is accessible enough. Certainly not the easiest, but not bad either. I think that I'll stick with a flat-ended fingerboard. This was simple added in by using the Parallel line tool:

 

...then selecting the active layer as "Neck", clicking on the 24th fret guide and typing either "7mm" or "-7mm" in the Offset depending on which way the line wants to go (cursor thing), then pressing Enter:

 

 

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Ah, I'm going to make another change. Let's have a zero fret. There's no locking nut to complicate things now. This done by doing more or less the same thing at the headstock end. I rubber stamped a fret guide across first:

 

....turned off the Guides layer for clarity and did another Parallel line to that new Fret Guide, but 3mm instead of 7mm: