I’m currently planning my next guitar projects for 2022, and finishing off the Acacia Concert Ukulele, honest!
The instruments I have made this century, indeed this decade have been firstly a kit, without any drawings, followed by a pair of ukuleles built solely from drawings.
What I have learned as a woodworker from making them, is that there are very few right angles that you can register from in an acoustic instrument like a guitar or ukulele. So I have given the matter some thought, and done some online research and so have learned how to use a drawing program so I can forward some files to the laser cutter man, Dave Neale of this forum, to fabricate some templates for me from acrylic.
I plan to make at least two instruments during the coming year. Two, I hear you ask. Why two? Well, why not? While some of my contemporaries spend their money on cruises, classic cars or Harley Davidsons, I spend some of mine on making musical instruments, and the tools and machines to make them.
Now, if I hand cut and hand carved two instruments from the same set of plans like I did with the ukuleles, then I would end up with two nice looking instruments, but their dimensions and even their shapes would differ. I’m not good enough to consistently create pieces of work the same every time.
This time I’ve chosen a Taylor T-910 Dreadnought 6 String Guitar for the design. Unlike the ukuleles for which not only were the plans transferred online, but if you wanted to pay, then 2D CAD files were also available, the supplier of these plans only supplied them in hard copy on 3 A0 sheets. So I’ve had to have them scanned and then ‘hand draw’ electronically the elements of the drawings to convert them into dxf files in order for Dave’s laser machine to zap them.
That’s a whole other ball game. I tried Sketchup, of which I had got quite proficient during my workshop build, but they wanted something like a months pension for the version to export dxf files. I then tried LibreCad. I have the LibreOffice suite, so I thought I’d I’d get on with that, but either my Mac Mini or me didn’t get on with it and I eventually turned to Inkscape.
I’m doing OK. It’s a steep learning curve for a pensioner like me, but they say learn a new language or a musical instrument in your retirement to keep the grey cells going.
Dave’s been great. I send him over a file as far as I have progressed and he can tell me if it will work for him or not, and I’m getting there.
I have hand drawn/traced over the scan using primarily the bezier tool.
But, back to the square thing and how to register dimensions etc on something that just isn’t square.
So, the starting point is the centre line, because many instruments looked at from the front, are symmetrical. But that’s only one axis of registration. The second axis is through the centre of the sound hole, perpendicular to the longitudinal centre line. So far so good. But that means that any templates have to be transparent and have those lines etched on them and the workpieces and the jigs need these lines on them too, and I, the amateur luthier has to line them all up.
The research showed up that if the templates, the soundboard (top), back, work board, and moulds all had coaxial holes either side of the body on the second axis line, then with a rod in each hole, everything will line up! Bingo! I got that one one from a luthier that handbuilds (so far as one can call them handbuilt these days with CNC machines, but that’s a whole other thread) his instruments and his base price starts at $15,000 for an acoustic!!! So if it’s good enough for him, who am I to argue. I’ve just got to draw all the templates so they can be laser cut, and that’s where I am now. In the middle of drawing them.
You can see the little wings with all the coaxial holes in this drawing which is in fact three different drawings on separate layers on this file; one the outline of the guitar, the next the oversize outline of the template for the back strip, and the last the oversize template for the back braces. Dave instructs me, blue lines for cutting, red lines for etching.
I then build up the next template one another layer. There a couple more to go.
Admin, I don't know what's going on, but on my Mac that background is white!
This WIP is just for making the templates and moulds. I’ll do a separate WIP for the instrument build.
Oh, and did I say that I maybe even trying to invest in a CNC machine next year, so I may be calling on some of your experience and expertise.
I hope you could make sense of all that. I find articulating it here helps me make more sense of it.