This one’s been a bit of a saga – laser-cutting fret-slots, laser-etching fret-marker holes, laser-etching nut slots.
The main reason it’s been a saga is that the guitar is too tall to fit under the laser-cutter beam-guide. The next laser-cutter I get, I’m going to build myself. The way the Chinese ones come in a giant metal-box is a bit of a pain, looks kindof crap, is non-modular, and takes up a fuck of a lot of space. Basically means you need a room just for the laser-cutter.
Anyway, it turns out that if I take the floor out of the laser cutter, I can attach a couple of DIY clamps to the edge – which allow me to raise and lower the guitar neck.
Lowering the floor like this means I needed to extend the lens-focusing tube – which took 3 goes
So… massive learning curve, probably ought to write down what I’ve learned (now that I’ve done 2 necks using this method)
1) The DIY clamps are still too wobbly – use real clamps. Not pegs, not tape, not rubber bands… real clamps, because if you accidentally knock it, you’re going to spend hours trying to get things to line again. Tie the neck down. It has to be rock solid.
2) don’t bother with making a template – eyeball it.
3) if you’re using pre-made fret markers, test your etch on a bit of scrap wood first. If you make the holes too big you’ll need new fret-markers, if you make them too small, each one is going to take about 1/2 an hour to fix.
4) so get it all done in one shot.
5) this means getting the laser clean, focused, and operating at full-power, with the nozzle-extender. The nozzle-extender makes this a LOT harder to do. It’d be good not to have to do this actually. Pain in the arse.
6) it’s a lot easer to fix a randomly placed dot-pattern than a uniformly spaced one.
7) it’s a LOT easier to make your own fret-markers with laser-cuttable material. The pattern you use to etch the hole is the same pattern you use to cut the inlay material. Sometimes you have to bodge for kerf etc, but not usually.
8) you can’t cut bone with a laser-cutter.
9) do all this stuff before you shape the neck
10) making a separate fret-board will save doing all the table-lowering stuff. So make separate fretboards from now on.
Anyhoo… pre-sanding, fretting etc.
A lot rougher than I’d like… but I might be able to fill some cracks with epoxy after I’ve calmed down a bit, and everything in the whole world is a bit less annoying. Oh yea, and the frets are upside down. Mind you, so are the pegs. It’s got that whole Hendrix thing going on. It’s from Down Under. What do you expect?
Okay, so I finally got it together to make the headstock on the main guitar…
… and I like the headstock on the Pixie-Stick (the mini guitar I’m making out of offcuts) more. I like the pegs more, and I prefer the vaguely Katana-like (with holes) shape.
Arse. That’s an issue, because the Pixie-Stick uses violin tuning pegs… which are basically just bits of wood jammed into holes, and which are a bit of a bastard to tune with.
So I did a whole load of searching, and found these:
Planetary gear tuners
Which are made by Perfection Planetary Pegs, Wittner, and Pegheds.net. These won’t actually add anything to the price of the ingredients… unless you’re buying the cheapest tuners you can find off ebay, rather than proper grown-up ones off Stewmac. Right now I’m in experimental mode, so everything is cheap.
You can also get midgital ones for banjos etc, but I’m looking for more of a violin look… so longer ones it is.
Also worthy of a mention are Steinberger Gearless Tuners…
… but apparently they can’t handle multiple tunings… and guitars I play are all about multiple tunings… so I guess I’ll be trying planetary geared violin tuners.
So I guess I’m now working on Guitar #3
As far as I can gather, normal guitars don’t use expoxy to seal the fret-markers… they just use fret markers about 3mm thick, then sand them down.
I’m attempting to use materials that can be laser-cut though – and that means thinner paua/abalone in laser-etched holes, which means I need to make a dome of epoxy over each one, then scrape/sand them down until they’re the same height as the fretboard. This has taken a fair bit of trialing and erroring (mainly erroring) so I thought I’d best write down what works
1) epoxy doming resin (in picture)
2) two little plastic shot-glasses. You can get these 50 at at time at “everything for $1 shops”
3) little scales, as used by small time drug-dealers. Also in picture. Get them from your local head-shop.
4) a little plastic stirring rod.
5) a little tray/bowl of boiling water
1) in each of the cups, weigh out exactly a 1:2 ratio of the resin and the catalyst. Get this wrong and it will never dry. It doesn’t take much to fill the fret-marker holes… I go for about 2g – which is way too much, but it makes mixing easier.
2) put each in the little cups into the hot water. Hold them under for 1 minute. This makes the liquids easier to pour
3) pour one into the other… and stir slowly for 30 seconds, keeping it in the hot water. The hot water makes mixing easier, and gets rid of bubbles
4) transfer the whole lot to the other cup. This makes the ratios more accurate, and leaves you with two cups you can use again. If you don’t do this one cup will stay sticky forever. Stir for another 30 seconds, keeping it in the hot water.
5) using the stirring rod (or a matchstick etc), drip blobs of epoxy onto the fret markers… push the epoxy right to the edges of the holes, keep dripping until the expoxy meniscus is above the wood. It’s useful to have a bright light / window behind the fretboard) as in photo – makes it easier to see what you’re doing.
6) leave for 3 days. Keep the stirring stick somewhere handy… you can test the dryness by touching the stick rather than your markers. If there are bubbles, you can get rid of them (5 mins after the epoxy is poured) by using one of those little pen-sized blow torches… lightly brushing the epoxy with the flame. If there’s likely to be dust, make a cover to put over it. A long bit of cardboard will do.
After 3 days it’ll be cured. Hotter climates mean faster curing time… but it’s winter here right now, so 3 days it is. I scrape the surface using a razor… as shown here, then use fine sandpaper, then a dremel polishing wheel (very light touches). I’ve found that using a power-sander totally screws up the epoxy. It’s almost like it melts it.
Anyway – there it is.
Pegs installed in the Pixie-Stick
I’m not sure how well ukulele pegs work, but dagnabit, I love the way they look.
The Pixie Stick is a guitar that I’m making out of offcuts… because I’m scared to do anything to the Guitar #1 that I can’t rollback.
The fret slots here are laser-cut… didn’t go quite deep enough, so I made them the right depth (about 2mm) with the DIY fret saw from a couple of days ago.
I can’t install the frets until I finish the fret-markers though… and it’s proving to be quite difficult. It’s currently looking like they need to be sealed with 2-part epoxy. I’ve tried superglue, aryldite epoxy etc etc… people who know say “epoxy doming resin”… like boat-builders use. So that’s what I’ve got, but it takes 3 days to cure. The first attempt didn’t work, so I’ve tried it again… this time measuring the component parts exactly, and heating in boiling water before mixing. This way creates virtually no bubbles… feels better… but I still have to wait 3 days to find out.
For the pixie-guitar, which is largely experimental, I decided to use violin tuning pegs, which is probably ill-advised (in fact I was advised not to by the bloke in the music shop), but if you do what you’re told all the time, it’s not really experimenting. So there it is.
1) Take photos of the headstock
2) Superimpose drawing over it
3) Cut out cardboard templates on laser cutter
4) Tape them to headstock, drill, sand etc
All of which took about about 1/2 an hour or so… although I generally play with designs etc for a couple of days before cutting anything.
What took a whole lot longer, is that the holes are exactly the same size as fingers… and if you stick your fingers into them, you can’t get them out again. So all up, this bit took an hour.
Something that’s becoming abundantly clear with all this, is that it’s a hell of a lot easier to mark hole positions etc etc, using a laser-cutter on the wood first. Trying to get things to line up afterwards is time-consuming and fiddly. It might even be best to drill the holes all the way through with a laser-cutter… even though it basically leaves a charred hole. Holes can be widened… even if they’re just guides.
Yea, yea. Get a CNC mill. Getting harder and harder to avoid. Trouble is, I don’t have anywhere to put it, without doing some <airquotes>Tidying Up </airquotes>.
Even though I’m cutting the fret-slots with a laser-cutter, I’ve found that they sometimes need embiggening, so I needed to get a fret-saw.
I think I might have got really small frets or something… according to the internets, a .58mm saw should have been thin enough… but I got a .5mm one, and it’s way to thick – so I panicked and got a Japanese saw blade off the web… .3mm. That ought to do it.
The whole saw would have cost about $120 – so I just got a blade for $40, and made my own.
Turned out quite well… you can adjust the height of the blade, and retract it completely when it’s not being used.
I think I might make more of them to try to sell on the webs. These haven’t had a proper sanding job done… and are made out of Rimu laminated MDF… it’d be better to make them out of proper hardwood. Not sure if I can laser cut that though. Maybe I should buy a router. You can get them for about $1500 now.
When you have a laser-cutter, everything looks laser-cutterable.
Neck shaper – you fold a bit of sand-paper over it and use it as a shaped sanding-block. It’s basically just this shape
cut out of MDF about 10 times, with bits of dowel keeping everything in line. Works like a dream, and you can make different ones for different necks… if the pieces of wood are different sizes.
I personally think laser-cutters are more useful than 3D printers. Little tools like this take about 10 minutes to make, and are incredibly useful. True it’s not proper 3D – just a shape built up out of layers (mind you, 3D printing is a shape built up out of layers as well)… but it’s really fast, really cheap and you can make big stuff.
Something I hate to say, but have to though… you’ve got to have your own one.
I did a computer science degree back in the days when computers were the size of bulldozers, and each one had a priesthood to offer it the programs written by drones (like us), and who would (several days later) return to us inch-thick piles of printed-out syntax errors. This is how we were taught it would work. Computing time was so valuable, it had to be rationed out, and the act of programming was “measure twice, code once”.
That isn’t the way things turned out.
It is (however) the current state of rapid-fabbing… with online services etc. It’s not the future though… the future is having the machines yourself, which I’ve learned from first-hand experience. If you’re going to be tinkering with rapid-fabbing, you’ll find yourself playing an entirely different game if the trial->error iteration-time is 5 minutes rather than 10 days. You’ve got to have your own machines.
Anyhoo… this is the current state of guitar #1
Okay – bigger hole at the back, held in with black hex bolts, because I like black hex-bolts.
It works pretty well… looks ok, doesn’t rattle.
I’ll use this one for the first guitar… Guitar #1… although I’m actually making 2 at the same time. For the next one though, I’ll try to make something with a completely removable front. Even the larger hole doesn’t provide enough axis, and if you’ve got a completely removable front, you can change fronts.
Welcome to design bungle/iteration number #1
I figured early on that I was going to need to have some way of getting at the electronics once the thing was put together. Normal guitars have removable scratch-plates… normal cigar-box guitars (if they open at all) are openable, on account of being boxes.
But this is not especially normal… here’s my first attempt:
it slides backwards and forwards… and actually looks pretty good I think, except that:
1) it rattles
2) it’s not really big enough for what it’s needed for
3) it takes about 3 layers of wood on the inside… so is kindof bulky.
The pegs/plugs are there just to make it easier to line the various bits of wood up. I quite like them, even though they’re a bit function-over-form. Part of… I dunno… “art” I guess, involves “finding a voice”. Finding something that you do, that makes you unique… and I think a bit of function-over-form might be a cool thing to do. So… lose the sliding door, keep the pegs.
So I figured out how to do kerf-bending on a laser-cutter.
I originally did this to make an enclosure (pictured) for my Raspberry Pi, which I have sitting next to my parent’s TV, so it can get the internet, and the don’t have to watch TV any more, because TV makes you stupid.
Then a bit later I was working on something else – and found myself with some swamp-kauri… which is wood that’s been lying in a swamp for thousands of years… the oldest I’ve seen is 35000… my bits were only 3500, which is about the age of the Biblical Exodus… and the first half of the fairly strange and charismatic 18th Dynasty in Egypt. Tutankhamun, and Akhenaten were of this Dynasty.
It’s beautifiul… you can’t really see it here, but it has this tiger-eye effect that shifts with your perspective – and when you laser-cut it, it smells like sandlewood.
So the two came together at about the same time that I discovered that there’s this whole subculture of people making cigar-box guitars on the internets
And the rest kindof writes itself.
One successful cardboard mockup, about 100 wooden failures.
I’m making the world’s most expensive firewood.
When I was a kid, me and my brother went to the garden centre and got to choose some pot-plants. The rubber-tree in the photo above is my pot plant. It’s grown.
Anway, In the end I gave up trying to wing it design-wise, and wound up writing a program to generate the kerf-cuts.
And then gave up on that, because anything longer than 600mm won’t fit in my laser-cutter… so it needs to be a two-part thing. Predictably enough, the length of the wood that makes up the box is the sum of:
length x 2
width x 2
(corner radius) sqaured x pi
material thickness x 2
Although this seems to be kindof temperamental, so you’re probably better off making a top/bottom to fit the curved part, once you’ve made (and them measured) it, rather than making the top first, then trying to make the kerf-bent bit later.
I started out using double-sided Rimu MDF laminate… which is about 4.5mm thick… wound up using 3mm thick single-sided. The bendability of the thick stuff isn’t that great.
Anyway – eventually got somthing to work.
I’m going to try to make another one tomorrow… I’ll try to get a video together of the entire process.