rwillett

Someone asked me about support and infill, so I thought I'd explain it a little better. This is the neck module. It will hold a small adapter that allows different bridges to be used. The adapter will fit to the bridge using the number of M3 holes in tourquoise on each side of the module. You can see one side below. The red screw holes are for the pickguard. The three large holes in yellow in the middle horizontal section are for Telecaster bridges which appear to have long screws in to hold the pickup adjustment, longer than 19mm anyway. For the purpose of this we can ignore the holes. The blue horizontal section, the middle of the 'H' shape fits between the 15mm plywood backbone and the bridge adapter. If we print the module horizontally, this section is unsupported. We can get away with unsupported sections around 4-6mm, not 100mm. Not going to work. One option might be to change the printing orientation of the bridge module, print it on the end so that it's vertical like so There are three issues with doing this. 1. Any holes will come out as ellipses as gravity takes its toll. So the large three holes in the middle would need to be designed as ellipses in the vertical axis so they sagged down to a circle. Doable but a pain. 2. Any face that is printed on the print bed, comes out very smooth and very nice. The back of this module is hidden and so this nice smooth surface is wasted. 3. The strength of the module is compromised as the longest filament length is either across the back or from the sides. We want the filaments running long to provide the strength. Sp to get around the problem, we design it how we want it to work, and in the slicer program, PrusaSlicer but Cura works the same, we add in a support enforcer. This manually forces the slicing program to automatically generate support wherever the support enforcer touches the main module. Thats the blue box below. Manually forcing something automatically sounds odd, it means that I tell the slicer program where to do support and it automatically generates the support just for that area. I don't want it to auto-generate support everywhere as it then does odd things in the other holes. I have turned the bridge module upside down so that the top gets the nice smooth surface from the steel plate. If I slice it now, I get The green is the automatically generated support. I have set it to be as simple and wide a support as I can. This is the honeycomb support that I will cut away and discard. All it does is hold the middle section up. We can see in the picture above the dark red which is the infill at 20%. I have set PrusaSlicer to generate an infill at 60% for the middle section (from 15mm from the base plate to 25mm) to provide more strength This is the same model, literally 0.3mm higher. You can see the infill is far more tightly packed. I could go even higher, but 60% is fine. The more infill the slower the print On the whole we try not to do too much support as its an effort to remove and to clean. We also want the lowest percentage of infill appropriate for the job. 10% is fine for a lot of things but a guitar has stresses on it, so this is how we handle it. Hope this explains things. Rob

I'll have a look at it and make a call whether to or not. I've had to use the neck off the first version so that's surplus to requirements. Wpuld test there anyway before I touched V2

And this is what happens 10.5 hours into an 11 hour print when the print head nudges a nut and crashes the print... Oh what joy... Got up at 05:00 to start the print again <sigh> This is what the inside of a large print looks like at 20% infill. That's the cross section in the middle of everything. As you increase the infill, the cross section gets denser and denser. 20% infill is 80% air which sounds quite fragile, but a 20% infill print is quite strong. I wouldn't want to make a step ladder out of it, but for most usages where there is no real stress on an item this is fine. For more stressed parts of the guitar, such as the neck module which holds the neck on through screws, I print at 60% infill. This is very strong and hold compression quite well. All the parts of my CNC machine I made that hold the router are printed at 60%, the router pushs a router bit at circa 30K RPM through metal and wood. 60% printing was easily rigid enough for soft metals, CNCing stainless steel is a different question all together and that needs all metal structures or you take off 0.001mm a time and it takes three months to cut anything out. Rob

The bass guitar will be after the new year. Still need to finish this one off. Had a chat with James from Home of Tone yesterday about the wiring loom and that looks fine. The wiring needs to be custom made with quick release connectors. No idea what it's going to sound like, that's part of the fun to be honest. James is very helpful. I'm looking for a bass neck with tuners. Was hoping for a medium scale as I think neck dive will be an issue. I'll look over the weekend for any maths around centre of gravity and levers. If anybody has a bass neck they want to get rid of, let me know.

This is pretty much the finished article apart from any bug fixes. It has a three section pickguard, but this will be replaced by a custom made one once I know it all fits. The pickups are accurate for the Tesla pickups and sit on a cusom made bed that moves along the axis of the neck, so I can move them closer to the bridge or neck or whatever. Its easy to design pickups that fit to the pickguard or fit to the body now. You can see the mounting holes in the middle below. The neck module has been made and checked that it actually does fit the Yamaha neck. I cannot find a decent neck on eBay so have to use the same one as before. The neck module will fit to the plywood baseplate AND will connect the top and bottom of the guitar through four holes on each side of the neck module. This does allow me to change the neck over at some time, just in case a nice thing 58 Telecaster (or Stratocaster) neck falls into my lap. It'd probably take an hour to change the neck and restring it. If the neck module needs reprinting, thats a lot longer. I did this at 0.2mm and 60% infill, and it took 14 hours just for the neck module. But its very strong now. Cable routing is fairly easy, there are multiple paths to the control area lower left. There are six screws for the lower pickguard to hide it and there is a recess at the bottom for a plate to cover and protect it all. The bridge module allows different bridges to be used. I've put three large holes as the mounting screws for a Telecaster type bridge are more than 19mm long. The two rows of screws allow the bidge adapter to screw in. like so. This has the screw pattern for a cheap £5 ebay hardtail. Here's the above picture in cross section These are the five embedded nut slots in the orange section. If I print this at 60% infill it's pretty strong. I'm currently printing out the bottom left and bottom right parts of the frame. They'll be finished around 21:00. Tomorrow will be a quick dry assembly to check dimensions before I print the final versions of the bridge module and neck pickup module. I may adjust by 0.2mm here or there. I can also use the opportunity to check the cable run lengths for Home of Tone's loom. Over the weekend I'll then print the bridge adapter and the pickguards. I'll do the pickguards in white for the moment as black and red doesn't look that good. My intention now is to use plastic filler on all the seam lines, sand it down using a filler/primer. Get it as smooth as possible, spray with a matt black acrylic and then use an epoxy resin as the final hard coat. I will test this on my old version first. Thanks Rob

Damm, that was the problem, I should have come to you as a sommalier Rob

I have never smoked so that might help. Plenty of other vices, but not smoking....

<cough>I'm absolutely fine<cough><cough>A little bit of late onset asthma and that's it. Most be the pure lifestyle I lead...

Many years ago, I loved making Airfix models, 1/72 of airplanes and stuff. Typical boys stuff, and then would paint them up using Humbrol enamels. I suspect many people here did much the same. I woke up one Sunday morning in my bedroom and all I could smell was White Spirit. I looked on the floor and could see a bottle of White Spirit on it's side, the top off and it mostly empty. I smelt the carpet and thought "Bloody hell, knocked it over in the night and it's all spilt on the floor and soaked into the carpet. My mum is going to kill to me". I went out to the bathroom and could still smell the white spirit, "Oh no, its gone everywhere in the house, my mum and dad are going to kill me". I went downstairs and thought it was downstairs as well, I then starting thinking, so I went outside and could still smell it. The penny dropped, I hadn't spilt the white spirit, I'd drunk the whole bottle in the night whilst asleep. There was none on the carpet, but there was an awful lot in my stomach. I wasn't ill, didn't feel that bad, but my breath was awful and took a day or two to get back to normal. Ever since then, I keep stuff like that locked up in a garage and not in the house. I have never touched white spirts since, I moved to meths instead for a classier drink Rob

Sold two Echo Shows to Tom. Lovely guy to work with. Immediate payment. 100% sensible and great comms. No issues whatsoever. Why aren't more people like Tom? Thanks Rob

I shall say no more....

I've stopped using the brown stuff as its a nighmare. I used to use it to hold screws in thumb screws for my astrophotography business but have moved to a gel super glue instead. I don;t worry about expansion any more but I do glue myself regularly to the office desk instead. I shouldn't be allowed anywhere near anything like adhesives, power tools, solvents, chemicals, glass, flammable objects, gas, petrol, alcohol or guitars. I'll either spill it, break it, inhale it (accidently), adhere myself, drink it, set fire to it or try to play it badly. One day I'll tell you why I'm not allowed near white spirit...

A quick update is that there is no real update I've printed off two pieces of the updated V2 of the guitar and two more test pieces are being done as I speak Hopefully by tomorrow morning I'll have this lot printed, though the neck module and bridge module are test pieces to check the support needed. This is an area of compromise, I want the top of the neck & bridge modules to be printed face down as that gives a nicer finish, but that means that the horizonal sections in the middle need supports. Support provides support for overhangs as the printed material won't just stay up. The green below is a honeycomb structure that supports the middle of the bridge, neck pickup and neck modules. I'll cut out the green and discard it once printed. This is a far chunk of printing though. Out of seven hours, the support printing is 1hr 55min. Still got this to print The astute will notice that there are no mounting holes in the neck module. That's because something went wrong in the design and I have no idea what Also need to put pickguard screws in. I have been testing Flopast (https://www.floplast.co.uk/product/solvent-cement) and it's great stuff. I cannot separate the parts once glued. I'm going to try and find out what the strength of the bond is. I suspect the bond is stronger than the 3d printed material itself. £9 a bottle, doesn't seem to have a bad smell, though as I have no sense of smell due to something happening 10 years ago (no idea what), thats probably not a good recommendation. Easy to apply, doesn't expand (I'm looking at you Gorilla Glue), doesn't dry immediately. Whats not to like? Once this is done, I'll dry assemble and check fit. Things might be out by 0.5mm or more or less or not at all. Printing can vary depending on time, temperature, filament, sheer bloodymindness of something or the other. The glue is kept well away, but at this point I can measure things for the wiring harness. House of Tone are just waiting for me to finalise things so they can get it built. I did look at the finish and I'm tempted to look at coating this in an epoxy resin finish. https://www.matterhackers.com/store/l/xtc-3d-high-performance-3d-print-coating-24-oz/sk/M3KW1WX0 However thats for another year. Rob

They look good, though I had some hand clamps already. Thanks

Oh no! Must not even look at this, too late, and there's loads of other guitars as well. Damm, another morning of work lost wondering if I can justify an vintage Fender. I do like the look of the 57 Strat, but I know nothing about these things. Rob

Mine are Irwin hand clamps. They need to fit inside the honycomb so these are ideal. The G clamps in Thingiverse aren't that strong and aren't suitable for clamping honeycomb structures as they need to be long nosed. I did try some years ago when I built a CNC for myself but they weren't a great success. I will also use long wood clamps for clamping across the whole guitar body at the end.

This weekend I experimented with glue. I don't believe I have ever written that phrase in my life before I'm trying to simplify the construction but keep the rigidity in the frame. Floplast looks the business, easy to apply, doesn't immediately go off like superglue and is a solvent adhesive. To avoid using screws and embedded nuts, I designed a simple dowel and hole system I can print. With wood, this is relatively easy, with 3d printing, there are limitations. If you print a hole that is vertical, it is likely that the hole will become ellipitical as gravity comes into effect. If you print thinner layers, then the ellipse is less but is still there AND it takes a hell of a lot longer to print. If I don't print this axis vertical, then something else is compromised. In my case, I want the front of the guitar to be printed on the steel bed as that gives the best finish. Ironing looks rubbish in my opiion. YMMV So I design an ellipse that prints a 3mm round hole when printed vertically. In Fusion 360 this is a 3.4mm on the major axis and 3mm on the minor axis. I also print 8mm long M3 dowels which take 4 min to do each. This means that the components should align pretty closely when clamped together with glue. I have a load of decent hand clamps just itching to be used. I've now completed the top of the design. Got space for a three way switch at the top right, changing that from a 30mm hole to a 40mm hole took a load of work with cable routing. Small changes can mean a lot of unpicking in Fusion 360. Sometimes large changes are dead easy. The face closest to you has six holes, two are for dowel alignments, the other four are for the neck module. The neck module is designed to come out and is not glued in. This allows me to change the neck over. The four holes are for four embedded M3 square nuts. These nuts are square and not hexagons as they go in vertically and if they were hexagons, you couldn't get the shape filled in through 3d printing. You can also see the 40mm hole for the three way switch, a hole for the strap button and five M2.5 holes for the pickguard. The back has a cover plate recess. Again three M2.5 holes with embedded nuts. As these are laid horizontally, I can use cheap hexagon ones as M2.5 square nuts seem to be rare. The 5mm chamfer on the edges is printed at 0.15mm using variable layers in PrusaSlicer. This is the top left of the guitar in PrusaSlicer Just under 13 hours of printing with a pause six hours in to put one M3 nut for the strap button. Both these jobs will get started tomorrow as they do require me to intervene and put nuts into certain places. Rob

I wouldn’t say design process as such , more the fumbling of a blind man with his eyes closed in a dark room searching for a black cat who may or may not be in the room

It's a good idea usind aluminium extrusion. Didn't think about that. I'd be a little cautious of 2020 as it does bend, however there may be different grades in use that are better than others. The nice thing here is that you can attach an awful lot of stuff with t-nuts which are cheap as chips. Can't work out how he's done the neck. Is it printed? I'm out and on my phone so can't quite see.

That could be a mistake stating that...

That's an interesting question, so far for my six strings, not an issue. However it could be, given the size and weight of a bass neck. I did think that this would be a problem for a bass. One option might be to make the end of the body hollow to pack weights in, enough to balance it out OR use one of the anti-dive straps. I do know that my V1 is quite light, certainly lighter than my 89 Telecaster. I can't see the advantage for me to build a neck. I don't have the skills and I couldn't do a better/cheaper job than buying a decent neck. Thats a bridge too far for me <no pun intended> The design workflow is important as you are basically programming the model from step 1 onwards, you are applying instructions to sketches, extrude this, split this. Then apply a sketch to that part of the model and do more instructions. The way you plan this is important as the order is critical. Miss a bit out and it doesn't work. Bascially a short scale SG? Rob

Happy for you to steal what you like. The key thing with this version is that it's easier and simpler to make. The next version will be a bass, probably not a five string short scale headless, but I want to check some stuff out with V2. The design workflow is important. The order you do things is really important and I did it the wrong way for V1, but I might have done it the right way for V2. Basically get the 'master' dimensions roughed out, width and position of bridge, where does the neck go, how high is it? Position of pickups is pretty unimportant from a design point of view. Once you have that, then do the honeycomb, but do it as a repeating pattern, and make each side big enough to handle a clamp end so you clamp to glue. The repeating pattern requires maths but it's not difficult, simple trigonometry. Overlay the printing size of your prusa and then start looking at outlines to fit. Its a bit like object oriented programming to be honest Rob

I have now almost completed the design for the next version. I don't think a single component has been carried over from V1. Some of the neck measurements and the plywood backbone have remained but every other element has been redesigned based on what was learnt from V1. It looks similar but thats about it. The original ideas for the first version were: 1. All my own design so nobody can claim I'm stealing their design. - That still stands 2. No glue. I hate glue, it gets everywhere - I am now experimenting with glue. I have a number of different types of glues from various superglues, Bostick Hard plastic Glue, and the current favourite FloPlast, a solvent cement from my local builders. 3. As there is no glue, all fittings most be as hidden as possible. - This still stands but I have significantly modified the structure to make it easier to print. I have removed most of the bolts and screws from the outside structures and am assuming glue will hold them together. Certainly Bostick Hard Plastics glue and FloPlast are very strong. 4. Must be modular. I don't know which bridge to use yet, I don't know which pickups I want and, importantly, I might want to change them or add three pickups without having to print everything again. Completely rethought how this works. Before, I would have to unscrew the whole guitar to change the bridge or pickups. Not any more, I've thought about this and now have a simple set of adaptors. 5. Must be able to take different necks. I don't have a neck I can use yet, so not sure what I'm going to get. I'm looking for a thin telecaster neck but not found one on eBay I trust to buy yet. Struggling to find one at the price so the Yamaha one off the proof of concept is going to be used. 6. Must be playable. The last guitar was light and easy to play. 7. Must be easy to print and fit on a 220mm x 220mm print bed. The Prusacaster one takes four days to print one part. No doing that This is still applicable. I have changed the design to make it printable without a lot of interventions from myself. I'm now down to four big pieces rather than five. 8. Must be able to use different controls as I have no idea what I'm buying, Telecaset and Stratocaster wiring is easily available second hand on eBay so thats a good start. This version is going to be based around a Telecaster Deluxe. I also think that a lot of the control sets on eBay are junk so am working with House of Tone to get a better set of pots and controls. 9. As few as possible supports for 3d printing. This has zero supports needed at the moment. I'm delighted with that Lesson learnt from the previous guitar is that I need to print the top of the guitar facing down to get the nice smooth finish that the Prusa satin plate provides. This means supports for the three modules in the middle. However as these are hidden from view, no so concerned. So I've picked up a pair of Tesla pickups, thought a lot more carefully about the design and parameterised just about every dimension so I can adapt as needed. The Tesla pickups are bottom mounted so are designed to fit to the guitar and not to the pickguard. That has spurred me to make the pickuops more modular. The same with the bridge, I've gone for a cheap and cheerful hardtail off eBay. Its not quite finished yet, but the second iteration design was a lot easier as I had learnt from the first one. If I take the pickguard off You can see a row of mounting points. The bridge uses these mounting points, in this case the tesla pickups do. They can be moved back and forward to change the tone. I could even get a third pickup in. There's a tiny mounting plate to make the Tesla pickup work. There's now a cable channel to the three way switch on the top. More routing ports to the four pots at the bottom. Learnt my lesson and provide a lot bigger space for controls. The back will have a simple plate that fits across it to hide the void. The strap button mount points are in. Things to do are: 1. The output socket channel. 2. Put the screw holes in for the pickguard. The pickguard will have to be printed in sections as it's too big for my printer. If it works, I'll get one made to measure. 3. When the bridge arrives, make the mounting points on the bridge. 4. Finish the neck mounting section. 5. Keep experimenting with glues just to check stuff like shear strength. Some of the glues are very strong, but how about if I knock it sideways or heat it up? 6. Hope and pray that the Tesla pickups aren't too high. I'm working in mm here and I reckon I have around 2mm spare. I do have a solution to lower the pickup by 4mm but it's a hack. Trying to finish this for Xmas, but have done no printing so far. Lots of test prints to check, but nothing real yet. Rob

Oh I do have a basement, its full of a large biomass boiler, hot water tank, pipes and boxes we haven't opened from the last 2-3 hosue moves Rob

@Andyjr1515 Thanks for your really nice comment. Appreciate it. I originally was going to use a Telecaster kit from a supplier to provide the neck, bridge and electrics, but after building it, I found the shape of the neck was too deep and I struggled to play it as my thumb was in agony after a while. Too many rugby injuries have taken their toll on my body. So I built it, enjoyed doing it with my daughter and gave the guitar to the local schools music dept who were very happy to take it off my hands. By this time, I had laid down the foundations of the 3d printed body and had designed the neck module depth (not width) to fit the other guitar neck. I then started looking around for a guitar neck to use instead and found somebody selling the neck I used on eBay. I took a gamble and it's a great neck. I'm 90% certain it came off a guitar similar to this https://www.axebition.com/electric-guitar/yamaha-rgx-121d. It's stamped RG121DM on the end but no date I could see. I'll be honest and say it never ocurred to me to change the neck height in the 3d printed neck module to compensate for the fact that this neck was not the one I planned for. My thinking is that the original neck was thicker than this one and simply putting a 1.6mm shim in brough the neck up to the same spec as before. Of course that could be complete b0ll0cks and it all just worked. I think the more experienced amongst you are ascribing a level of planning, competence and expertise to me that is wholly unwarranted, I think in my case three wrongs made a right. I've never thought about building a guitar before, so I tried to work out what I presumed would be the fundamentals, the length of the neck from the 12th fret to the bridge, the height of the fretboard and the height of the bridge. Everything else was just guesswork and trying to make it fit a shape I recognised and could print. In hindsight I made so many design and printing errors, I am mortified I got so many things wrong. Anyway, I have now: 1. Shimmed the neck up by 1.6mm 2. Lowered the nut by 0.5mm, glued it on using wood glue. 3. Raised the saddles so there is more adjustment. 4. Drilled a hole in the bridge module so I can run an earthing cable. As this is a 3d print, drilling is normally a big no-no, but as this is a proof of concept, I wasn't going to print another module, this time with a hole, and spend 10 hours waiting for it. 5. Put an earthing cable from the bridge to the ground on the control panel through the newly drilled hole. 6. Swapped the wiring around so that the switch works the right way. 7. Repaired the output socket. 8. Fixed the loose knob 9. Set the string height so its the same as my MIK Telecaster. 10. Tuned it up. 11. Plugged a NUX Mighty Plug Pro, attached headphones and strummed a barre G. Well knock me down with a feather. The damm thing worked, hum was almost all gone, tiny bit in the background but I've heard worse, it sounds great. The neck pickup sounds better than the one on my genuine Telecaster, the bridge pickup, not so good. The tone controls work. No neck buzz, no idea why, luck I guess, the 3d printed nut is fine, no idea how long it will last but it's 24 mins to print a new one. I'm going to leave it overnight and see if the strings go out of tune, but I'm quite pleased with how its turned out. I can still see every mistake I made (and there are lots) but not too shabby for a first effort. Now for V2 Rob