A 3d Printing Journey

Discussion in 'Luthier's Corner' started by AbnormalForms, Oct 4, 2022.

  1. AbnormalForms


    Sep 22, 2022
    Got into 3d printing a few years ago and while scrolling the internet for ideas on what to print, I stumbled upon some really cool 3d printed guitars/basses and thought it'd be a cool project to do. But of course, as I had to stroke my hubris to go against the grain and do something different, I noticed that a vast majority of the small niche of 3d printed guitars were only the body. They still had wooden necks. And so I thought, well, how difficult would a nearly 100% 3d printed neck-through bass be? And so I set out to find out exactly that.

    After reading several threads and digging around, I found that a good practice for 3d printed instruments was to have some sort of back-bone or stiff rod running through the body to support the tension of the strings. My first design implemented 2 steel 1/4th inch round rods running parallel down the neck that was printed in slices and stacked together. There was no truss rod, as I didn't want to be out of my only spare in case it didn't work out. It was a headless with the tuners built into the body to releave stress on the plastic neck and I threw in a gimmick of being able to remove the top of the central cavity to test out different pickup types.
    Needless to say, this one flopped due to several oversights on my part. In the 3d printing world, there are 2 kinds of popular plastics, PLA and PETG. PLA is stiff, brittle, and tends to warp at relatively low temperatures (it bows even in a hot car in the summer). PETG on the other hand is mildly flexible and much more heat resistant, which is why I chose it to test this neck through with. However, it was much too flexible, and after only putting on 1 string, you could land a plane under it. Without a truss rod, there was nothing I really could do with this guy to alleviate such a problem, and so I moved onto the next.

    Taking all that I had learned from the first, I decided to go with a single cut design on the second. This time around, I made sure that the neck was going absolutely nowhere by fitting a 3/4 inch square steel tube down the length of the neck, taking the Wishbass approach of sacrificing a truss rod for a fairly thick neck. I once again played up my hubris and designed this one with the gimmick of installing a MIDI keyboard and a synthesizer on the bass side of the neck, which, while still a fun fantacy of mine, didn't come to fruition here...
    This time, indeed, the neck stayed completely straight. However, I wanted to protect the fun pattern on the fingerboard that I painted on and decided clear 2 part epoxy would be the best approach. I set up guards around the fingerboard, but it clumped up along the sides and required a lot of sanding to get flat, so much so that I started cutting into the plastic underneath toward the bottom. Whoops. But the worst was yet to come. One night, I had taken it to practice to show off, and low and behold, when I took it out of the bag, the head had sheared off in probably one of the worst ways possible.
    Some more 3d printing shenanigans. How the process works is the machine lays down a thin line of plastic, going back and forth until it fills up a layer and then starts adding another on top of it. This shear was on one of those layer lines. Yes, I could glue it back on, but there's nothing stopping it from shearing off at a layer line above it again unfortunately. I switched over to PLA for this neck and the brittleness definitely kicked in. Also, as you can see slightly from the picture, 3d printing kinda cheats as it's not completely one solid chunk of plastic. It has what's called infill that supports the ceiling of the print once it gets there, meaning most 3d printed guitars are naturally "chambered" by design. I opt to use thicker walls to support the tension of the strings with less infill to offset the added weight. Hollow body infill is also the reason you can't just route a new pocket for say, a new pickup, into a 3d printed body, making it somewhat of a customizable downside of this practice.

    So that leads me to yet again another design. This time, I wanted to throw the gimmick into the overall theme of the bass and settled as steampunk as a cool aesthetic to go off of. Naturally then, the design of this one took much longer than the other two, but covid gave plenty of time to do so. I also had one big advantage this time around over the previous attempts: a treadmill printer. Normally, 3d printers are confined to an average of 1 foot cubed, however, a treadmill printer uses, well, a treadmill as it's build platform, meaning you can print things infinitely long in one direction, making the whole neck-through platform one continuous piece rather than several glued together, proving quite invaluable to the success of this third design.
    I once again went with a thick neck and 3/4 inch square rod. In theme of the gimmick, I used some hook screws with thread joiners cut in half and welded together as tuners and a plate of brass to stop the screws from digging into the plastic body. The fingerboard was actually a cut piece of clear acrylic this time around to show off the thick steel beam going down the neck, which proved much easier to work with over the resin. I also attached a reinforcing jacket around the back of the head to prevent another shear. All of this culminating (finally) into a successful fully 3d printed neck through bass.
    IMG_20211101_014442590.jpg IMG_20211101_014149649.jpg
    While definitely not the most comfortable to play on your knee, it's more of a looker than a recreational practice bass, but man am I proud of how much of a looker it is. Unfortunately, the LED wire I strung through it interferes with the electronics to much to have it on while playing (guess I should've seen that one coming). I haven't tuned it to standard yet, still too worried from the other bass's head snapping off. It's been around for about a year now and there's no sign of it warping or giving under the tension of the strings, although the action is a bit high with the saddles bottomed out, but that may just be an oversight in my designs. A non-3d printed bridge would probably help remedy this, but I'm not too worried about it.

    Here's a video for those curious how it sounds. It's straight in, no preamp.

    Anyways, this is by no means the end of this 3d printing journey. Got a couple more builds that were body only prints that I have more in-progress pics of that I'm planning on posting here *soonish*, probably in the Luthier's Corner where it belongs (even though I have no clue how to do any form of woodworking outside of drilling holes in necks). Appreciate you getting through the wall of text, and heck, even if you didn't, hope you enjoyed the pics/my mediocre playing video. Got a small preview for what I got cooking currently for ya.
  2. MovinTarget

    MovinTarget Supporting Member

    Jan 30, 2018
    Maryland, USA
    Very cool!

    I had pondered doing bridge tuners similarly as you get so much more distance the ball end can travel which is nice if you are dealing with a short scale and can't get perfectly length'd strings... I don't have the welding skills for it though...
    AbnormalForms likes this.
  3. Right on man thats really cool...
    My son is going to get himself a 3D printer so i showed him your bass,,he says super cool as well....Cheers!
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  4. AbnormalForms


    Sep 22, 2022
    It worked out pretty well here, but I'm not sure I could recommend the way I did it here. I tried something similar to this on another bass, but with grubscrew ends like you would find on a regular headless bridge, but the tension became too much to the point where it wouldn't turn anymore. But if you do try one like this, I had another set of these string holders that I glued together with loctite 2 part steel epoxy that worked perfectly.
    MovinTarget likes this.
  5. Sub41


    Jul 13, 2006
    North FL
    Thanks for the detailed post. I saw that in your avatar and wondered what it was all about. Very wild.
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  6. Killing Floor

    Killing Floor Supporting Member

    Feb 7, 2020
    Austin, TX
    That’s really cool. Fun project.
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  7. MovinTarget

    MovinTarget Supporting Member

    Jan 30, 2018
    Maryland, USA
    well, epoxy... *now* yer speaking my language :)

    Though I'd have to look into steel epoxy, haven't used that before.

    I suppose some thrust bearings would help with the tension...
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  8. AbnormalForms


    Sep 22, 2022
    I used it to glue together all of these basses, it's great stuff. You can actually see it in one of the pics I have up there. I guess I was wrong on the loctite part, it's actually J-B weld. It held the bottom part of the one that had the head shear off while it split at the layer line, strong stuff.

    Your bearing idea is a great idea, might have to go back to the drawing board and finish that one up then...
    MovinTarget likes this.
  9. AbnormalForms


    Sep 22, 2022
    Thanks! 3d printings a great hobby to add some nice looking things to your shelf. Some advice I'd give to people starting out is that the printing is only half the hobby. There is a hidden second half in post processing. Even if you don't sand the print, there's always something to glue together/remove excess plastic/calibrating the printer. Patience is absolutely a must for great prints. Hope he enjoys it!
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  10. Outbush


    Nov 6, 2016
    Pearler- congrats!
    AbnormalForms likes this.
  11. I like this idea very much, but the lo-fi tuners are the best bass detail I've seen in years! And the sound is pretty cool!
    AbnormalForms likes this.
  12. MovinTarget

    MovinTarget Supporting Member

    Jan 30, 2018
    Maryland, USA
    Thrust bears are big in the headless bass club. I've only ever used one system that has the; Nova Headless, but they smooth and help alleviate the tension...

    Comments are sprinkled all over recent pages but here are some money shots:
    Headless Club???
    AbnormalForms likes this.
  13. J Posega

    J Posega Cat Dad and Dingwall Enthusiast Supporting Member

    Jul 16, 2005
    Portland, OR
    That's really awesome. Do you have any experience with other filaments? I know there are some impregnated with carbon fiber, some with wood fiber, and I guess even metal 3D printing is a thing now.

    I'd like to get into 3D printing. I'm not a design or computer programming kind of guy, but a 3D printer is the closest thing we have to Star Trek's replicators.
  14. JRA

    JRA my words = opinion Gold Supporting Member

    very cool --- and a fretless to boot! :thumbsup:

    great pics/narrative of the process, congrats! :thumbsup:
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  15. mikewalker

    mikewalker Supporting Member

    Jul 30, 2017
    Canada, Eh!
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  16. AbnormalForms


    Sep 22, 2022
    I actually recently tried making a bass body out of carbon fiber infused nylon, "plastic aluminum" as some had called it while I was looking around studying, some of the toughest "normie" commercial plastic you can print with that won't cost you selling your car for it but still relatively expensive in the 3d printing world. Took a lot of special add-ons to the printer to get it to print well: a full heated enclosure to keep the filament dry, vacuum sealed bags to store it in, a full metal hot-end with a steel nozzle (they're normally brass), and a special kind of build plate to top it all off. Once all set up though, it printed great! Had a little bit of warping due to me not fastening the bed down well enough, but it was manageable to put it all together. I screwed up big time when the steel rod I would've used to reinforce it didn't fit in the slot and just decided to glue the pieces together without it, although in the end, I'm not sure how much of a difference it would've made on that particular print. I had a wooden neck for this one, but just like the first bass I made above, after stringing up just 1 string, the action was already abysmal. Looking closer at it revealed that it was bending at the neck pocket itself, meaning slapping a log piece of steel down the back to reinforce it wouldn't fix this. I may come back to this some day by drilling a hole into the sealed shaft and filling the slot with a thinner rod and epoxy, but carbon fiber dust is no joke and might just take more effort than it's worth, as the shell of the print was the part flexing and the infill probably isn't thick enough to support the flex. While it was a somewhat costly endeavor (it used nearly $100 of material, not including all of the printer upgrades), I'm still glad I experimented with it and may come back to it some day with some thicker infill and proper stiffening support. While it is rather flexible material, it's pretty dang tough and really doesn't care about the heat at all, making it an excellent choice for the rough and tumbles of touring (at least I imagine so, I've never done so myself yet).
    As for other plastics infused with CF, I've seen some reviews saying that it makes the plastic more brittle, which may be nice for PETG, as it's heat resistance would be nice with some stiffness (yes I know ABS exists, but that stuff is a pain in the behind to print well), but more brittleness is the LAST thing that PLA needs (see head shearing pic above). Haven't really looked into metal infused plastics yet, a bit out of the budget for now and the single roll of wood filament I have didn't really seem to affect the characteristics of the plastic, but it did make it look very nice when stained. Anyways, have a couple of pics of the CF body for getting through my wall of text, it prints with a very cool matte black:
  17. AbnormalForms


    Sep 22, 2022
    I, uh, *may* not have the tools to properly install frets yet... hehe

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  18. T_Bone_TL


    Jan 10, 2013
    SW VT
    On the head snapping off front, extend your neck reenforcement all the way into the head area, don't stop it at the end of the neck.

    On the reenforcing front, you could print channels to place carbon fiber tow epoxied into place, rather than a big ol' hunk a' steel.
  19. AbnormalForms


    Sep 22, 2022
    Definitely learned that lesson here the hard way. The reason it wasn't all the way on this particular model is because it would have started poking through the channels I cut for the strings to go down. Needless to say, making sure on the next one that the reinforcement bar goes all the way to the string holes.

    I messed around with channels for a couple of 6mm CF square rods I got off of amazon, 2 down the sides of a channel for a truss rod, but trying to print it was a headache. The walls between the channels were thin and popped off of the build plate before it sewed them all together. Cutting CF rods is also messy business, but that's probably because I use a diamond cutoff tool on a dremel which gets it everywhere. Granted, this was before I had the treadmill printer, which may fair better with the channels due to the way it prints. This has made it's way up the testing charts along with a working truss rod. Appreciate the advice!
    Last edited: Oct 6, 2022
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  20. Reedt2000

    Reedt2000 Supporting Member

    Apr 26, 2017
    Central New Jersey
    I know nothing about this, but it looks really cool and I'm in for seeing what else you do with it!
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