Creating form factor for own instruments

Sound Design, Tech Development, DIY
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I thought it might be nice to break down the lets make an instrument topic…

so in this topic, perhaps we can get some ideas from the community about how to ‘house’ your new diy instrument… partly as its an area thats frustrates the hell out of me !

so background, Ive a ton of ideas for instrument creation, and Im confident on the electronics side, and the coding side - BUT creating a housing, a form for them to live in - is what stops me doing it at all…

the form factor of an instrument is really important,
not only practically - your electronic (etc) need somewhere to live.
but also aesthetic and feel are important… a box is not that inspiring.

But living out in the wilds, I don’t have quick access to shops, and I don’t have a lot of materials on hand to use for the process … if I have to go ‘shopping’ for bits, I just loose inspiration/motivation. so it doesn’t happen.

and even with ‘chuck in a wooden box’, I never have the right size, or materials to create even a simple box.

so how do you tackle this?

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(I thought, Id the first post, frame the question… rather than my thoughts/ ideas)

but lets now dig into one possible solution… which Id love to get some feedback on.

3d printing…

so, I have looked (briefly) a few times at getting into 3d printing, as it would offer a solution…
once you have the printer/materials, you are good to for many form factors.

(you don’t need to go get different bits of wood etc… nor have the tools/skills to work them)

But I have some doubts…

I’ve had a few experiences with 3rd party 3d printed cases, and they usually, don’t look very good, and had de-lamination issues.
I’ll also admit, Ive seen alot of people get into 3d printing, but never really do anything with it… but perhaps, as I do have a solid use-case, this won’t be so much of an issue.

BUT, this was quite a while, and I don’t have first hand experience, so I guess the question is:

are there better materials and/or printers these days, that yield better quality prints?

what would you recommend, if you were starting out today?

both printer and filaments, and also at different budget levels.
(i.e. an entry level, but also something a little bit up from that, to get a bit more quality)

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ok, another option… but I think is too expensive.

laser cutting

Ive had somethings made up that were laser cut, and they were great.
it can cut thinner wood, and also perspex.

is this viable for a hobbyist … or just too expensive?

fab labs

ok, I know for some, they will say use a maker lab, but thats not viable for me… too far away,

similarly, I know I can get things made up, but that doesn’t work well in the initial diy phase.
since I have to wait about 2 weeks (slow delivery here) for things to turn up even if they offer next day delivery.

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Have dabbled with CNC machining and 3d printing lately (we have a 3 axis CNC in the Makerspace and I got a belt 3d printer now at home that can print quite large stuff).
In this case not only the housing but essentially the full instrument is printed (It’s a “poly expressive” but not electronic wind instrument: http://polymoe.org/)
Think there is also a lot of psychology involved. A high level wind instrument player is used to look down on “plastic toys”, a golden flute is considered much more awesome than a silver flute etc. Even if blind tests with recreations of historical instruments have shown that it makes no difference when using high quality material at least to the listener (it’s the air column that vibrates for wind instruments to the most extent, not the hull material…).

So long story short - at least for this scenario I think going with wood (and thus CNC) for the final instrument helps to be taken serious…
But 3d printing is really great for prototyping!

Regarding recommendations:
If you consider a CNC for home use for smaller parts perhaps have a look at the Carvera - it’s still 20% off atm.

The belt printer I have is great (iFactory3D One Pro) - but it got almost twice as expensive now - and I would honestly wait a few months to see how the company develops before going “all in”.

Belt printers print at 45°, so many things from Thingiverse&Co won’t work out of the box and need at least a slight redesign. (Doesn’t really matter for own stuff).
The up-side of belt printers is that you can technically print infinitely large in one dimension (or N times the same without manual intervention - which most people use it for, but that’s not so interesting to me)

The other recommendation for “normal” 3d printers would be the Prusa printers - have only heard positive things regarding print quality and support.

Regarding material: PETG is quite sturdy, not too expensive and easy to print - imho a good starting point. (And it can be food grade which can be important for musical instruments. But there are a lot of other aspects to consider, here a good overview video.)

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yeah, my closest maker lab is about an hour away (one way!) , and even that one seems pretty ‘limited’ in its tooling - so, its not really viable for me.

CNC , looks fantastic, but even at 20% off, $4k is over my budget :slight_smile:

but, the same goes for your iFactory3D One Pro !

which does raise the question - what budget is required for a 3d printer thats ‘semi decent’…
as there is no point in buying something that whilst cheap, is producing something unusable to me.
… is there a sweet spot, or just the fact… decent tools are always a bit pricey?!

I do agree with your premise…

perhaps its wise to split prototyping from finished product.

for a finished product, I think probably wood is easier/cheaper to get really good quality finish.
(assuming you have the skills, and some decent tooling, and time !)

also, of course, sometimes the case is part of the sound…
… so if you want to create a resonator, your going to be using wood.

so, indeed, 3d printing is (hopefully) quicker for prototyping.
but perhaps as a hobbyist that prototyping is ‘good enough’ , if at a slightly higher quality level.

I don’t care about being taken seriously :laughing: , this is, for me about home creations.
so yeah the psychology part here, for me, is about giving a physical form to something I can do electronically…
though perhaps, if I come up with some something I really like - a phase 2, could be using different techniques to get to the next level quality/feel.

also as you say, its not just the case… the other issue is also ‘fittings’ , e.g. how to attached pieces/pieces into the case, or dealing with ‘odd shapes’ … this is also where 3d printing helps.
e.g. when Ive used laser cut pieces, you need to start using stand offs, and screws… and I never have the right size available etc etc.

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I wouldn’t have bought the One Pro at the current prices either - they mainly seem to focus on B2B now…

If 25×21×21 cm is sufficient then I think the Prusa i3 MK3S+ is still high in the recommendation list. It also got more expensive recently but not as extreme as the One Pro. And they have a less expensive kit version for self assembly.

If you have the space (and don’t mind the dust…) there are less expensive CNCs on the market (without automatic tool changer, laser etc.) E.g. the Shapeoko 4 is below 2k€. Or a used one? (There are also much cheaper ones from China - but these might need manual tuning and parts replacement to get them working well). These machines are also more for wood and perhaps still aluminium, not for steel.

Then there are the Snapmaker machines, which are CNC, laser and 3d printer in one. Looks promising (have no personal experience). (The Artisan is more expensive, but the 2.0 machines also still seem to be available)

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hmm, the Snapmaker does look interesting…

(though, going for a previous product release, after a new one is alway questionable, in terms of longer term support etc)

good point about sizing, generally Id think 30cm3, perhaps 25cm3 would be fine.

I had a quick look a the forum, where they were discussing pricing of the Artisan (around 3k).

some were saying you could buy a 3d printer, laser cutter and cvc for around 3k, as separate units… and they would tend to be a bit better and faster.
(Snapmaker = jack of all trades)
so perhaps the Prusa plus a laser cutter, may work out better for me?
not sure I want/need cnc… but then again, Ive not used one before, so perhaps I do :laughing:

separate has advantage, that I also don’t need to get all at once.
that said, all in one is less space, one bit of software to learn etc.

so seems, what I need to do is
a) decide on size (I knew this was a factor)
b) think about budget
c) if I decide 2-3k, decide if its better to go all in 1, or separate

interesting… definitely feels like the whole field has moved on a lot from when I last had a look at it.

edit :
btw, I briefly remember seeing at some point, some 3d printers allowed camera attachments (?), so that you could do 3d scanning.
is this possible? … and frankly, is it even useful…
feels like the 3d scan would yield pretty poor results, but perhaps might help ‘guide’ the creation of models… I don’t know, something like ‘tracing’ paper to draw over?

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Regarding 3d scanning this video might be interesting (German, automatic translation is available though) - he is testing a (edit: not actually so) low budget 3d scanner, with very mixed results (it only worked well with the pre-provided demo object…).

We have been using an Intel 3D depth camera (<1k€) last year at work. There it was more qualitatively - for getting additional depth information when monitoring wheat growths). It worked okish for that scenario but I wouldn’t expect millimeter precision…

From what I’ve heard good machines start more in the four/five digits area (e.g. Artec Eva/Space Spider).
But I haven’t done too much research what is available in between.

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From what I heard most people migrate away from the Snapmaker software Luban pretty quickly. At least in the past (perhaps it got better)? (Edit: I just saw that Luban is Open Source (now?) and under heavy development - so it might make sense to keep an eye on it!)
So getting familiar with a dedicated CAD(/CAM/slider) might make sense in any case. (And you can do that without any machine :slight_smile: )

CAD
To make vendor lock-in particularly with free-commercial software less severe it is imho important to check that particularly these tools can export STEP files (a standardized file format that retains precise geometric information and just drops the construction history - so these files can still be edited with programs with direct editing or construction history reconstruction capabilities. Added corresponding notes which programs can export STEP and are good to edit them.

In the open source world there are

  • FreeCAD as UI program (with STEP export, no direct editing (yet, WIP))
  • and e.g. CadQuery (with STEP export, some direct editing)
  • and OpenSCAD (no STEP export, no direct editing) as text based, programmatic solutions.
  • Then there is Blender - even though it is still a polygon-based modelling, animation and rendering software at heart, a number of people also use that for precision modelling these days. (They boot into Blender and do virtually anything there :P) (no STEP export - but Blender mainly does polygons anyways, and mesh-formats like obj are supported. Only mesh based direct editing)

These tools are quite capable, have grown a long way in recent years, but some still also have some quirks (particularly FreeCAD and CadQuery, which use OpenCascade - with great power comes a great potential for bugginess). But one can work around these - and a lot can be achieved with these tools nowadays. (And to be fair - the commercial tools are also not bug free. Almost all commercial CAD software is using one of the two major commercial CAD kernels (Parasolid and ACIS), which shows how difficult it is to write one. In this light OpenCascade is a marvelous achievement!).

Good thing with open source tools - one isn’t dependent on the mercy of companies’ potential bait and switch tactics. (Some of the initially free offers got more and more restricted or revoked, in some cases with rather hobby-unfriendly prices for the commercial counterpart. Not so nice when one has many files locked into such an ecosystem).
The usual open source caveat - as a developer one gets easily dragged away from what one initially wanted to achieve, to work on the tool instead of with it…

Then there are (currently) free (or in case of SW low-cost) variants of commercial tools (for non-commercial use).

  • Onshape (web based, all documents are public in the free version, imho very well thought out! Has STEP export and basic direct editing)
  • Fusion360 (cloud based but with client, includes a capable CAM - but has some limitations in the free version, like only 10 documents activate at the same time, restricted export, CAM has no fast forward paths etc. Has STEP export (again, after some backslash…), basic direct editing.)
  • Shapr3D also has a free version - but it unfortunately limited to just three documents (Shapr isn’t using a construction history but “direct editing” - just drag stuff until it fits. No STEP export, good direct editing)
  • Solid Edge Community Edition (only for Windows) This is almost unrestricted, the caveat is that one cannot load the community files in the commercial version (so one has to start over in case one goes commercial). And each new release times out after three years. So one has to hope that the Community Edition is continued for a long time…), The neat thing with Solid Edge is that it supports both the classic construction history based approach as well as a special variant of direct editing (called synchronous technology there) - which not only allows to just drag things to change them but also to add absolute dimensions and constraints to any (e.g. imported, history-less) geometry in 3D that then get resolved. Has STEP export, great direct editing (which also works with smart dimensions) and history reconstruction.
  • Solidworks for Makers (only Windows): A hobby version of Solidworks for a low monthly/yearly rental. The same restrictions apply as for Solid Edge CE - only for non-commercial use, the files cannot be loaded in the commercial version and one never knows how long the service is offered. Comes with CAM. Initially saving was only possible in the cloud, but this was changed, so local saving works now. Has STEP export, allows history reconstruction and direct editing.

Some honorable mentions (commercial but in a still hobby-compatible price range; can be used commercially):

  • Moment of Inspiration 3D (MoI3D): Inuitive precision surface modelling. It is easy to get good results. The drawback is that it’s neither construction history nor direct editing based - changing things in retrospect is a little more difficult, one should better have a plan from the start :slight_smile: Has STEP export, very limited direct editing.
  • Plasticity: a little a hybrid between Shapr3D and Blender - more geared towards creative use. Precision modelling is not the main focus atm. Currently this is available as free beta. Has STEP export, great direct editing.
  • Alibre Atom3D (only for Windows). An inexpensive, classic CAD program that is still available as perpetual license (buy once). It is the little brother of the more expensive Alibre Design, but a lot can already be done with it. Has a more streamlined UI than FreeCAD, is more stable, has less features, is not open source, (but commercial support can also sometimes be nice) Has STEP export, direct editing
  • DesignSpark Mechanical (only for Windows): A slimmed down (but very usable) version of SpaceClaim, a CAD tool that completely focusses on direct editing. There is a free version which is mainly missing STEP import. This can be enabled with a low cost subscription.

CAM

  • the only open source CAM I know of is in FreeCAD. It’s 2.5D mainly today. 3+2 axis is in the works. Has path preview but no carving simulation (to get an approximation of how the result would look like)
  • Fusion 360 (as mentioned above). The commercial version is only available as subscription, the free version has some restrictions (like no fast path, as mentioned). Very capable and relatively easy to use. More sophisticated features are even not in the normal subscription but in the Machining Extension which costs 1k€/year
  • Deskproto: Rather hobby friendly prices, even for the commercial version (but there is also a hobby version at one forth of the full price). It is quite capable for a not-too-expensive CAM (e.g. four axis paths and even 3+2 axis paths)
  • VCarve: Different versions with the smaller ones being rather affordable. Easy to use, good for woodworking (one can e.g. cut large pieces into smaller parts that can be milled individually and then assembled)
  • NC Shop Floor Programmer. A 3 axis version of DELMIA that comes with Solidworks for Makers. Delmia is a high end CAM, so SFP it’s a little unwieldy even in this reduced version.

Slicers

  • Cura - open source; many options, there are versions that support belt printers (initially from Ultimaker)
  • PrusaSlicer - open source, high quality, (from Prusa)
  • IdeaMaker - free to use (but not open source), (imho) nice(r) UI (than Cura and even more options), supports belt printers (from Raise3D)
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I think the first question to answer before designing an enclosure is the intended quantity that you want to make.

+1 vote for Onshape. It’s really well designed and free to use as long as you’re OK with your CAD data being publicly accessible. IMO that’s fine for most hobbyist applications.

If you don’t own a printer, I highly recommend JLCPCB 3D printing. They have a really awesome resin process that’s very cheap (8111X material is my favorite). The only issue is the shipping cost starts around $50 (to the US), so only worthwhile for projects that you’re already sinking hours into.

Here are some examples of their quality:

For laser cutting, you can order parts from Send Cut Send. Again, it’s nice to avoid the hassle of owning the machine and just paying a bit for parts when you need them.

If you want to make enclosures in quantities from about ten to a few hundred, bent and painted sheet metal becomes a good choice, like the Make Noise 0-Coast. I hear that protocase is a good vendor for this but I haven’t tried them yet myself.

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Good point, sending in the cad file and getting the result back can also be a good option - particularly for high quality final results!
I would just be too impatient during prototyping :stuck_out_tongue: (That said, for a case one usually doesn’t need as many iterations as for an acoustical instrument that needs lots of fine tuning to sound (first at all and then) good).

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True, but in a similar vein people are used to waiting 2 weeks to get their PCB iteration back. You just need to be a bit more careful when releasing a design. A good strategy is to turn on the cross section feature in your CAD program and slowly sweep through the design in all 3 directions to do a final check for interferences before releasing

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It would be cool to have a CFD system that is realistic enough that it could blow into the model of a wind instrument and compute the tone that is getting out. That would save a lot of time and filament. Not too big of a target audience though, if this would exist I fear I couldn’t afford it…

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I know nothing about this very interesting topic but I do have a DM48 from Lekholm instruments, which is a midi harmonica and was 3D printed I’ve had it for years, never had a problem, it’s solid as a rock and it looks great! I got some knobs recently from ParksTools with what looks like a much cheaper housing which the bottom fell off after two goes.
I will follow this topic with interest. Power to your elbow.

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thanks for all the suggestions … its a very interesting field.

my fear though is one which I think has stopped me proceeding in the past…expense…

Im getting caught a bit in that loop, where you start looking… thinking a budget of (e.g) $500 will be fine, but then the more you look, research, you start looking at $2-4k tools :eyes:

in fairness, this happens a lot with me when I get start on something new.
I, generally, dont like buying ‘cheap tools’, they feel like a bad investment, a limitation.
but of course, the flipside is… as a newcomer, you also don’t need the best.

so getting that ‘sweet spot’ when starting out is tricky.
… and of course, this leads to me procrastinating, and doing nothing.
which I kind of feels is where Ive been, generally, with this area.

of course, this just really means, I need to ‘make a decision’…
I think either:

a) go for it - spend the 3k, get an all in one
its far from perfect, but would get me going… and provide no excuses!
b) build it slowly,
grab a 3d printer, Prusa i3 MK3S+ Kit looks fine… play with it, build some stuff, then see if I still need a laser cutter.

common sense (and my wallet) says (b) is the wise choice… although even the Prusa kit is nearly 1200 euros (with enclosure)… which is still a bit more than I was expecting.

perhaps I should invest in some wood working tools :laughing:

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Personally, I’d start with wood for prototyping and working out basic designs. But then I already have some woodworking knowledge and skills plus basic tools (Table saw, pull saws, chisels, carving knives, drill and drill press, sander, Dremel, clamps). You can kit out quite a capable set of tools for much less $$$ than a single CNC, laser cutter, or 3D printer. Some of these you will also need in any case.

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I recommend getting a Prusa mini to get started, having a printer at home is nice to do a lot of quick iterations while you’re learning. The print volume is a little limited at about 175mm cube. But I think you can still utilize the printer while learning to test out your ideas, then when you need something really big order that from JLCPCB 3d printing

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The Prusa Mini sounds like a good choice, if the size is sufficient for the planned projects.

Some even cheaper+larger printers that got generally favourable reviews as solid entry choices:

  • ELEGOO Neptune 3 Pro / Plus / Max for $230/$350/$470 with a build volume of 22,5x22,5x28 / 32x32x40 / 42x42x50 cm^3.
  • The Sovol SV06 /SV06 Plus() with 22x22x25 / 30x30x34() cm^3 for 250€/300-400€(*)

Has anybody personal experience with any of these? (*: Well, probably not the Sovol Plus as it’s not out yet :slight_smile: )

Edit: Interesting videos:

From what I heard bigger isn’t always better when it comes to 3D printers - the bigger they are, the sturdier they have to be to prevent dimensional inaccuracies - one of the reasons why big industrial grade printers are so expensive. And things like bed heating etc. take longer. So putting some thought into how big the printer really needs to be might pay off both financially and quality-wise.

Starting with woodworking sounds promising! What stopped me going this route is the lack of a workshop - doing woodworking in the living room might be a little messy :slight_smile:
But if this is available, it’s (from what I heard from family members) a lot of fun - and a diversion from the computer monitor :slight_smile:

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Just looked around a little yesterday again, I’m apparently already not up to date anymore. New, much faster printer seem to be available by now (e.g. the new ones from Bambu Lab, FLSUN etc.). These are said to be up to 3-4 times faster than the “i3” generation at comparable quality(?). I fear people wanting to buy a 3d printer here and now might have to do their own here-and-now investigations :slight_smile:

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yeah, I think this tech is moving fast :slight_smile:

I can definitely see how size could result in poorer quality (in same budget area) , as you say reduced rigidity, and precision.

so indeed, I think I need to think about what size do I really need… and perhaps I can get away with a smaller bed, and be more creative with prints (e.g. multi part) , of even doing a hybrid design…
so using wood for ‘large’ flat areas, and just 3d print things like mounts/connectors.

woodworking, yeah I don’t really have a good space to do this currently either… and would need to invest in both tooling and materials.

I do have some woodworking tools… but they aren’t really for fine details, they are more ‘furniture scale’
e.g. my circular saw is fine down to (say) 2-3mm precision and thicker wood, but is too bulky to get accurate enough for small enclosures. … same with things like my clamps/sanders.
of course, Im sure those with more skills would be fine… so in part, its is my lack of skills as well.

( its this lack of precision that made laser cutting attractive !)

also critically, Id need to have a decent workbench, with vices etc… and not got room for that currently.
perhaps when I move my solar system over to lithium batteries, as that will free up quite a bit of space :slight_smile:
(but thats a few years away still, as current batteries are still performing well)

but definitely sounds like I should look at this from a few different angles.