Best filament for printing drive belts?
Hi!
I have been recently experimenting with 3D printing transmissions and gearboxes. Standard gears, cycloidal drives, etc. Now, I'm exploring belt drives. It is easy enough to design and print pulleys themselves, but the belts are an issue. Off-the-shelf belts are rarely the right length and width (at least where I live, the selection is really sparse, and ordering online from abroad takes months to ship).
For smooth belts (no teeth), I sometimes use weldable polyurethane tubes (like this), but even these don't always fit the design. And when teeth are required and no off-shelf belts are available, there's definitely a problem.
So I'm wondering if belts can be 3D printed too, using flexible or semi-flexible materials.
So far, I've tried TPU and PP. TPU is much too prone to plastic deformation - meaning, the belt stretches out very quickly, and does not return to the original length. PP seems a bit better in this regard, but it also tends to deform permanently, and due to it's hardness, it wears out the pulleys.
Additionally, both these materials are slippery, requiring more belt tension to get a good grip on the pulleys, which accentuates the elongation issue.
I wonder, what other materials could I try? Are there any flexibles / semi-flexibles that are less slippery (more like rubber), and also deform elastically, rather than plastically?
RE:
I cant help much for the belts, but if you do a youtube search for "3d printed chain and sprocket" you find a few designs similar to bicycle-chains.
It also all depends on the required tolerances for timing as there are much more slop in a chain then a belt.
EDIT: Ohh, i just remembered something about a rubber-filament printer that "Make Anything" tested a good while back as well.
Edit2:
Prusa Mini+ kit. BondTech extruder. FW 5.1.2
Prusa MK3S+ kit. Stock. FW 3.11.0
Prusa MK3S+, used. Stock. FW 3.13.3
RE: Best filament for printing drive belts?
I cant help much for the belts, but if you do a youtube search for "3d printed chain and sprocket" you find a few designs similar to bicycle-chains.
It also all depends on the required tolerances for timing as there are much more slop in a chain then a belt.
EDIT: Ohh, i just remembered something about a rubber-filament printer that "Make Anything" tested a good while back as well.
Yeah, I know these chains. But they are very loud, and difficult to make on a small scale... Interesting idea, but I don't see them replacing timing belts, unless for very large builds.
Addressing your edit - what filament was that, exactly? Perhaps you have a link? 🙂
RE: Best filament for printing drive belts?
I found the video, linked in the post.
It was Atomstack Cambrian Pro 3d-printer. http://atomstack3d.com
Prusa Mini+ kit. BondTech extruder. FW 5.1.2
Prusa MK3S+ kit. Stock. FW 3.11.0
Prusa MK3S+, used. Stock. FW 3.13.3
RE: Best filament for printing drive belts?
I found the video, linked in the post.
It was Atomstack Cambrian Pro 3d-printer. http://atomstack3d.com
Interesting. I always thought that rubber cannot be 3D printed because once vulcanized, it cannot return to a liquid state... But in any case, maybe I'm missing something obvious, but what is so special about that printer that makes it possible for it to print rubber? It is direct drive, same as MK3S, the temps for the filament are the well within MK3S ranges, so... What is different, apart from filament diameter? I'm wondering if MK3S could handle printing this filament, if I could source a 1.75mm version of it.
RE: Best filament for printing drive belts?
if I could source a 1.75mm version of it.
I think the secret sauce is in the 2.85mm thickness. Perhaps making it stiff enough to print.
I'm just speculating here tho.
If i remember all belts are reinforces with either steel or fiber-mesh inside to eliminate stretching.
Stiff tpu/tpe/rubber will always stretch under load to some degree.
Prusa Mini+ kit. BondTech extruder. FW 5.1.2
Prusa MK3S+ kit. Stock. FW 3.11.0
Prusa MK3S+, used. Stock. FW 3.13.3
RE: Best filament for printing drive belts?
Ninjaflex
Regards
Swiss_Cheese
The Filament Whisperer
RE: Best filament for printing drive belts?
if I could source a 1.75mm version of it.
I think the secret sauce is in the 2.85mm thickness. Perhaps making it stiff enough to print.
I'm just speculating here tho.
If i remember all belts are reinforces with either steel or fiber-mesh inside to eliminate stretching.
Stiff tpu/tpe/rubber will always stretch under load to some degree.
Elastic stretching is not an issue... Issue is plastic stretching (when the part doesn't fully return to it's original shape after stretching).
Ninjaflex
Regards
Swiss_Cheese
Ninjaflex is TPE, correct? How is it different from TPU? Is it less prone to permanent deformation, and is it more rubbery in terms of friction?
Ninjaflex is a TPU it's durometer 85A it makes great drive belts.
The company that produces Ninjaflex makes several very high quality products for printing and so far I've had no issue printing them on my MK3 machines.
you can look the company up on the web and find out everything.
https://ninjatek.com/about-ninjatek/
Regards
Swiss_Cheese
The Filament Whisperer
RE: Best filament for printing drive belts?
Ninjaflex is a TPU it's durometer 85A it makes great drive belts.
The company that produces Ninjaflex makes several very high quality products for printing and so far I've had no issue printing them on my MK3 machines.
you can look the company up on the web and find out everything.
https://ninjatek.com/about-ninjatek/
Regards
Swiss_Cheese
Are you sure about this? I found this article describing how some folks have tried using Ninjaflex for belts, and found that this material stretches permanently and does not return to original shape...
RE: Best filament for printing drive belts?
I wasn't aware you were trying print rubber bands, you said "drive belts" to me that means like the one that drives my drill press or the one that drives my sanding station or my band saw, all floor stand industrial.
I would just by rubber bands if that's all your looking for, it's not me that has to be sure, it's you. you asked for recommendations and I offered my experience.
Regards
Swiss_Cheese
The Filament Whisperer
RE: Best filament for printing drive belts?
I wasn't aware you were trying print rubber bands, you said "drive belts" to me that means like the one that drives my drill press or the one that drives my sanding station or my band saw, all floor stand industrial.
I would just by rubber bands if that's all your looking for, it's not me that has to be sure, it's you. you asked for recommendations and I offered my experience.
Regards
Swiss_Cheese
Sorry, I didn't mean to sound ungrateful 🙂 I do want to print drive belts, not rubber bands. But these belts will be no good if they stretch out permanently and become loose...
RE: Best filament for printing drive belts?
Maybe you could try a compound belt, with TPU as the contact surface for better grip and a PC spine for more strength?