Carbide 3D belt tension accessory

[Steve.Mc (Steven McGeorge)]

It could use a little touch up on the design, but it works. I used two m3x18 boots to clamp the two parts together, and a M5x25 bolt for the tensioner.

[ProfessorEcks (Jon Eckels)]

Thank you for posting the photos. I had a feeling it would rack a bit due to the offset pulling forces. Glad to hear it’s working!

I’ve never 3d printed anything. Will the plastic hold long term, or will it relax or warp over time under that tension?

I’ve been working on a thumbturn-style tuning design for the belts on my machine. Haven’t cut it yet but seeing your design has helped.Thank you very much for sharing

[neilferreri (Neil Ferreri Ω)]

@ProfessorEcks

Will the plastic hold long term

I think it should hold fine. Unless you subject pla to high heat, you should be good. I’ve never seen petg warp after the initial printing. I’ve seen 3d prints under much more strain than this and they hold up great… Especially with no moving parts.

Got an idea to prevent the offset forces? The screw just has room in the hole to tilt.

[ProfessorEcks (Jon Eckels)]

@neilferreri

Got an idea to prevent the offset forces? The screw just has room in the hole to tilt.

I’ve been playing with designs for this that put the pivot point up high, with a thumbscrew somewhere in the middle of the pivot for tension. The bottom holds the belt against or near the rail. This requires adding an extension backstop to the 1/2” thick front plate, so the upper area has something to mount or press against. I’ve gone through several designs but I haven’t cut anything yet so nothing practical tested

Some drafts in the picture below. Originally i was thinking the top had to be a mechanical pivot but more recently i’ve been thinking that this might be achievable with a sandwitched plate that slides as it’s tightened. In both of these I’m not using the hole in the front plate for the tensioning screw, I’ve got another hole above it. I’ll probably use that hole instead as a locating hole for the extension.

Probably far more complicated than this idea deserves, but i really want to be able to tighten with a knob or thumbscrew. I’ll probably use a locking nut behind the thumbscrew, which isnt shown here.

[neilferreri (Neil Ferreri Ω)]

@ProfessorEcks

Probably far more complicated than this idea deserves

Essentially the same idea… Use a screw to pull something holding a belt.
I have some M5 thumbscrews that I thought about using, but with this machine being around a lot of people I don’t think I’ll use them. Thumbscrews ask to be turned by anyone that sees them.