Do Linear Rails Perform Well Under Cantilever Loads?

Turbo

@fcwilt sounds like a fun project. Ever since I saw the Voron2, I've loved the idea of a belted Z axis, and it is really nice. No z banding to worry about assuming everything else it running smooth. Maybe consider what ive done and go belted. No lead screws to mess with

fcwilt

@Turbo said in Do Linear Rails Perform Well Under Cantilever Loads?:

@fcwilt sounds like a fun project. Ever since I saw the Voron2, I've loved the idea of a belted Z axis, and it is really nice. No z banding to worry about assuming everything else it running smooth. Maybe consider what ive done and go belted. No lead screws to mess with

I'm always up for trying different things.

How many belts? How many steppers?

Thanks.

Frederick

Turbo

@fcwilt two belts. One stepper, which is geared 5:1, and a large rod to sync them up.
Here's a section view of one side.

fcwilt

@Turbo

Interesting?

What size belts?

Where did you get that kind of stepper?

Part #?

Thanks much.

Frederick

Turbo

@fcwilt

Gt2 9mm width x 2. Dont know the exact length offhand
Motor part # --> 17hs15-1684s-pg5
*Link to motor --> https://www.omc-stepperonline.com/nema-17-stepper-motor-bipolar-l38mm-w-gear-raio-51-planetary-gearbox-17hs15-1684s-pg5.html

fcwilt

@Turbo said in Do Linear Rails Perform Well Under Cantilever Loads?:

@fcwilt

Gt2 9mm width x 2. Dont know the exact length offhand

Motor part # --> 17hs15-1684s-pg5
*Link to motor --> https://www.omc-stepperonline.com/nema-17-stepper-motor-bipolar-l38mm-w-gear-raio-51-planetary-gearbox-17hs15-1684s-pg5.html

Thanks VERY much for that info.

I may have to try this as it is unlike any other approach I have used.

Frederick

achrn

@Turbo said in Do Linear Rails Perform Well Under Cantilever Loads?:

@achrn @JoergS5 So what im getting from this is that so long as I'm off-putting the main load onto something else, and primarily using the rails just as an alignment factor, it's fine. Sound about right?

(I think you've already reached this conclusion, but...) From the 3D picture, and assuming the linear rails have replaced the four wheel carriage that's back central in that view, yes, I think that rail is actually carrying next to no loads in any direction - it's just stopping the platform swinging round on the belt. (Though it obviously doesn't swing free since the belt is restrained top and bottom). My initial understanding (assumption) was that you had the belt only on one side (i.e. as if the diagram shows the whole drive mechanism) - then there would have been a significant moment on the carriage.

fcwilt

@Turbo said in Do Linear Rails Perform Well Under Cantilever Loads?:

@fcwilt two belts. One stepper, which is geared 5:1, and a large rod to sync them up.
Here's a section view of one side.

Hi,

I've decided to go ahead and try belts of my Z axis.

Do you have any link(s) to more images or 3D models of your printer that I could look at?

Thanks.

Frederick

Turbo

@fcwilt It's not my design, but this was the designers printer before he moved and gave it to me. He also gave me the CAD files, so if you PM me, I'm sure i can email or discord you the related files.

Turbo

@achrn @fcwilt @JoergS5
Here is the 1st official print. 150% benchy, straight off the print bed. Needs some retraction adjustment but otherwise minty.
-0.3mm layer height -65mm/s print speed