10t XL Pulley for SAE Prusa Mendel

by BenJackson, published

10t XL Pulley for SAE Prusa Mendel by BenJackson Mar 30, 2011
5 Share
Download This Thing! Customize Order This Printed Tools & Utilities

Thing Info

7608Views 2154Downloads
Report Thing


The Prusa git repository does not convert T5 belt (5mm) to XL belt (0.20") when generating STL for the SAE version. The pitches are so close that the pulley appears to work, but the ratio of tooth to space is different so there is backlash when the pulley reverses as the small teeth slide in the large gap.

This is a variation of a 10t XL gear that Rick at MakerGear sells with his kit. His STL didn't print well for me due to slight printing inaccuracy causing the grooves in the pulley to fill up with material. This one is derived from an SCAD source here on Thingiverse. The grooves for the belt teeth are 25% deeper than nominal.

Rick's STL is on github: https://github.com/MakerGear/MakerGear-Prusa-Mendel


Print two (one for Y, one for X).

Drill out the hub to 5mm.

Insert a M3 nut in the base (yes, M3 even though SAE Prusa builds for #6 -- #6 is far too huge for a setscrew).

Recalculate your X/Y_STEPS_PER_MM as 200 steps/rotation 8 microsteps/step / (0.2 inches/tooth 10 tooth/rotation 25.4 mm/inch) = 31.496 steps/mm. Note that you must adjust this for XL belt even if you elect to use the original 8t pulleys because the distance moved is 0.2"8, not 5mm*8.

Thing Info

7608Views 2154Downloads
Report Thing

Liked By

View All


10t XL Pulley for SAE Prusa Mendel by BenJackson is licensed under the GNU - GPL license.

Give a Shout Out

If you print this Thing and display it in public proudly give attribution by printing and displaying this tag. Print Thing Tag

All Apps

This App connects Thingiverse with Makeprintable, a cloud-based mesh repair service that analyzes, validates and repairs most common mesh errors that can occur when preparing a 3D design file for p...

App Info Launch App

Kiri:Moto is an integrated cloud-based slicer and tool-path generator for 3D Printing, CAM / CNC and Laser cutting. *** 3D printing mode provides model slicing and GCode output using built-in...

App Info Launch App
KiriMoto Thing App

With 3D Slash, you can edit 3d models like a stonecutter. A unique interface: as fun as a building game! The perfect tool for non-designers and children to create in 3D.

App Info Launch App

Awesome! This fixed a bunch of issues I was having with my machine! I had no idea it was the belts!

This was one of my early openSCAD files, I apologize that it's not written that well! But I'm flattered that everyone makes such good use of it! :)