Tumbler speed/torque control
thingiverse
This setup applies equally to configuring my Tumbler, which is also posted on the website http://www.thingiverse.com/thing:981501. Use both pulley systems (drive and motor) to manipulate speed in relation to torque, allowing for control in any manner, including speed regulation.
Download Model from thingiverse
With this file you will be able to print Tumbler speed/torque control with your 3D printer. Click on the button and save the file on your computer to work, edit or customize your design. You can also find more 3D designs for printers on Tumbler speed/torque control.