This is a custom pulley design to keep the string from slipping off too easily. It is specifically designed for the Tetrix 6mm Motor Hubs, found here. It's outer diameter is 45mm while it's inner diameter is 21.6mm. The fully assembled pulley from one end to the other it is roughly 35mm across. Those involved in the First Tech Challenge will find this model especially helpful.
Designed by the FTC team St. Stephen's Technospartans 7975
Print out both "pulley.stl" and "pulley with string anchor.stl." This will give you two "halves" of the pulley that can be put together with the Tetrix 6mm Motor Hub, found here. One of the halves should have an additional hole in it, which is where you anchor the string.
Attach a half on either side of the Tetrix Motor Hub with screws.
- You can use the string anchor by inserting the string down the proper hole and tying a knot to prevent it from slipping back through.