This is half of a pulley wheel for a bicycle chain. Print two and glue together. I found printing the whole wheel required supports that left a surface too unfinished for the need. Fifth photo shows the two halves at the bottom, a glued together set in the middle, and a finished wheel with pressed in bearings at top.
Works with chains up to 12 speed, including SRAM AXS flattop.
The center of the wheel fits a 608ZZ bearing. I had M6 hardware lying around, so I printed spacers for those bolts, which is the other STL included. Two are needed for each wheel. (Note: a couple of the photos show the spacer without a lip. The attachment with the lip is needed, so the bearing doesn't bind against the board.)
Photo shows how to mount 3 on a board, and run a waxed chain through to loosen the links after the wax dries and hardens. You might consider bringing the top two wheels closer together. The closer the pulleys are, the more the links have to bend, which is the goal.
Printed in PLA with 0.2 mm layer height. Time will tell if the PLA stands up to the abuse…you may try a different material.
Bearings pressed in with Knipex Pliers Wrench…gotta give a shout out to one of my favorite tools, whenever possible! 😁
The pulley wheel is a modification of “SRAM GX EAGLE Pulley wheel” by @MP_2026695.
The author marked this model as their own original creation.