Perfect Pin for JamesWhite's Seahorse Gears. Just press into place. They are tight enough that they won't wobble or come out. You may have to ever so slightly drill out the "eyes" on the seahorse gears. Just test fit it first to make sure it's necessary. Print it on one of it's flat sides to give it proper strength. I should also mention that I've only tried this with ABS. I set up everything to print out in one print job. I used 0.15mm layer height, 2 shells, and 50% infill. Remember this is meant to fit tightly through the arm holes. Occasionally a hole will print a little smaller than the others and it's necessary to lightly twist a small file in the hole to widen it. However, if you need to do this, do it just barely enough or the pin may end up too loose. The pins should be tight enough that you need to push them in with the aid of a strong flat object such as a table top. If you've widened the hole to the point you can push it in with only your fingers, it's probably too loose. I hope it works out well for you!