Custom Gearbox is very loud

[GeeTwo]

Originally Posted by Tottanka

The loud noise seems to come from the gear that attaches to the CIM pinions (2 motors go to one VEX 72 teeth gear).

We had a different set up, but it sounds analogous. We were able to quiet a TB-mini simply by removing a CIM, turning it 180 degrees around its axis, and re-mounting. Shouldn't make a difference, but it did. I would try mounting each motor separately and in both orientations to see where the binding is occurring. If you have binding all over, you may need to increase the spacing.

Edit: this happened to us twice with different gearboxes and plates in different years. I can't prove it was the same CIM in both cases, but I wouldn't be a bit surprised if they were.