I have an old small gear that somehow got flattened to an oval shape. The axle hole is too narrow to slide a bar through, although it is not completely closed shut. How can I repair this gear?
I'm building a (what I hope to be) high-speed car using two PF-XL motors together and some gearing up. However, there's a point where I have to rotate the axle with power (that comes from the 3 speed ...
I need a mechanism so that if a (NXT) motor rotates forward, it moves one gear, but the other stays still, but if it rotates backward, the first gear does not move, but the second one does. I found ...