Board Thread:General Nerf discussion/@comment-26431461-20190529022825/@comment-27306930-20190620225821

Unfortunately, it does matter how thin the part that holds the axle is. At first glance it might seem like it just rotates freely around the axle. But in this diagram, any force in the Ft turning direction is going to have Ft force on the axle in the opposite direction, assuming the receiving gear is located on the opposite side. The axle is actually "transmitting" the force from the supply gear to the receiving gear, through the axle.

It's an easy thought experiment. If you had three gears meshed in a straight line from top to bottom, and there was no axle in the middle gear, would the bottom gear rotate when you turn the top gear ? Or would it just push that middle gear out of the way ?

It gets a little more complicated when the gears aren't in a straight line, but let's not go there right now.

Bottom line, you would need to seriously strengthen the bushing in the center of that replacement gear. If it's hollow, then epoxy putty might be useful to fill in the voids and make the gear solid, for all intents and purposes.

Sorry if I rambled a little 😊