A Common Issue

Throughout our entire season, we have had one particular issue among our robot, particularly being noticed and/or occurring at competitions. So we have been using a Six Bar Lift and it seems whenever we come home from a competition and begin inspecting the bot, the axles holding the lift are completely twisted or warped. I will provide pictures of what our axles look like when twisted. Is there any way we can prevent this? It ruins the efficiency of our lift and damages, as well all know, expensive axles. Although twisted axles are common, it seems something else that may happen that is related to this is that the gears are stripped. And so the axle is just slipping through the gear instead of being pushed. Does anyone know how to fix this?


You could try using high strength shafts .

That’s why we’re known as Twisted Axles

We have actually tried this and that caused the gears being stripped out on the inside. It didn’t help much.

It sounds like you’re either: running motors in opposite directions or putting waayyy too much load on your gearbox. Could you maybe post a pic or two of your gearbox? Also make sure your motors are running in the same direction.

Robosourse.net has high strength locking bars. https://www.robosource.net/38-hs-lock-bars

These are made by a Vex team from vex metal. We have a bunch of them and they are great.

Twisting happens more often when axles are very long. You may want to change your design to keep the distance between the drive motor and the lift mechanism short.

Stripped gears can also happen with long axles because the axle flexes allowing the gears to skip and break teeth. Having a compact assembly with bearings prevents that from happening

An easy solution would be to line that shaft with steel pinions, that way they are better supported across the length.