Worm Gear question

Does anyone know how to determine the load capacity of a worm gear system, or just how much weight a worm gear system can hold/carry? Do worm gears typically have high load capacities?

They aren’t typically used for most competitive teams. They’re a relatively rare part at most competitions so data should be pretty hard to find.

I believe that worm gears generally do have a higher strength than normal gears, although that probably varies from system to system depending on how well it is constructed. But like @NicolBolas said they aren’t often used in vex because it’s rare you need such a torquey gear ratio, and there are very few instances where gear strength is a concern.


This can be more important with worm gears though, since if you are lifting something that you need a worm gear for, all the force will go on the threads of the worm gear, not on the motor like in normal gears.

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In vex, if your mechanism requires so much torque that you need to use a worm gear, the gear will break before maximum torque is applied.

There’s an easy way to find this torque: Set up a stationary worm and gear and pull a bar of a known length with a spring scale. The last value shown on the spring scale before the gear breaks is the maximum force in inch-pounds.


from my somewhat limited experience with worm gears, it’ll usually start skipping before it breaks. I tried using it to wind up string, with the string pulling the worm gear against the other gear, but it still bent the other way and skipped before any of the gears could break.


I had this problem too. The gears skipped before we got anywhere close to breaking

That being said… gears do still break

This can be minimized by making sure your bearings are close to the gear.