[FTC]: Using TETRIX work gear assembly.

[PhilBot]

Hi

Do'h.. The title should read WORM Gear, not work gear....

anyway.....

We just started using the TETRIX worm gear assemblies this year.

Worm gears are great for producing compact high gear-ratios, and they can't be back driven, so they seemed a great choice for an arm gear drive.

However, we're finding that the coupling between the brass worm gear (not the worm, but the gear) and the main axle is not particularly robust.

There are two set screws for holding the axle in place, but these seem to come loose at the drop of the hat. Granted this is a high torque point, but even still.

After many attempts just to tighten them, we moved on to using blue lock-tight (We don't use red any more... long story). Even with this, and ensuring that the screws are set on the flat, after some moderate use the shaft is slipping again.

Is this a lost cause?

The torque requirements aren't huge. We are using the 4:1 worm. followed by a 2:1 gear reduction, and the arm move quite quickly under full power. We have prevented running the arm into stops at each end so there is no huge stopping force involved.

At this point we're considering epoxying the axle to the gear, and making the entire gear/axle/channel a single replaceable assembly. (since there would be no way to remove the gear/axle at that point).

We know how to get a similar reduction using gears or sprockets but just thought it was worth a try with the worm.

Any magic insights available?

Phil.