[waialua359]

we are familiar with your problem since we encountered the same problem about a week and a half ago. The taigene worm gear inside is all plastic and fine, thus unable to hold in place.
Our solution was two-fold. We used a larger gear ratio to pivot our arm and used springs and frame stop points to smooth the flow.
The main thing is design. Our design eliminates the problem of whether the arm can move or not once a load is present. It doesnt matter for our robot.

The same thing will happen with the window motor, however a double step reduction eliminated any arm movement problems on our second joint. The double reduction eliminated the need for such a huge sprocket at the top of our arm joint, keeping us within design dimensions.