[Joey Milia]

Posting a picture and more information on the worm gear set up would defiantly be useful. For the worm gear to work well you need to support it really well, or else you'll end up with alignment and wear issues already mentioned. I don't think this is a high shock load application so a cast iron worm gear will probably work if you can't get a brass one quickly.

It would help to increase the reduction in the worm gear stage, instead of before it, using something like a 40:1 or higher because you'll be putting less load on the worm gear teeth.

Counter balance will defiantly help. Appropriately strong constant force springs would be ideal but surgical tubing can work well too and will probably be easier to implement.