high torque screwdriver head

While I like [thing:3093890](https://www.thingiverse.com/thing:3093890) and [thing:526286](https://www.thingiverse.com/thing:526286) quite a bit, they are small and can't get a lot of torque on a screw, especially if it is stuck. I could have used a conventional screwdriver, but most of those either don't have a large enough diameter handle, or they are uncomfortable under high pressure, or both. I could use an electric screwdriver, but frequently with stuck screws, these don't give a good feel for what is going on and it is very easy to strip and grind out the head, making it impossible to remove the screw by normal means.

So I tried to make a bigger screwdriver head. Unfortunately, under pressure it either distorted the plastic or the bit just spun in the head. The solution was to add a cavity to the head and fill it with the strongest epoxy I could find (J-B Weld Steel Reinforced strength 5020PSI).

This has worked well in my testing so far.