So, just to get this right...
There is the disc, the hub, two pulleys, a few bolts and bushings.

It seems the hub and one pulley are made from one part (is there any problem with making them from two parts? guess that would be easier/cheaper), while the disc and the other pulley are placed on that hub, and then squeezed together by the bolts. Bushing into the inside of the hub, and ready to go?
So the hub basically avoids the needing of a tube-part where everything is fixed on and the bushings come in, right?

So we have two kinds of forces involved when the disc hits:

1. the disc suddenly stops, potentially sheering off the bolts when the momentum of the pulleys (and the motors) want to keep them rotating, but the disc can't. This will be countered by the clamping of the disc between the pulleys, so the force will be distributed through friction more than just the bolts in the way. (should the hub be just a tiny bit shorter than the disc is wide, so i can really tighten those together?)

2. the disc wants to go down while the enemy gets send up, potentially bending the axis.
This will be countered by the hub with the bushings sitting tight on the axis, which is as short as possible so those forces don't get much leverage.

Somehow still unsure about this, sorry... can't seem to get the hang of this concept.

Is Ali as material for all those parts okay, or should the hub be from steel?
The way i would do this would be to just get two Ali discs and an Ali tube, and throw them in the lathe to make two pulleys and one tube that should fit tightly inside the pulleys and disc as well as having bushings fit inside it. So... after all, the hub is something to hold the bushings in and distribute the second kind of forces from the disc to a wide part of the axis? (guess for that last task it should be steel, not Ali then...).


On a second similar issue:
Since i will have to use belts for the drive train now, too...
Any ideas on what would fit there?
Pulley width is an absolute maximum of 10mm, really can't fit more in there.
8mm would be better, but not sure if that is enough for any usable belt.
Also wanted to make those pulleys from HDPE, since it's lighter, i could make pulley and wheel from one 20mm thick disc, and i believe those don't have to be as sturdy as the weapon system. If just a HDPE-wheel direct driven on a gearbox works, HDPE-pulleys should be just fine, right?



A lot of possibly stupid questions, just want to make sure and not causing any avoidable problems on these important parts.