Final drive speed is a concern for a 4 axis hotwire foam cutter. It needs to be fast enough to not excessively melt the foam.
I think I'll be OK, won't know till I've built the rig. I haven't bought the threaded rod yet. I could do the math (thread count, max rpm), I think I will just cruze along and see how it turns out. It will be like a suprise, aren't suprises fun, well hopefully!

Cheers