New build.Stell frame cnc 1500X1000.Ball screw and gearing calculations

[JAZZCNC]

Option 2 would be best in this case but you may find locating 15mm pitch screws difficult and expensive.?

#1: Really You don't need the upper tensioners just make the Motor adjustable to tension belts. But yes it would work.!
#2: 15mm belt width will work fine.
#3 Sorry no I buy local.
#4 Yes but much higher than 1500rpm . . Think about Timing belts in Car engines.!!
#5 Can't see why it should provided the tension and alignment is correct, most common cause of belt failure and premature wear is incorrect tension or alignment.
#6 Aluminium will reduce inertia on ballscrew but wear quicker than Steel but again if correctly tensioned and aligned then not an issue. I've had aluminium pulley on my machine for over 5yrs and it's still fine.
#7 See above but Like I said before 2:1 with 10mm pitch will be fine I tell you this through lots of experience not theory.!!