Starting point for a pick and place - cheapy CNC and convert or build my own?

[JuKu]

My take on your list:
1: I'm going for belt. My goal is better and faster than hand placement, and belt (GT2) is more than enough for that.
2: Agreed.
3: Cam, just because Zapp has a nice motor for that: SY17STH0404-200TR8X8-EX
4: I'll have extrusions bolted on table along X, Y shafts mounted on these, tapes coming in under the Y shafts.
5: At least as important is the driving algorithm. I think I'll use TinyG driver board (https://www.synthetos.com/webstore/i...cs/tiny-g.html). It has 3rd order acceleration, and allows customization of the software (I know how to program Atmel micros). TinyG and Nema17 motors are fast enough for me: https://www.youtube.com/watch?v=Om0w...feature=relmfu

[8086]

My take on your list:
1: I'm going for belt. My goal is better and faster than hand placement, and belt (GT2) is more than enough for that.
2: Agreed.
3: Cam, just because Zapp has a nice motor for that: SY17STH0404-200TR8X8-EX
4: I'll have extrusions bolted on table along X, Y shafts mounted on these, tapes coming in under the Y shafts.
5: At least as important is the driving algorithm. I think I'll use TinyG driver board (https://www.synthetos.com/webstore/i...cs/tiny-g.html). It has 3rd order acceleration, and allows customization of the software (I know how to program Atmel micros). TinyG and Nema17 motors are fast enough for me: https://www.youtube.com/watch?v=Om0w...feature=relmfu

Okay, so belt is good, and so are unsupported rails. Great

Still not entirely sold on the cam idea, it seems...inflexible.

The alu extrusions, have you found any systems that 'mate' nicely? I can't get an easy combo of extrusion/rail supports, etc. Is it always simply a case of having to drill it yourself to accommodate the rails? Ideally, I want to have minimal machining, since a) I can't do it very accurately with what I have, and b) using the extrusions slot features allows some flexibility in future.

I think I will end up making my own driver board, but it's good to see nema17 is sufficient. I suppose 24V is the best voltage for them?