Belts or Balls getting me Screwed up! Help I need advice Please.

[Ger21]

That's not a 425oz motor, it's 439. The OP said 425, so I don't think he's referring to that motor. All the 425oz motors I've ever seen are high inductance.

[Jonathan]

That's not a 425oz motor, it's 439. The OP said 425, so I don't think he's referring to that motor. All the 425oz motors I've ever seen are high inductance.

The motor I linked to and the following one are probably the most popular ones on this forum:

SY60STH88-3008BF

That's 3Nm, so 424.8oz-in and 3.2mH... close enough for you?

I've measured the inducance of both motors and it does match the rating, within a reasonable tolerance.

[longy]

First you'll get a stronger machine if you build it long and narrow rather than wide and short. It would also be easier to join ballscrews with a timing belt and use one motor and have the advantage of keeping screws in sync. Don't bother with timing belts only as they cost nearly as much as ballscrews by time you have bought belt and pulleys etc.
Also the ballscrews want to be 10mm pitch not 5mm if you planning on mainly cutting wood, if you need higher resolution then just put a ratio on the screws.

Thanks for your input Jazz, I had looked at doing it the way you suggested and may well go back to longer / narrower machine. Ball screw pitch I'm not sure what you mean by "ratio on the screws" I do need to have the higher resolution as the laminate I want to cut needs a high tolerance. It's harder than a lot of allies to cut / drill, so do you think I would be better using the 1605 bs ? I'm going take what you've said about the machines orientation and work on another plan, I do know I can rename the axis x & y to fit my machine.

The motor I linked to and the following one are probably the most popular ones on this forum:

SY60STH88-3008BF

That's 3Nm, so 424.8oz-in and 3.2mH... close enough for you?

I've measured the inducance of both motors and it does match the rating, within a reasonable tolerance.

Thanks Jonathan for the links to the motors. I've read your build logs with great interest well done. These are the motors / drive kit that I have been looking at �Germany Ship】4Axis Nema23 stepper motor 425oz-in Dual & Driver CNC control kit | eBay and within my budget, your views are welcome on the kit. I'm keeping well away from those 268 drivers offered with some kits.

Thanks to all for your valued input.

Mike

[Ger21]

These are the motors / drive kit that I have been looking at �Germany Ship】4Axis Nema23 stepper motor 425oz-in Dual & Driver CNC control kit | eBay and within my budget, your views are welcome on the kit. I'm keeping well away from those 268 drivers offered with some kits.

Yes, those are the high inductance motors I'm talking about. They'd need close to 100V to get the best performance out of them, but they give you a 36V supply.

But listen to what Jonathan said. You shouldn't just arbitrarily choose motors and drives. They need to match your choice of screws, and the machine to get the best performance from them. In some situations, motors half the size will easily outperform larger, high inductance motors.

[Ger21]

Virtually all of the 425oz motors available in the US and through Ebay (from China) are high inductance. The ones you linked to are not commonly available over here. So just make sure you know what you're getting.

[longy]

Virtually all of the 425oz motors available in the US and through Ebay (from China) are high inductance. The ones you linked to are not commonly available over here. So just make sure you know what you're getting.

Thanks Gerry, I've not ordered any motors yet, but I will hopefully make sure I get the rights ones.
Mike