Superior Electric Steppers

[JAZZCNC]

If I go for conventional steppers I'll go with the AM822 drivers, but what size motor? The old steppers have a surprisingly small shaft (3/8") so Nema34s with 14mm shaft are a bit of nuisance. I see Nema23 3Nm motors with 10mm shafts - http://r.ebay.com/KuT9Ez - Are these big enough though?

Ok well first need to check if the machine is fitted with Ballscrews not just lead screws which you are calling Ballscrews.?

If ballscrews then 3 or 4Nm Nema 23 motors will probably work. I've fitted loads of Both 3 & 4nm motors and to be honest see very little difference between them in performance terms so wouldn't stress over which to use. The Key is buying ones with Low inductance. No higher than 4mh ideally closer to 3mh.
These are better motor and will fit your needs.
https://www.cnc4you.co.uk/Stepper-Mo...H401-03-Nema23

If you speak to them Don't Let them Bullshit you into believeing there drives are as good or better than Leadshine AM or EM they are not.!

[JAZZCNC]

This maybe your Lucky day my friend.?

Just remembered somewhere in box I've got some motors and sure enough there was.!! And guess what they are 2 x Brand New 34's with 10mm shaft 8 wire motors model number FL86STH65-2808A-H. Think about 3.5Nm but would need to dig out motor data sheet.

Also got another 34 4 wire motor with 12mm shaft which is around 4Nm I think. SY85STH65-5904B.

Drop me PM if your interested.

[Agathon]

This maybe your Lucky day my friend.?

Just remembered somewhere in box I've got some motors and sure enough there was.!! And guess what they are 2 x Brand New 34's with 10mm shaft 8 wire motors model number FL86STH65-2808A-H. Think about 3.5Nm but would need to dig out motor data sheet.

Also got another 34 4 wire motor with 12mm shaft which is around 4Nm I think. SY85STH65-5904B.

Drop me PM if your interested.

Great, I'll pm you.

[Agathon]

Ok well first need to check if the machine is fitted with Ballscrews not just lead screws which you are calling Ballscrews.?

If ballscrews then 3 or 4Nm Nema 23 motors will probably work. I've fitted loads of Both 3 & 4nm motors and to be honest see very little difference between them in performance terms so wouldn't stress over which to use. The Key is buying ones with Low inductance. No higher than 4mh ideally closer to 3mh.
These are better motor and will fit your needs.
https://www.cnc4you.co.uk/Stepper-Mo...H401-03-Nema23

If you speak to them Don't Let them Bullshit you into believeing there drives are as good or better than Leadshine AM or EM they are not.!

Yes, definitely ball-screws. This is a very high-class bit of kit and would have cost many tens of thousands when new in 1980. The slides are conventional dovetails but have low friction inserts and are automatically pressure lubricated.

Thanks for the link and recommendation - will look into it.

Sorry to keep harping on about closed loop, but what do you think about using the Leadshine Nema23 kits?

[JAZZCNC]

Sorry to keep harping on about closed loop, but what do you think about using the Leadshine Nema23 kits?

The 2Nm won't be enough IMO.

This machine sounds too nice to be skimping on motor so don't spoil it just for sake of feature that won't give anything more than well setup Stepper would.

For me it would boil down to 2 options. Conventional steppers with Good drives like AM/EM or Servos. Wouldn't waste money on Closed loop Steppers.

[Agathon]

The 2Nm won't be enough IMO.

This machine sounds too nice to be skimping on motor so don't spoil it just for sake of feature that won't give anything more than well setup Stepper would.

For me it would boil down to 2 options. Conventional steppers with Good drives like AM/EM or Servos. Wouldn't waste money on Closed loop Steppers.

I certainly don't want to "spoil the ship for a ha'p'orth of tar". Ironically, that's why I was thinking of closed loop. My initial thoughts were to fit Leadshine Nema34 4Nm hybrid servos, but they are only available from China - or at twice the price from the UK. Of course, I'd love to spend hundreds on quality servos, but as a first foray into CNC I need to keep the costs down.