Mini Mill Conversion - best stepper drive choice

[murrayg]

Hi Neale,

I work for Charter Controls who are the UK importers for Geckodrive in the USA. I don't know if you have seen any of my previous posts but as a member of this forum you can use a discount code on our website. If you enter coupon code "mycncuk" at checkout you will get 15% off the list price. You can see the items and what we have in stock here: https://charter-controls.com/manufacturer/geckodrive

If there is anything else I can help with, please let me know.

Regards
Murray Greenhill

[JAZZCNC]

Some of this depends on motor type 4 or 8 wire. With 4 wire your stuck to how motors are wound at factory, often series. 8 wire can choose which.

My choice for small Mill would be to go with AM882 with 60-65vdc and wire motors in series. This will give you more torque down low and seen as you won't be going fast there'll still be plenty of torque left up high. The reason you need 60-65V is because series requires more voltage to get decent speed.

Router then you'd wire motors parallel because want more RPM and torque to run higher up the rpm range. This does come at the cost of losing little lower down.! . . . Can't have cake and eat it I'm afraid.

The AM882 will offer more motor choices and upgrade potential if required. There advanced Resonance handling and smoothness are worth paying that little more for IMO.

[GND]

That's a really interesting take there, Jazz. All the motors we are using are eight wire, so we do have complete flexibility. And that means the PSU for the mill only needs to supply half the current that an equivalent router one might - say 4A at your 65v, allowing for a small saving in cost, but a larger saving in space. I am coming round to the benefits of the AM882 even for this application - future proofing certainly - as well as gaining the advanced resonance handling etc. I think that must be the way forwards.

So now I have to take a deep breath and start considering my first large value order into China - six drives. Seems no alternative for the AM882. Anyone have any idea why it's not available in the UK, especially since it is the stepper drive of choice on this forum?

[JAZZCNC]

Just note that if motors are 2A then you'll need to configure current using the AM882 Tuning software as the DIP switch lowest setting is 2.8A. The Tuning software allows setting from 0.5A upto 8A in 0.1 increments.
This will mean you'll require RS232 cable (serial)

Think the reason why not in UK anymore is can't compete with China prices. Don't worry about buying from china I've bough 100s never had issue. But be aware you'll pay VAT and Shipping admin fee around £10-15. If you ask seller they will put low price on paper work which will help with vat.

[GND]

Cheers Jazz - good tip on the current setting, as it will be in the order of 2A for series connected I think.

Good info also on the Chinese supply. Are there any "well proven" Chinese suppliers you could name? Or do you go different each time?