High resolution closed-loop steppers

[Voicecoil]

I came across these today, has anyone had any experience of them I wonder???:

https://www.fastech.co.kr/new/eng/sub0203.php

[JAZZCNC]

They are just a closed-loop stepper system with a higher resolution encoder that provides 32,000 pulses per rev which to be honest isn't really practical unless the drive allows electronic gearing because most controllers won't have the frequency or pulse width to drive it to its full potential. Just to get it to spin at 1500rpm you would need a frequency of 800Khz and most of the lower end controllers like UC300 are 100khz or at best 400Khz ie UC400.

[Voicecoil]

That's interesting 'coz on page 6 of the manual it says encoder resolution of 4,000, 10,000, 16,000 etc. ppr ....I was wondering how they achieved that... I don't think I'd ever want to push it as far as 32,000, just 4,000 or 10,000 would potentially provide a useful increase of resolution over the standard 1,000ppr.

[Muzzer]

Seems utterly pointless. And even though they appear to be using fancy vector control (as do Leadshine), it's still a stepper, so the additional steps will have little discernible effect if you have any sort of load torque applied.

To be fair, Leadshine also offer resolution of up to 51200 steps per rev - from a 1000PPR encoder. To achieve the additional resolution, they must be using some form of open loop interpolation. I can't imagine anyone uses these settings unless they are hoping to be a lunchtime legend / YT willy waver.

[JAZZCNC]

To be fair, Leadshine also offer resolution of up to 51200 steps per rev - from a 1000PPR encoder. To achieve the additional resolution, they must be using some form of open loop interpolation. I can't imagine anyone uses these settings unless they are hoping to be a lunchtime legend / YT willy waver.

I've run them at silly resolutions on 4Mhz controller just for laughs n giggles when testing and to be honest, was surprised just how well they ran, Didn't lose too much torque if any and was very smooth. That said I wouldn't run at those resolutions because the high pitch noise is horrible..:cower:

[Muzzer]

Wow, surprised the optos on the inputs are fast enough to pass those frequencies. The datasheet specifies 200kHz max ie max pulse width of 2us or so. 4MHz infers pulse widths of 100ns or so.
EDIT - actually 500kHz. I need to go to Barnard Castle.