Superior Electric Steppers

[JAZZCNC]

Just realised that it was your Youtube video of a Leadshine closed loop stepper that turned me on to the idea.

Maybe, as you've said in other threads, I'd be better off with conventional Nema34 steppers and digital drivers. Just like the idea of the smooth closed loop, but there's no point if the two phase motors aren't any smoother.

Thanks again for your help.

Yes that's me.!!

Standard 34's with Am882 will be perfect for Mill. When correctly setup there will be no difference between 2 phase Closed loop in performance terms.
If the machines loses position the closed loop will bring it back into line yes.!! . . But the damage will still have been done if it was machining at time. Again Correctly sized and setup stepper shouldn't lose position so it's not problem. I've built loads of routers using the AM882 and Em806 drives along with 34 and 23 steppers which travel high feeds where torque is lower and they don't lose position so on slower moving mill you won't have any trouble.

[Agathon]

It's a shame that the Leadshine Am882 doesn't appear to be available in the UK. Is there another driver worth considering?

Just a final thought on the closed loop steppers. Given the details of the original motors, do you think the Leadshine 3ph Nema23 2Nm motors would provide enough torque?

[JAZZCNC]

Just a final thought on the closed loop steppers. Given the details of the original motors, do you think the Leadshine 3ph Nema23 2Nm motors would provide enough torque?

Difficult to answer without seeing machine etc but the fact the old where 34's and probably wired in series which gives more torque lower down Rpm then it will be close call and one I wouldn't take personaly.

AM882 and 34's would be safer bet.

[Agathon]

Ouch, those EM806 drivers are pricey - by the time I've bought a motor, I've exceeded the price of the Nema34 closed-loop units from Rattm motor in Germany (http://r.ebay.com/jCcjOw).

I notice these drivers claim to be digital - http://r.ebay.com/chJSF8

[JAZZCNC]

Ouch, those EM806 drivers are pricey - by the time I've bought a motor, I've exceeded the price of the Nema34 closed-loop units from Rattm motor in Germany (http://r.ebay.com/jCcjOw).

Don't be fooled by the Germany part. They will come from China. You'll get message saying don't have stock in Germany and will be 6-8wks before re-stock and would you like them sent from china.

Don't be put off buying from china if you can afford to wait. You'll get AM882 cheap enough. I've used lots both EM and AM there's very little between them in performance terms.

[Agathon]

Very good advice as usual. Many thanks.

[Agathon]

Just to throw something else into the mix... I contacted Fehlmann (the makers of my mill) and asked them what they used on the modern equivalent of my machine. They now use Omron "Smartstep" servo motors (R88M-G40030h) with a nominal torque of 1.3Nm and a momentary torque of 3.6Nm. 2.6A mains (200v ac) powered driver.

I'm wondering again whether those Leadshine 3ph Nema23 2Nm closed loop steppers wouldn't do the job or is the torque characteristic for a servo very much different to a stepper?

[m_c]

It's a shame that the Leadshine Am882 doesn't appear to be available in the UK. Is there another driver worth considering?

Just a final thought on the closed loop steppers. Given the details of the original motors, do you think the Leadshine 3ph Nema23 2Nm motors would provide enough torque?

The AM series has been replaced by the EM series. The new AM882 equivalent is an EM806.
The original HS closed loop stepper system has also been replaced with the Easy Servo range.