Closed or normal Steppers?

Evening all,

I see that there are now both open loop and closed loop stepper motor drivers are easily available.

Obviously there is a price difference. Is there a good reason to choose the closed loop ones?

Im not sure what size motors I need, but based on what Seig have put in the KX1 and KX3 I’m going to go for about 3NM in a Nema23 frame. My build is not as large travels, but quite chunky bits of steel. That puts something like £100 - £150 difference for closed vs open loop, based on poking around eBay and Amazon for pricing.

I have 1204 ball screws, and hiwin carriages, saddle is 400mm x200mm channel steel, table 200x200 x20 steel, all day on a cast iron surface plate as the base.

Dave

If you size the steppers to suit the load and have a reliable stepper driver set up correctly you shouldn't experience any stepper stalling problems and hence lost steps.

If you intend to use the rig for professional use then perhaps you need to go with closed loop steppers or even servos.

Emgee

Go closed loop. I did on my Denford Starturn lathe and the difference is like night & day.

They're quieter, with almost no resonance bands and will throw an error signal if they can not maintain correct position.

Martin.

Go closed loop, you'll only decide to switch at s later date and spend more in the long run. Try stepperonline, they sell on ebay as well as direct.

Dave s -

Not sure what the total pricing is that you are looking at, but these motors may be of interest -

Teknic Clearpath SDSK series

Closed loop, step and direction driven, dead quiet, no resonances at all...

I used steppers on my one of my Emco FB2 mill conversion and was not happy in th eend, and converted to the Clearpath motors - drop in replacement on size, mounting, control signals, etc. What a difference!

I have also used them on my Shop built CNC lathe , posted on this forum as well as for driving the leadscrew on my DIY ELS fitted to both my manual lathes! Very happy with these motors - fit and forget, never loose steps, even with rather insane accelerations and velocities.

There is a neat comparison video - stepper V Clearpath - lower down on the same page in the above URL

Joe

Edited By Joseph Noci 1 on 04/02/2022 06:17:46

I use closed loop steppers as well. Run cooler, give error signal that can stop everything if they can't maintain position. The potential payback over time in terms of not having to start again when steps are lost is quite high so invest now and save later.

Martin C