Printable View
looking at replacing the 25 year old steppers in my cnc with hybrid servo/steppers.I know leadshine are generally popular, ive seen these ones on ebay. any model better than others, anything to watch out for?all thoughts welcomethere used to be lots for sale on ebay, but mainly seems to be leadshine drivers at the moment, not many servoshttp://www.ebay.co.uk/itm/CNC-Leadshine-Closed-Loop-Hybrid-Servo-Drive-Kit-HBS57-Driver-Motor-encoder-/251942156746?hash=item3aa8ec39ca:g:EiAAAOxydlFSutQ h
Can I ask Why you want to change.?
I've used this setup and while they work very well the only reason I'd use them over standard stepper is because the motors are 3 phase motors which give much smoother operation and stronger thru out the rpm curve compared to 2 phase steppers. The actual Closed loop isn't that important or needed if normal steppers are sized and tuned correctly.
Normal 2 phase steppers matched to decent digital drives like leadshine DM, EM or AM drives give great performance and reliabilty for the money. You'll get DM556 and 2 or 3nm Motor for around half the cost of the C-loop and if run with around 44v they'll work great. If the gap was closer on price I'd say go C-loop for 3 phase motors but unfortunatly it's not.
Also if looking at the Larger C-loop motors then I'd look towards servos because most are just normal 2 phase steppers which offer no advantage other than the C-loop over normal steppers.
I have a denford triac with original stepper setup, so standard nema34 steppers, controlled via digiplan drivers, connected to a pmdx26 via a home made 5v to 24v board.
so I don't have micro stepping, which I would like. my current max speed is 1200mm/m which is pretty slow.
so I want to increase steps and speed up
two of the stepper motors are 25 years old
Well in that case I'd give C-loop a miss because pretty sure all the 34 motors are 2 phase motors. Those you linked to are Nema 23 and only 2nm.Quote:
Originally Posted by andy_con
If you buy Am882 drives for around £50-60 each and fit motors below and run them around 70Vdc you'll transform the machine. In fact just the drives alone and some more voltage will make big difference.
https://www.cnc4you.co.uk/Stepper-Mo...4808-02-Nema34
thanks for the link
have you ever used the leadshine hybrid servo to compare agains standard steppers?
Yes and like I say the 3 phase motors are noticebly smoother and hold torque higher up the speed curve. But the larger 2 phase motors work just like normal steppers to me but with closed loop feedback to drive. Good digital drives and normal 2 phase steppers give the same performance to me.Quote:
Originally Posted by andy_con
So why are the leadshine so expensive? Are they well made and good quality? Very reliable?
On a nema34 frame size, if money was no object what's the best setup you could buy?
I like to aim high in life and then work down from there ;-)
If your meaning Leadshine closed loop then your paying for the encoder and novelty of closed loop. The AM882 are Leadshine drives and they are not expensive. Quality wise they are very well made and reliable. The software technology is well proven and tested. Most of the cheap chinese drives you see are rippoff's of leadshine technology.Quote:
Originally Posted by andy_con
Me I'd buy AC Servo's if money wasn't concern. Or maybe these, not tried any yet but heard good things about them.Quote:
Originally Posted by andy_con
http://www.teknic.com/products/clear...-servo-motors/
Do you know how to see the Clear Path SD stepper killer models with prices? I registered there but it constantly loops me from publicity to publicity. Some geek made that webQuote:
Originally Posted by JAZZCNC
PS: I found it. It was : "Help me choose a motor.." then down bellow small button "skip and show all models"
I looked around, while they may seem right for Americans, i doubt their value for us. The "stepper killer" seems not a true servo but a closed loop stepper motor, judging from torque at speeds, prices from >300$, then the true servos are from >600$ . For that money one could buy a brand new Brand servo motor +controller.
For ~700$ i could tell you where to buy 4 servos/200w or 400w/ and motors together, though i did not have time to buy and test them. China of course. Seems though people use them re branded and pay greater prices for them.
No they are proper DC servo motor and light years better than stepper system. Plus the question was if money wasn't a concern.Quote:
Originally Posted by Boyan Silyavski
You can't possibly compare them to cheap chinese servos because the quality of these would be like comparing to high end Yaskawa or Mitsubishi. It Would be like comparing Apples with oranges.!!
But coming back into our world in budget terms then please do because at £175 for set of 400w motor/drive and I presume cables then thats good price.Quote:
Originally Posted by Boyan Silyavski
Edit:
Forgot to say you can't buy Clearpath direct from Technik they route you thru distributor which did contact me but I didn't persue it any further.