Chinese 'Hybrid Closed Loop' steppers vs 'regular' open loop steppers

Newbie here, looking at hardware choices for the X and Z for my Boxford 240TCL update.

Browsing the variety of Chinese stepper motors on eBay. I've noticed that the prices on what they call 'hybrid closed loop stepper motors' - i.e. a package of stepper motor with encoder and control box - is now around the same price per unit as what I would pay for similar open loop models without the encoder which are not trying to ape a servo system. Equivalent NEMA 34 size units are around 30mm longer, accounting for the encoder.

Does anyone out there have any experience of fitting and using these (usually 2 phase) in preference to open loop equivalents? Bearing in mind the equivalent price, is this a worthwhile choice?

Many thanks in advance.

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Originally Posted by clutchslip

Newbie here, looking at hardware choices for the X and Z for my Boxford 240TCL update.

Browsing the variety of Chinese stepper motors on eBay. I've noticed that the prices on what they call 'hybrid closed loop stepper motors' - i.e. a package of stepper motor with encoder and control box - is now around the same price per unit as what I would pay for similar open loop models without the encoder which are not trying to ape a servo system. Equivalent NEMA 34 size units are around 30mm longer, accounting for the encoder.

Does anyone out there have any experience of fitting and using these (usually 2 phase) in preference to open loop equivalents? Bearing in mind the equivalent price, is this a worthwhile choice?

Many thanks in advance.

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I’ve been using a Norma 34 close loop stepper on the Z axis on my boxford bud cnc conversion lathe. It’s been up and running 2 years and works perfectly. Very accurate and I have never noticed it loosing any steps
The nema34 is direct drive through a 5mm pitch lead screw
Would it have performed the same without the close loop, I’ve no idea

Paul


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I've got Lichuan NEMA24 closed loop steppers on all axes on my machine and can't fault them, never had any accuracy issues even when pushing fairly hard.

I used a Leadshine closed loop stepper on the Z axis of my Bridgeport conversion. It's the "Integrated Easy Servo" version, where the driver is built in to the motor, so you just feed it volts (36V?), step and dir, then it does the rest. Pretty tasty - and being Leadshine it just works.
Being a stepper, it makes an audible noise but nothing like some of the cruder stepper drives. You can tune it with their software if you think you have what it takes and there is a configurable output that tells you if it's out of position etc. Why go closed loop if you don't then check it's in control etc.

http://www.leadshine.com/producttype...y-servo-motors

There are quite a few clones around now (Aliexpress, ebay etc) but I've no idea how good those are. Note they only do 2-3Nm max.

Like this: https://uk.banggood.com/JSS57P2N-Nem...r_warehouse=CN

For some unknown reason, AliExpress are doing a 15% "11.11 discount" today, so I've risked the wrath of the Domestic Manager by placing an order for a couple of 600W servo motor / drives from Lichuan. 11 isn't even a Chinese lucky number as far as I know but perhaps that's where I went wrong during the many years I spent visiting the damned place. https://www.aliexpress.com/item/1005...191c4c4dmmZxSS For this, I blame a combination of beer, a late life crisis - and of course JAZZCNC, for recommending the buggers. No idea how well these will work out but I'll let you know.

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Originally Posted by Muzzer

For this, I blame a combination of beer, a late life crisis - and of course JAZZCNC, for recommending the buggers. No idea how well these will work out but I'll let you know.

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It's ok I've got broad shoulders and I know you won't be dissapointed provided your not expecting them to match Mitsubishi's or Yaskawa's. I've got some on my Plasma machine.

To the OP then I've been using Closed loop in both Nema 23 and 34's for several years now, I stopped fitting standard steppers over 3 years ago as they just don't compare to closed loop. I wouldn't fit standard steppers these days as the price difference just isn't worth it.

Now to anyone on the forum who's looking to buy I've got a large shipment of Lichuan 4.5 and 5.5Nm 2 phase nema 24's with 70Vac/100Vdc drives arriving later this month which I'm willing to sell a few sets to forum members, also some large mains powered Nema 34's but only got a few sets of those coming.

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Originally Posted by depronman

I’ve been using a Norma 34 close loop stepper on the Z axis on my boxford bud cnc conversion lathe. It’s been up and running 2 years and works perfectly. Very accurate and I have never noticed it loosing any steps
The nema34 is direct drive through a 5mm pitch lead screw
Would it have performed the same without the close loop, I’ve no idea

Paul


Sent from my iPhone using Tapatalk

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Thanks for the reply Paul, good to know yours have been reliable. My setup is not a direct drive like you have on your Boxford, but can I ask what motor torque capacity you went for your Z axis? What vintage is your BUD by the way?

The cost of these Lichaun servos is about what you'd have paid a Korean scrappie for a set of used Yaskawa Sigma 5 or 6 from 15 years ago. Speaking from experience. And of course they are essentially Yaskawa / Panasonic clones.

I thought I'd go for the new Lichaun option this time. I'm not exactly an OEM developing a volume product, so what have I got to lose? Well, my bollocks, hanging from the washing line 2 weeks from now, now that I think about it.

To be honest I can remember
I know it was a Nema 34 and I bought the biggest I could afford as I couldn’t find any guides to what I needed hence I thought bigger is best. For the same reason I went close loop
From memory about £130 for the motor and stepper driver
Boxford is 1974 on its original cabinet stand with 3phase drive motor now running via a 2.2kw vfd all under cnc control
Running on mach3 on pokeys

Paul


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Thanks for the other replies so far. Thankyou to Muzzer for the headsup on Lichuan on AliExp. JAZZCNC thanks for the above - I've found a couple of very useful comments of yours on similar threads regarding importance of power supply voltage etc. Plenty more reading and research to do on my part before I start spending any money....Muzzer your comment about the 'Domestic Manager' reminded me of an older guy I used to work with who used to recount every detail of his exploits to keep his spending beyond the control of 'the Chancellor' back at home.....

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Originally Posted by Muzzer

The cost of these Lichaun servos is about what you'd have paid a Korean scrappie for a set of used Yaskawa Sigma 5 or 6 from 15 years ago. Speaking from experience. And of course they are essentially Yaskawa / Panasonic clones.

I thought I'd go for the new Lichaun option this time. I'm not exactly an OEM developing a volume product, so what have I got to lose? Well, my bollocks, hanging from the washing line 2 weeks from now, now that I think about it.

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Bloody hell just noticed you are also in st Anne’s. Small world

Paul


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