Chinese Servo tuning

[Hood]

Has anyone here got experience of tuning any of the AC Servos from China. I am considering getting some, specifically the Lichuan A4 type as per the pic below. I downloaded their software and eventually managed to get it loaded on an old XP computer (couldn't get to work on W10 even in compatibility) The software however looks to be just an easy means of setting parameters and there doesn't seem to be much in the way of tuning compatibility built in, in other words it is just a computerised method of enter parameters rather than using the drives buttons.

I am a bit wary of buying the drives/motors in case they are a nightmare to tune.

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[Tenson]

I'm thinking about servos too. I saw This Old Tony's video where he uses Leadshine servos and it makes it clear to me the tuning software is just as important an aspect as the hardware. https://www.youtube.com/watch?v=tiVWBOBUlaA&t=1485s

However those leadshine ones are still kind of pricy if you can even find the current models on a Chinese market place. I costed them up as about £200 for the driver (www.shop.cncdrive.com/index.php?categoryID=168) and £300 for the motor (Polish website I can't even find again).

However I've heard many also recommend Delta servos and they seem to be priced somewhere between Leadshine and Lichuan and their software website also mentions some advanced software tuning such as automatic resonance detection and notch filtering.

https://www.deltaww.com/en-US/products/Servo-Systems-AC-Servo-Motors-and-Drives/225

[Hood]

Someone else on another site mentioned the Deltas and said they were excellent so it may be the way I go. They are only fractionally more than the Lichaun ones from what I have seen.

[BigBrand]

I too have been looking at these servos and also worried that the backup needed for installing them correctly might be lacking. I've hunted all over for any software and through the manual but found nothing yet.. surely they cant not provide this? Or is there possibly some sort of inbuilt auto tuning?

Its a bit worrying you cant find anything in the software.

They also can't provide a torque graph for the motors only the rated numbers. So im finding it hard to know what torque is available at what speeds which is making my decisions even more difficult.

[BigBrand]

When researching the deltas ive come across videos like this which is somewhat reassuring... https://www.youtube.com/watch?v=adc5untQcYI

[pippin88]

I too have been looking at these servos and also worried that the backup needed for installing them correctly might be lacking. I've hunted all over for any software and through the manual but found nothing yet.. surely they cant not provide this? Or is there possibly some sort of inbuilt auto tuning?

Its a bit worrying you cant find anything in the software.

They also can't provide a torque graph for the motors only the rated numbers. So im finding it hard to know what torque is available at what speeds which is making my decisions even more difficult.Are you referring to the genetic Chinese servos sold under many brands?

They are often sold by drop shippers that have no idea about anything they sell.

I've got a Delta 750W B3 servo as a small lathe spindle motor. The Delta manual is good and written in proper English. Software is easy to use. B3 series plug into PC with miniUSB (older models need a special programming cable).



When buying from China, I usually stick to stores that sell a limited range of products. I've had very good experiences doing this. If they sell everything under the sun they will know nothing.

[Hood]

I too have been looking at these servos and also worried that the backup needed for installing them correctly might be lacking. I've hunted all over for any software and through the manual but found nothing yet.. surely they cant not provide this? Or is there possibly some sort of inbuilt auto tuning?

Its a bit worrying you cant find anything in the software.

They also can't provide a torque graph for the motors only the rated numbers. So im finding it hard to know what torque is available at what speeds which is making my decisions even more difficult.

Aye, info is non existent on those Lichaun servos and the software is Chinese only as far as I can make out. I don't think there is any automatic tuning in them or at least I don't see any mention of it and if there was such a thing you would think it would be getting shouted about.

Regarding the torque curves, most AC servos will have a relatively flat torque curve so you can more or less assume that it will be around about the continuous torque for the range of the rated speed. Then again as the saying goes, assume can make an ass of u and me. :D

[Hood]

Are you referring to the genetic Chinese servos sold under many brands?

They are often sold by drop shippers that have no idea about anything they sell.

I've got a Delta 750W B3 servo as a small lathe spindle motor. The Delta manual is good and written in proper English. Software is easy to use. B3 series plug into PC with miniUSB (older models need a special programming cable).



When buying from China, I usually stick to stores that sell a limited range of products. I've had very good experiences doing this. If they sell everything under the sun they will know nothing.

The ones I was meaning were the ones made/sold by Lichaun which seems to be a very big company.

The Deltas seem to be much better in that they have better documentation and supposedly very good tuning software and they are likely what I will now go for if I do indeed need to go down the new servo route for the plasma.

[BigBrand]

i've been on with them and this is this what they sent me when i specifically asked about tuning. Is this what you found? It doesnt look too promising?

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[Hood]

That is a bit better than I found because what I saw was all in Chinese 😁

[BigBrand]

All the install procedure was.. i was thinking what on earth am i installing here.

Can anybody who knows what they are talking about (not me) confirm if this is whats necessary to successfully tune the motors?

It certainly doesnt look as user friendly as the delta stuff.

[Hood]

It is certainly not user friendly and likely could be used for tuning but without instructions on how to use I think it could be quite frustrating.

[BigBrand]

think im going to swerve these

[Hood]

Likewise, I think the Deltas are the way to go for me if the need arises. They are a bit more expensive but not a huge amount and the documentation and software more than makes up the cost difference in my opinion. Add to that I have heard good things from several people about them then it seems the wise choice.

[Muzzer]

I have the Lichuan "software" installed on 2 of my machines, both Windows 10. One won't work at all when I try to run it and the other gives errors but still "works". But as you say, the "software" simply allows you to type in the parameter values in a sort of spreadsheet format which can be read and written. It's rather underwhelming but the motor + drive cost was dirt cheap, not least as I got a promotional offer. The features available within the Lichuan are minimal but at least they actually seem to work as servos. Be aware that the fan is always enabled with these and they are noisy.

I also have Yaskawa and DMM Tech servos, both of which have recognisable software for tuning the transient response in a meaningful way. The DMM Techs are pretty reasonable but my early DYN2s are set up more like stepper drives than pukka servos. They are somewhere between hobby and industrial in build quality and features.

The Yaskawas are pretty much the gold standard for industrial servos. The software is almost overwhelming in terms of what it offers and the features in the Sigma drives are also very comprehensive. But at least you have config wizards and tuning tools. One of the key challenges is the Japanese equivalent of Chinglish ie understanding WTF they meant when they wrote the words I'm sure they knew themselves.

The Deltas look close to the Yaskawas, which perhaps isn't a surprise, as they are proper industrial drives too. If you can grapple with the documentation, a Delta or a used Yaskawa might be the sweet spot for me. Depends what you want to do and how much dosh you want to spend....

[Hood]

I have used quite a few different servo drives over the years from Osai (rebadged Electrocraft BRU) to Allen Bradley DDM, Allen Bradley DSD (which I still have on the plasma, lathe and one mill) , Telemecanique (Schneider/Berger Lahr) Lexium drives (on my Chiron) and even Samsung CSDJ drives. All had some form of software for tuning even the ancient Osai drives (still have a few :D ) it was in Windows HyperTerminal that you tuned it with, it had a rudimentary auto tuning and also a manual tuning and I am sure it had outputs you could connect a scope to.

Alll of the other drives, as said, had software for configuring I/O , tuning etc and all had auto tuning and manual tuning capability. The Allen Bradleys worked reasonably well with auto tuning but could be further tweaked manually if you wished better, the software was very user friendly. Likewise the Telemecanique Lexiums although I would say their auto tuning was a bit better but the software was definitely not as user friendly as the AB ones. The wee Samsung though was excellent, software was decent, not as good as AB but better than Telemecanique but the tuning was basically automatic and worked exceptionally well with no need for any manual tuning on the wee lathe I had it on.

[Muzzer]

The "autotuning" on the DMM Tech DYN2s was laughably useless. But at least you could set a variety of demand waveforms through the GUI and observe the response graphically while fiddling with the settings.

[BigBrand]

Interesting.. so whats involved with your lichuan drives then? Or do you not need to and they just 'work'?

[Muzzer]

At the moment I'm cutting air on the bench, so in that respect "they just work". But when I have them installed for real, I will need to tune them. At which point the true horror of the "tuning" process will become apparent.

I suppose one option may be to use the LinuxCNC controls to do that without changing the Lichuans. For now, that isn't at the front of the list.

I've just made my own HTD3 pulley due to the crap backlash in the Chinesium pulleystock used in the pulleys I got from Bearingboys. Wasn't planning on doing that but it seemed the only concrete solution, short of buying loads of random pulleys from various suppliers and hoping some were ok. Also gave me the opportunity to break out the 4th axis again. This uses a Yaskawa Sigma servo and motor.

With an iPhone and Windows 10, this forum doesn't know which orientation to use on the photos, although they look OK in W10. Every forum seems to be different! What is the way to fix it here?

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[3Dogs]

At the moment I'm cutting air on the bench, so in that respect "they just work". But when I have them installed for real, I will need to tune them. At which point the true horror of the "tuning" process will become apparent.

I suppose one option may be to use the LinuxCNC controls to do that without changing the Lichuans. For now, that isn't at the front of the list.

I've just made my own HTD3 pulley due to the crap backlash in the Chinesium pulleystock used in the pulleys I got from Bearingboys. Wasn't planning on doing that but it seemed the only concrete solution, short of buying loads of random pulleys from various suppliers and hoping some were ok. Also gave me the opportunity to break out the 4th axis again. This uses a Yaskawa Sigma servo and motor.

With an iPhone and Windows 10, this forum doesn't know which orientation to use on the photos, although they look OK in W10. Every forum seems to be different! What is the way to fix it here?

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@Muzzer -
Did you ever get the Lichuan A4 and servos running and tuned?
I am thinking of buying these, but the lack of support for the tuning process is worrying.

[Muzzer]

I've been using them on both my lathes and they have been fine. There's no real option to tune the drives themselves but you can tune the higher level system. I have closed loop position control on one of them (the Bantam, using Linuxcnc and glass scales) and the response is pretty impressive. Main thing is to make sure the torque and power are adequate for your machine. Best to err on the safe size, not least as they are fairly low cost. The other thing I did was change the fans, which sounded like a nest of angry wasps.


https://www.youtube.com/watch?v=oRGrclMb6_E