Last Call - Chinese AC Servo For Spindle Upgrade

[RJS100]

I am about to pull the trigger on a spindle upgrade for a PM833-TV benchtop mill. Uwe (aka Suntravel on this forum) was kind enough to share wire diagrams and programming notes for a 1.5kw JMC AC servo. As I have limited knowledge of servos, these schematics and notes are a huge plus for me.

In a perfect world, I think a 1.8 KW AC servo would be a better fit for this mill. There are a number of these 1.8kw servos all over Aliexpress, Ebay and Amazon. There are a several different model numbers, and brands, but I think there are only a few actual manufacturers. I believe either Rattm, JMC or Lichuan. I searched the Centroid data base for possible schematics but no real match. Lichuan has a B2 series and there is a Delta schematic in the database with a B2 in the name, but the rest of the alphabet does not match.

Just checking one to see if any body has any schematics or notes for any of these models/brands?

Best... Richard

[suntravel]

Most of these Servos with speed mode (analog input) are working similar.
Since Acorn delivers only 0-10V
You need Inputs on the Servo for Direction and Enable and one Output for ALM as minimum requirement.
Download the servo manual before a purchase, if it fits the requirement it will work.
I would stay away from servos with only a few pages manual half full of Chinese typo or senseless English translation

Uwe

[RJS100]

Yes. I have requested manuals for the two other options and will see if I can make sense of them.

[WesM]

I cannot help you on the schematic, but I did see that Delta sells a B2 2kw servo. Its 3k rpm with 5k max rpm. I was investigating it for if the spindle motor on the machine I'm retrofitting ever dies. Pricey though at around $800. I would expect the documentation to be far superior on the delta though, the Delta B2 and A2 servos are used on several pieces of heavy machinery (medium size bed mill and a couple blanchard grinders) where I work.

Dmm Tech also has a 1.8kw servo that might be worth looking into, they seem to be pretty popular too and have good support from what I hear.

EDIT: found this toato 1.8kw, if you go to the downloads section it has manual and tuning instructions. no idea if they are any good though! several guys on cnczone have purchased from fasttobuy, they have an ebay store as well.

https://www.fasttobuy.com/18kw-220v-hig ... 35894.html

[suntravel]

From reading in the forum, I would never get a DMM Servo, too many problems I never had with decent Chinese servos.

Uwe

[Muzzer]

Here's the Lichuan B2 manual https://m.europages.com/filestore/galle ... 63bf17.pdf. And a link to their servo products http://servo.xlichuan.com/products.aspx ... Id=t3:11:3

I used the Lichuan A4 / A6 servos on one of my machines. Fairly basic, with minimal access to internal parameters. The "software" allows you to download a table of parameters that you can edit and then upload again. Certainly, compared to the likes of Yaskawa etc, these are very simple and limited, with nothing like a wizard or GUI to be seen. However, if you use them as you would a stepper drive, they seem to work OK. The fans were godawful noisy, so I replaced them with quieter PAPST equivalents with the same flowrate. I would expect a similar experience with those other Chinese brands.

I would echo Uwe's caution over the DMM Tech systems. In terms of design and construction, they look closer to the Chinese brands than mainstream industrial products. Although the software was more graphical and user friendly, they are clearly not on a par with the likes of Yaskawa etc.

You have a choice - full fat industrial drives (Yaskawa etc), mid range (DMM Tech etc) or Chinesium (Lichuan etc). The price will reflect what you get. I've used all 3 of those to reasonable effect, although in my case I bought used Yaskawa for a similar price to the new Lichuan.

[suntravel]

Lichuan servos are kind of simple, right. JMC manual is about 140 pages with sufficient software for tunning featuring an oscilloscope also.

Uwe

[WesM]

From reading in the forum, I would never get a DMM Servo, too many problems I never had with decent Chinese servos.

Uwe

Oh, I must have missed those posts. I know some folks had to RMA a few, but did not realize there was a general issue with Dmm-tech. Marty used them in a few of his videos and seemed to like them.

For myself I would go with the delta B2 or B3 if I wanted a property supported servo product. They cost about the same as the DMM servos and have a long history of industrial use. There are 20+ y/o delta servos that have been in use every day where I work with very few issues.

Having said that, I get the appeal of the Chinese servos at 1/3 the cost, I got stepperonline T6 servos (rebadged leadshine EL6) for my project. It will be interesting to compare them to the Delta's we have at work.

[suntravel]

Delta are Taiwanese Products, but more in the higher end range...

Uwe

[WesM]

One thing I noticed, with the chinese servos, most are rated for 220v +/-10%. If your local power company is like mine, they run the local transformers at 240v +/-5%. I have measured my 240v at 247vac quite frequently, which would be outside the operational range of the chinese servo's 220v +/-10%. I'm curious if anyone else running these drives has run into this issue. I guess it means using a buck transformer to bring the voltage down into operational range?