[Ron Thompson]

Has anyone used a complete AC servo drive kit to replace existing drives in a commercial CNC machine? I have a 1987 Mazak QT8 lathe, and the cost of repairing 30 year old electronics is disheartening!
I seem to be having one repair issue after another. I recently replaced the old CRT with a Dell LCD thanks to an adapter box, and now the X axis servo is faulting with maybe a resolver or drive issue.
I am just exploring options, here, but the AC servo drive kits include the motor, driver, encoder and cables for an attractive price.
According to info found online, the X axis servo is rated at .5KW. The interesting thing about the kits is you can get a lot more power for just a few dollars more in the same brand.
For example, I am looking at a Delta .75KW kit for about $525US delivered. And there is a TOAUTO 1.8KW AC Servo Motor Drive kit for $387US delivered.
Another advantage to these kits is they operate from single phase 220 VAC. This would lessen the load on my rotary phase converter.
I think that if, down the road, the controller takes a dump, Converting to Linuxcnc would be easier with the drive kits.
Thanks for your time!

[chemphd]

Just make sure that the drive is compatible with your current controller. Yes, good prices can be had on Chinese products, but buyer beware. Read the fine print about the shipping time and costs. Doesn't hurt to ask them for a pdf copy of the manual first to read up on the drive and motor and see how good (or how poor) the English translation is. It really helps to completely understand your current system. Ask yourself, what position feedback does the controller have/expect? Does that come directly from the motor or from the drive? Etc. P.S. Don't expect that Chinese "Delta" drive and motor to be THE Delta--it's undoubtedly a Chinese clone.

[Ron Thompson]

chemphd

Just make sure that the drive is compatible with your current controller.
******************
Good advice. I looked in the wiring diagrams for the Mazak, and there are 6 input lines to the TRS-50B servo drive. They are labeled RS1, RS2, RC1, RC2, and RO1, and RO2.
I am familiar with pulse and direction, but this is Greek to me.

[cajbr]

Try the Linuxcnc dot org forum. A lot of folks are converting older machines and are knowledgeable about the drive interfaces.

cajbr

[chemphd]

chemphd

I looked in the wiring diagrams for the Mazak, and there are 6 input lines to the TRS-50B servo drive. They are labeled RS1, RS2, RC1, RC2, and RO1, and RO2.
I am familiar with pulse and direction, but this is Greek to me.

Those are the resolver signals.

[Ron Thompson]

Thanks for the help. My diagram shows the resolver on the right. I am talking about the left side, going from the NC to the servo amp. (The NC is the control, right?) Maybe it's a feed through for the resolver to get back to the control. In that case, I need the control signals between the control and the servo amp.
It turns out I have an AC servo and drive I got in some stuff a while back. It's a Baldor .57 KW, so it should be a good swap for the Mitsubishi .5KW presently on the machine. I need to test it, but if it's good I won't have to spend money on an experiment.
I also noticed there is a thermal cutout on the motor that feeds back to the servo amp. I need to check to make sure that is not the problem before I do something drastic.
Thanks again for everyone's time reading this!
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