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Spindle Drive Repair On A Citizen Swiss

DPM

Aluminum
Joined
Mar 11, 2013
Location
Pomona
I have a 1990 Citizen L10 Swiss CNC and the spindle drive (actually inverter) is acting up. Spindle will be rolling along just swell and then blast off to full speed out of no where and will stay stuck there.
The machine controls are Yaskawa but the spindle control is Mitsubishi - P/N FR-Z220-3.7K
I called Mitsubishi and they won't touch it. Looking for some known repair shops that can handle this.
Hoping to get some references from you all.

Thanks much.
2019-09-16 19.03.28.jpg
 
Theres a shop here that can handle it I am sure. His name is George forget his number got it at office. Wheelking knows who I am talking about. I posted somewhere on a haas thread about it. if I dont find it tonight, shoot me a Email tomorrow and I'll get it for you.

delapril@cox dot net
 
Have you tried calling Yaskawa? They might have a suitable new replacement that can be easily configured. Just a thought. I found them to be pretty helpful when I replaced an obsolete spindle inverter when it died and parts weren't available.
 
I called Yaskawa and this item is obsolete with no support. They did offer a retrofit but it would be cost prohibitive. I'm thinking about trying this company for a repair: Galco
 
I've seen this happen on a wafer developing machine. (a glass wafer is placed on a chuck, and spun up while a developer is sprayed on the wafer)

The encoder was all gunked up, and would randomly go to full speed (and throwing off the chuck whatever was running). Probably not likely to be the problem, but an easy thing to clean.
Matt
 
This ^ is a really good observation/suggestion. The FRZ is a commodity drive. I've worked with a few and do not recall them having any direct speed feedback capability. The spindle encoder feeding back into the CNC is likely the only feedback. If the feedback goes away, the CNC might try to increase the command to the drive resulting in the overspeed situation.
 
I'm still working on this. Been checking cables etc. Tonight I'll pull the encoder apart and see what happens there. Thanks for the suggestion.

Update: I pulled the encoder apart and it was clean. No smell of burnt electronics. Put it back together and still malfunctioning. I can enter M3S0 and the thing will fire up to full speed. Any ideas will be appreciated. Thanks.
 
Vancbiker:

You're right about the price. But there's no guarantee the parameters of the Ebay unit are the same as mine. That's what's keeping me from going down that road.
 
Vancbiker:

You're right about the price. But there's no guarantee the parameters of the Ebay unit are the same as mine. That's what's keeping me from going down that road.

If the original drive does not have the key pad just be sure to buy a replacement drive with the keypad so you can enter the proper values. They just plug into the drive and are easily swapped from drive to drive. The keypads are also available separately on ebay. Even if you send your drive out for repair it is likely to come back needing the parameters reloaded. Hopefully you have a list of them.

As far as checking the encoder, you need an oscilloscope to look at the signals. Just checking to see if it is clean doesn't mean it is working.
 
If the original drive does not have the key pad just be sure to buy a replacement drive with the keypad so you can enter the proper values. They just plug into the drive and are easily swapped from drive to drive. The keypads are also available separately on ebay. Even if you send your drive out for repair it is likely to come back needing the parameters reloaded. Hopefully you have a list of them.

As far as checking the encoder, you need an oscilloscope to look at the signals. Just checking to see if it is clean doesn't mean it is working.

Thanks for the input. Still trying to work it out.
 
Update: It turns out that the spindle inverter is good. The problem is the reference signal coming in to the inverter is stuck at full voltage (5V in this case). The problem is coming from the main motion control unit which is a Yaskawa Motionpack 110. Now I'll have to figure out exactly where because none of the units are showing any alarms.
 
Problem finally solved. After quite some time I went back into the machine and traced the 5V signal wire that was going into the spindle inverter and found that the power supply was the culprit. This is where the 5V DC for the inverter was being generated. One of the DC legs was all over the place. I sent it out for repair. Got it back, put it in the machine today and all working good again. Hope this helps anyone in a similar situation.
 








 
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