Losing Z Height in Mid Operation

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garylmast
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Losing Z Height in Mid Operation

Post by garylmast »

I have a fairly new (Chinese Import) CNC router (which is my third) that has not much more than 50-75 hours on it. I have checked to make sure everything is tight, which it is. The X-Y-Z and A axis are within .05 mm tolerance when I checked the calibration. My post processor is set to save @ G Code (mm) (*tap) and all my work is done in millimeters. Up until now I haven't had any problems. I am running Mach 3.

The problem I'm now having is the "Z" height is good but starts to drop after quite a few minutes of running. I can get through on small jobs okay, but start seeing the problem after 30-40 minutes. Any suggestions or help?
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PaulRowntree
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Re: Losing Z Height in Mid Operation

Post by PaulRowntree »

Can you swap the drive for Z with X or Y? If the problem remains, the problem must be afte the driver (wires ? connectors ? motor ? drive mechanics ?0
If it moves, then probably that driver channel is overheating and malfunctioning, or whatever is giving the step pulses is failing...
Cheers!
Paul Rowntree
WarpDriver, StandingWave, Topo and gadgets available at PaulRowntree.weebly.com

garylmast
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Re: Losing Z Height in Mid Operation

Post by garylmast »

Thanks Paul, I'll see if your suggestions help. Gary

garylmast
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It could of been the full moon

Post by garylmast »

After taking Paul's advice, I started checking connections and switched wires from the Z motor to the A motor (rotary device) but saw no difference, so I switched things back, still no difference. I was still losing "Z" height. Thinking there is no surge protector for the 220 volt line that supplies the computer components in the CNC machine, and there was no available inline 220 volt surge protector I could readily locate, I purchase from Home Depot a "whole-house" surge breaker that I installed at the bottom of the electrical panel box that powers my garage. I just surfaced a new sacrifice board and it turned out perfect. Maybe there was some power fluctuation and by way, there was a full moon last night.

We put a surge protector on our computer in the house, I think it's also a good idea to protect the electronics in our shop equipment. Gary
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PaulRowntree
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Re: Losing Z Height in Mid Operation

Post by PaulRowntree »

I am glad that you have found a solution; I wouldn't have thought of that. I didn't even know that such devices exist.

My guess is that while surges may make a problem more evident, you still have something that is marginal on the Z channel that makes it more sensitive to power-line issues.
Paul Rowntree
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rscrawford
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Re: Losing Z Height in Mid Operation

Post by rscrawford »

Another thing for people to check is their ground. Many shops aren't properly grounded (insufficient placement of rods or plates in the ground), and the static electricity build-up can play havoc with stepper or servo motors (especially if you are running dust collection - builds up a lot of static).
Russell Crawford
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darde
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Re: Losing Z Height in Mid Operation

Post by darde »

Our electric company just changed out our transformer yesterday. On the weekend I stopped by our office and the place smelled like burning plastic. The electrician came and checked the voltage coming into the building. It was 160 on 1 line and 90 on the other. We have been having problems since a storm went through in the beginning of August. We lost about $20 000 worth of equipment the first time. We had battery backup on most everything and lost some of those but they saved our computers and information. electricity can do some funny things. I have had the static problem before also so check that out and ground your dust collector.

garylmast
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Re: Losing Z Height in Mid Operation

Post by garylmast »

My problem was solved by replacing the Stepper Motor.

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