How to determine where a machine axis load, bind, or stick slip problem may be coming from? |
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Axis load checks |
How to check |
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| Move axis back and forth and check for way lube on | Check for oil on the leading edge of the wiper when reversing directions. If way wipers are bad you may not see a line. Instead, wipe the way with your finger and see if there is oil on it. Also, you can just let the machine sit idle for a half an hour or so, then move the axis. You should see much oil in area. If lube pump has a manual override button push and hold for 10 seconds then repeat several times to see if lube comes out. Move axis up and down and repeat backlash test to see if results change. | |
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Does the axis have a brake on it. Usually to hold against gravity? |
If yes, you can usually see the problem with the load meter. Another quick check is to look at the break. Is there a lot of dust or grinding metal? If you can move the axis some. Try moving back and forth a few times and put your hand on the brake. If it is warm or hot that's your problem. See machine brakes troubleshooting |
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| Check the "following error" diagnostic or load meter. | Is it steady or bouncing after a move? Also, try moving handwheel in X1 and see if it takes some time to steady. If it does there is a problem. Compare the following error or load meter to the other axes (should not exceed 1-2 % on the load meter) | |
| Put indicator on axis | Indicator should move and steady out immediately. If it does not or oscillates just sitting there then you may have a bind or stick slip effect in your axis. | |
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Is it only in feed or in Rapid move? |
Feed- More likely to be a bind. |
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Does it alarm at an abrupt slow down? At end of Rapid move? |
Could be coolant in an electrical box on the motor or on one of the axes. Tends to splash up when it stops quickly. |
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Can you run the program at a slower feed rate without any problems |
Helps determine some of the factors above. |
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If you can run a sample long movement rapid program. Listen for a loud low growl |
Most likely bearings are bad. |
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Is there a hum coming from servo motor? |
Then there is probably a bind in the axis. Push estop pull back way cover and try turning ballscrew by hand. Use rag for grip usually pretty easy to turn and should feel smooth. |
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Put your hand on the motor to see how hot it is? |
If it is warm its ok. If it is too warm or too hot to keep your hand on it then there is a problem. |
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Put hand on Ballscrew? Handwheel then stop? |
If you feel oscillation ounce it stops or is sitting there then you probably have a bind in the axis and it can not position properly. You can also check to see if it bounce with an indicator. |
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