[Cairoid]

Hello, FNG here. I'm having some issues with my mill, thought I'd see if you guys had any ideas before I call in a tech.

The machine was drilling some holes in thin aluminum, when right above one of the holes before the drill cycle it errored out, throwing up an Error #24 Motor Overload. Nothing we did would clear this error. Checked seating on all the boards, checked all the resets and fuses. The last thing we tried was to reach in and manually turn the Z axis ball screw (the idea being to move the spindle up enough to be able to remove the tool so it wouldn't break if it decided to crash down). At any rate, as soon as we moved the spindle by turning the screw manually we were able to clear the error, bring everything home and cs the machine.

Next we tried running the program again. When it got to the same part in the program it did the exact same thing. Error #24 Motor Overload. Shut the machine down, climbed up, turned the screw a quarter-rev, brought it back up, and the problem cleared and we could home and cs. I replaced the tool with a longer one, thinking maybe that could make a difference for some reason? When I handwheeled the spindle down to set the tool length it moved most of the way but suddenly stopped. I could move the X and the Y axis but not the Z. After about 30 seconds it errored out the same way as before. We cleared the problem the same as before, but then shut down the machine and called it a day.

The next morning we tried to run it and it looked like it would be ok. The machine ran a few cycles of parts without problems. Then on the third cycle, (on a different tool than before) it messed up but in a different way. This time the program called for a Z+3" move. The spindle froze in its position, but the numbers on the display were showing that the Z axis was moving the positive 3". The machine never errored out, and acted like it had executed the move with no problem and continued to run the program. Major crash if we hadn't of caught it.

At any rate, we're stumped. I'd love to hear any ideas, suggestions, sympathy, etc.

Thanks!

[alex gitzel]

It sounds like the amp is going bad.swap with another axis and run a short test prorgam that will not crash use rapid and regular feeds moving z up and down and see if it faults,(test program) g0g90; z-5.;z0;g1g8g90;z-5.f200,;z0;m99p2; run awhile and see if it faults.you can downlaod a manual from fadalcnc.com if you need info on the swap.if it does not fault run the test on the axis the questionalbe amp is on.if this an ac motor machine unplug the motor wires and reseat them,and the ones on top of the cabinet above the amps if there are quick connects there also (some are solid wire).otherwise the motor or contol card may be having and issue but the amp is most likely.

[Cairoid]

I wanted to update what we've done so far. (sorry for the delay) After several rounds of troubleshooting we megged the Z axis motor, and it failed miserably. So we ordered and installed a new motor, only now we have another small problem.

After we installed the motor, we switched the machine on, and then released the emergency stop. As soon as it was released the spindle ran up in Z about 6" then faulted out. We hit jog to see if the fault would clear, and as soon as we did the spindle dived about 6" back down towards the table.

So we tried reversing the tach wires b/c of the runaway. When we powered up, the spindle moved up toward the CS position about .5", then stopped and gave us the ERROR #1 - MOTOR OVERLOAD.

So we hit JOG, and it would move up again about .5" and then error out.

After we did this a few time, the next time we hit JOG it continued to move up .5", then it would stop, then on its own move up another .5", then stop, then move up again. It repeated this process on its own until it passed the CS position, upon which we stopped it. So that's where we are.
Any suggestions?

[alex gitzel]

you also need to try the power wires,there are 4 possible combinations that need to be gone thru,just because they are color coded does not mean the guy puting it together is not color blind!!.another tip always test the motor with the coupling off.they can runaway and crash hard causing damage to the machine.also make sure the resolver cable is making a good conection on all pins.

[DareBee]

We are also assuming that you blocked the spindle before you pulled the motor.

[Cairoid]

you also need to try the power wires,there are 4 possible combinations that need to be gone thru,just because they are color coded does not mean the guy puting it together is not color blind!!.another tip always test the motor with the coupling off.they can runaway and crash hard causing damage to the machine.also make sure the resolver cable is making a good conection on all pins.

Thanks. We are scheduled to work on this machine this evening, so we'll try the different combinations. I'll check the resolver cable as well.

We are also assuming that you blocked the spindle before you pulled the motor.

Yes sir.

[denmar]

If you switched the Tach wires, the motor wires (black &red) should too.

[Cairoid]

So we're finally back up and running. The motor was left the in the same state as it was in my previous post, with the power wires wired normally and the tach wires reversed. We went through and checked every connection that we could, pulled the boards and reseated them, checked and retightened all the connections on the amps... Somewhere in all that whatever the issue was got fixed. The machine homed, we tuned the motor, ran a few test programs in the air with no issues, loaded up and ran. So I have no idea what the problem was but I'm glad we're back making parts. Hopefully that will be the last issue we'll have for a while (knock on wood).

Thanks.