Micromill jammed when homing

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Benny
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Micromill jammed when homing

Post by Benny » Thu 13 Sep , 2007 13:10 pm

Problem: I attempted the "homing" sequence and it appears to be jammed on my Micromill.

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bradders
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Post by bradders » Thu 13 Sep , 2007 14:14 pm

Resolution: Take the back off the machine and check the LED status display on the control card. With the power on, what is on the display and what color is it?
When the machine was homed, did the axis go up to home position and then go down? Or did the axis just travel very slowly down? Or did they go up and stall against the end of the rail?
The Home switches may be the problem. Vacuum out around the switches and use compressed air to blow out any debris from around the switches.
Try pressing on each switch lever, you should hear/feel a click when the contacts inside the switch open/close.
You can check the switches with a volt/ohm meter, set on ohms or continuity. With the switch in normal position the contacts are closed (circuit), when the lever is pressed down the contacts open (no circuit). The switch may have gone bad and needs to be replaced. Also check the wires and connectors that go to the switch, they may be loose, dirty, or the wires are cracked.
When the machine goes Home, the axis moves toward the switch, when the switch is pressed and the contacts open the machine moves very slowly (creeps) away from the switch. When the switch closes the machine knows it is at Home and stops.
If too much oil was used to lubricate the machine, the oil may have gotten in to the switch and coated the contacts.
You can try the “secret home” function to move the axis away from the home switch – see link viewtopic.php?t=53&highlight=secret

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Steve
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Post by Steve » Thu 13 Sep , 2007 14:50 pm

I went to one recently where the screw locking the Gib strip was loose and the strip had jammed solid.

Try homing each axis independently and find which one is jammed then look for a machanical solution.

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