Need Help!- Bridgeport Explorer X Axis Not Repeating From Home Position

[minton]

Bridgeport Explorer, DX-32 Control

When the machine is shut down, restarted, homed, then positioned at the previous X 0.0, Y 0.0 the X axis does not repeat. It is usually off by a -.100

I think this is called grid jump. How can this problem be resolved?

As always, Many Thanks for the Help!

Regards,

Bob Adams
989 798 6581

[EFI-Unlimited]

Is it off by exactly .100?

I would look in your service manual, under x-axis motor replament. In there, you will find a spec for when the x-axis home switch should 'make'. Go to the maint prog, and verify this contact closure is within spec.

Brian

[gus]

happens on my r2c3, I think it is as mentioned above, when the encoder ref mark is too close to the trip dog, it can miss it[IE one time it hits the trip dog before the ref mark, the next time after] resulting in an exactly .100 error

[MetalicGlow]

Originally Posted by minton Bridgeport Explorer, DX-32 Control When the machine is shut down, restarted, homed, then positioned at the previous X 0.0, Y 0.0 the X axis does not repeat. It is usually off by a -.100 I think this is called grid jump. How can this problem be resolved? As always, Many Thanks for the Help! Regards, Bob Adams 989 798 6581

My TC-22 with DX32 control has done this exact same thing for years - X axis only, and about .100" off like yours.. It does not do it often, but often enough that I ALWAYS reset the X datum after each boot up.

[EFI-Unlimited]

Instead of .1, could it be off by 0.1575? If so, then it is almost certainly the above mentioned problem. This assumes you have the 8mm pitch screws on X+Y.

Brian

[minton]

Brian:

When it is off...it is always off by approximately -.100.

Regards,

Bob

[TimC]

When the dog hits the home switch the motor rolls back to find the pulse marker. Depending on how close it is to the marker the motor may back off 1 full rev. Try moving the dog one way or the other around 1/16th of an inch and see what happens.