Hard Z-Limit error - Locked (Smoothieware)

I have the same problem with a FabCreator cutter using Smoothie and GRBL

I tried to use the Z axis when attempting to identify how to focus the laser.

At some point I reached the highest position for the axis using the up and down arrows in the Move panel of LB

Since then I can’t use the Z axis button without getting the same errors

ALARM: Hard limit -Z
error:Alarm lock

This is very interesting.

Is the laser (or spindle) resting on the limit switch?

There is a pull-off or pull-back setting in GRBL and in Smoothie for limit switches. When the switch is triggered, the motor should reverse and ‘pull-off’ to return the limit switch to its original state. Please share the Smoothie config file or the Machine Settings $$ report from the Grbl profile.

If there is no switch on the axis where the laser (or spindle) has come to a stop. Please test to confirm that the mechanism isn’t binding and that the motor turns freely.

We solved the problem. By physically pulling down the bed, we released the switch.

A more knowledgeable operator than me used the belt (not sure this is the right term) to pull down the bed a bit, which resulted in making the smoothie happy again.

So I guess the switch got activated when trying to mount the bed too much and the motor didn’t “pull-off” enough to deactivate that switch.

Note that the smoothie didn’t seem to return the correct value for the Z-axis position anymore when the switch was activated. Always returned 0 when by experimenting we found out it was in approx. +18.3 position.

Also, I don’t know how the smoothie locking/unlocking works, but even with a Z-axis activated switch we could operate/use the laser on X and Y axis.

So, solved for me but the smoothie locking issue and feedback for users is confusing.

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Thanks for coming back to us with this information. I’ll move your contribution to it’s own thread so it will be easier for others to find.

Thanks again.

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