Originally Posted by
robertk925
I am guessing that your stepper direction settings are reversed.
As Downunder35m says, follow these steps (with one important change, do step #3 instead of reversing the stepper connectors):
1. Manually move the laser head to the center of the bed.
2. Keeping your hand on the power switch, turn on the machine and see which way the head starts moving (the machine always tries to find 0,0 home when first turned on). It should move towards the left-rear. If it doesn't then quickly turn off the machine.
3. Using RDWorks, go to "File/Vendor Settings". (The default password should be "RD8888".) For "Dir Polarity" and "Limiter Polarity" switch the setting (e.g. if it is currently "Positive" then switch it to "Negative) for either/both X and Y.
4. Keeping your hand on the power switch, turn on your machine again. It should now try to home to the left-rear, which is where the home switches are located. If it does so but still gives you the jack-hammering, turn off the machine and check all of the wiring to the home switches.
-robertk925