UGS losing zero

I have had a continuous problem with UGS losing zero. This especially happens when running one job after another. One file finishes, the machine returns to zero… then I run the second file, but afterwards it just stops at the position where the file completes its last line of code. If I hit the RETURN TO ZERO button, the Z axis goes crazy and goes up (+) until it crashes… UGS keeps sending commands… it never returns to zero. After this happens, UGS has lost zero and I must reset. Even if I’m 0.1mm-0.2mm off on the reset, my project (which at this point has been running in different stages for several hours) is basically ruined.

I need to be able to run multiple files with the same zero… so I can do tool changes after one file completes for use with the next file. And–also so I can use the Tile Toolpaths feature in V Carve Pro.

I have resorted to drilling a “zero hole” with the first bit I will be using so that I can line up the bit in the hole and reset if UGS freaks out. There must be a better, more reliable way.

The UGS “Return to Zero” button uses the G28 G code command. This is a position that is held in the Arduino EEPROM and doesn’t change even when the machine is powered off and back on.

To use the “Return to Zero” you need to set the position for G28.

Power on you machine, home the machine, jog to the location that you want to be zero and enter the G code command G28.1

This sets the position in Machine space. Now any time that you press the “Return to Zero” button the X-carve should move to the location that you set.

This procedure only works if you have the homing switches and home your machine when you power it on.

You dont need homing switches for G28.1 to work.

Technically no, but if you don’t use the homing switches then you have no mechanical reference for Machine 0,0,0 when you start your machine.

If you just started your machine and issue a G28 you are going to send it “who knows where” and may cause a crash.

To keep things simple I just recommend homing as that keeps new people out of trouble.

If you set Machine 0,0,0 manually then the G28 would operate in reference to that point (which may not be the reference point you used to set the G28.1 point). In this case you would not need homing switches, but that means that you have to manually set machine zero every time you turn on your machine in order to get repeatability. Easier to just home.

Just snapped off my last 1/16 bit when ugcs ran into the top of the z and on restart ran the bit into the waste board. It worked fine through out the day and then went haywire.