Re-surfacing waistboard problem

I was re-surfacing my waistboard when it stopped with 21 minutes left on the job. What can I do to get this finished?

If you must do this:

  • note what line the machine is currently sending (or determine where it was by measuring the deepest/farthest area correctly cut)
  • pause, then stop the job and shut things down
  • open up the G-Code file in a text editor
  • identify the preamble and copy it — see G-Code for the details of the codes
  • go to the line # noted above
  • scroll up from there until you find a move down from safety height
  • delete everything from the line above that line to the beginning of the file
  • paste in the preamble at the beginning
  • save under a new name

I appreciate your trying to help but I have no idea how to do what you suggested, I am very new to the machine and quite frankly a lot of this goes right over my head.

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What is the preamble?

As a newbie (4 1/2" years ago) this used to happen to me. Here was MY problem, and how I fixed it…

Even though the CNC code is correct, if you are sending it out of bounds…even a tiny little bit, the machine will stop. Because of the “look ahead” feature, it may OR may not be the lines showing on the screen. Now it could be in the X OR Y direction or BOTH. (fun huh?).

Try making the size of the rectangle a little smaller in X, or Y or both to fix the problem.


The preamble is that section of the file which sets up the cutting for the balance of the file.

Please post your G-Code and we can work through this with you.

This is something that bites new users a lot. They look at the specs and see an available cut area of, let’s say a basic Shapeoko 3 which is 16 by 16. They make a 16 by 16 pocket in carbide create and line it up on the front corner of the waste board.

The problem is that around 1.5 inches of that available cutting area is off the front end of the waste board. This means the 16 by 16 pocket wants to cut about 1.5 inches behind where it is capable of cutting. Carbide motion starts the job but when it starts to look ahead to see where to go next, it says “Nope. Can’t go there.”

Best bet is to push the router as far back as it goes and then measure from the bit position to the front of your waste board for the proper size.


Maybe modify to “total machining area x,y,z and work holding Area up to x,y,z”.

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