My broad question is: how do I make a job start and stop while being certain the router won’t go outside of the area I’m machining?
The example is, I’m looking to drill precisely-spaced holes in the bottom of a plastic tub. The tub fits in the shapeoko, but if the CNC decides to rapid to the front or the bitsetter, it would crash into the wall of the tub on its way there.
Is there a way I can be super sure that it won’t rapid at the end of the job, and that it won’t bit set? I’m assuming if I only choose one bit, it won’t, but again, I want to be more certain of this.
@WillAdams What’s the pocket toolpath for? If it doesn’t end up as part of the G-Code, I’d assume it wouldn’t change the operation of the machine.
I guess my broad question is, what determines when the Shapeoko decides to rapid to the top center or the bit setter? Definitely disabling the bit setter setting is something I should do. Are there other situations where Shapeoko will make movements outside of the strict instructions in the exported GCode?
Would it help to use something like UGS and GRBL instead of Carbide Motion, since it isn’t aware of the bitsetter or other things? Or are the tool change movements done by the Shapeoko itself?
You could edit the gcode with notepad, and edit out the commands for it to home, etc. Check the code without the part on your table to make sure it runs correctly.
Ah I see. The tub is taller than the bottom of the tool when fully retracted, so mainly I need to ensure the machine constrains its movement to inside the tub. Even fully retracted, it’ll crash into the wall of the tub if it tries to move outside.
Oh, here’s a different idea. Is it possible to fence the machine so it never moves outside a given rectangle?
I think a lot of my confusion is not knowing whether it’s the GCode, Carbide Motion, or the Shapeoko itself that does moves to the bit setter, or rapids to front center, for example. I haven’t found clear docs yet on what the Shapeoko or Carbide Motion do beyond what the GCode says.
Once you generate the GCode, hand edit it and remove “M02” at the end of the program. When CM sees a “M02” it tells the machine to retract and go to the back.
You can always create a test program, with one hole, and try it without the tub in place to make sure the machine is acting correctly. For the test you can set the Z so it’s too high to drill into anything.
Is it a lot of holes?
If not you can just do it manually with G0 moves between the holes and run the hole drilling operation as G91. Then you can be certain that it does not move i to the tub, well. if you don’t command it to do so
Edit: this post by @neilferreri explains it quite well.
It’s a TON of holes. But it turns out I’m going to go with a simpler solution.
I learned that my Pro XL can machine in front of itself, so I’ll build a mount, and drill the holes with the bin upside down. Then I don’t have to worry about crashes.
