How to crash a CNC router - Don't use the Resume feature

I am not a CNC router expert by any means but I have used Vcarve once or twice before at the makerspace w/ assistance & have been given a run down on the many ways to crash a Shopbot CNC router.

Today I learned a few new ones; A good reason to make the EMO/STOP button a bit bigger (GUI related & on the controller) & have it register a little bit quicker. There’s no good damn reason you should have to confirm an emergency stop on a tool…:expressionless:

As it turns out, going to the default work home (I assumed the CNC work home would center, not go to bottom left mistakenly) will crash the module (collet clamp, specifically) right into the frame of the Snapmaker. I managed to stop this as it was happening & measured the frame to see that no damage was done.

After leveling the work surface under the snapmaker a bit more from a bad test performance (something worth adding to the guide as common sense as it may sound, it clearly affected the cut), I went for a test cut 2 on the same piece.

DO NOT USE THE RESUME FEATURE. The controller assumed the Z-axis was at the top after the pause function & it was not; so the very first thing it did was run right into the piece, splintering the bit everywhere. I’m glad I was carving into 1/4" Birch & set the work speed to half (anticipating crashing is key) as thankfully I managed to stop it before it burnt through the bottom of the bit or hit the platform underneath… I should’ve known to just replace the piece & start over, but, lesson learned while I wait on more bits to arrive in the mail.

Off to the makerspace again…

Takeaways: Level work surface is key, always run your first cut at a 1/4 or half speed to watch for crashes & don’t trust the brilliant software to know its positioning should you have to pause the job.


I also killed the thin CNC bit in this way. Paused and wanted to adjust the clamps.
After resume the bit wanted to go through to the original waste plate. The work area was 10mm higher.
I therefore filed Issue 37.

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It should have a secure mode who detect collisions and stop immediately the machine! I had a calibrating issue when pushing on " go to start point" instead of “set origin” and thougt I broke something but the motors are OK

oh man i was just ranting about this on another post

if the print head returns to actual home position during a pause and power outage recovery scenario before it allows you to resume the project so it can properly determine where to go back to, since the positioining is getting jacked up it needs a starting point to figure where to return to from

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