Possible idea for Carbide Motion to check for slippage

[Stankus (John Stankus)]

Occasionally, I have had issues where I have had a bit slip in the collet and pull itself into the work. (I have that happen a lot less now that I have more experience) but I had it happen the other day on a long carve building structural pieces from 2x lumber for a filter box for my AC.
Since I had a suspicion that there might have been an issue, it occurred to me with the pause functionality it might be possible to have a verify tool length option.

How this would work would be

1. If you were suspicious of tool slippage or lost z steps, hit pause
2. in pause mode, there would be two options: resume (a bigger button would be nice) OR verify tool length
3. If verify tool length is chosen, the tool length would be remeasured
   3a. if the length was correct the Resume button would appear (maybe a message so tool length verified)
   3b if the length was incorrect a warning would be sent, something like “WARNING: Tool slippage or lost steps”
4. The recovery process would have to be thought out. If it was just slippage in collet, there could be a remount, remeasure, continue sequence. If it is lost steps, I am not sure on the recovery process.

I was thinking slippage in collet would be longer, but that may only be for upcut bits. I’m guessing lost steps would be usually shorter (collet nut hitting an adjacent feature etc). Might be enough just to know things are off, and the individual has to workout the recovery.

Just a thought.

John

[mhotchin (Michael Hotchin)]

Unfortunately, when the machine is ‘Paused’ (GRBL calls it Feedhold), the controller can’t do ANYTHING except either resume, or abort.

So implementing this would mean either abandoning the the Feedhold and managing mnaually (somewhat difficult because of things like the planning buffer), OR moving to more capable hardware so that the functionality could be included in GRBL itself. For the second, I don’t think the developers want that functionality, so it would be custom work.

[robgrz (Rob Grzesek (Carbide 3D))]

We’ve toyed with this idea for years, and we even made some modifications to GRBL to do it in X/Y as well. But when we draw the Venn diagram of “People who need this” and “People who would use it before they ruin their setup and we can no longer measure it”, we don’t think there’s much overlap based on the support tickets we get.

Our position is that there’s no substitute for experience, and, barring that, we’ll default to toolpaths that are harder to set up wrong, like the new Cutout toolpath.