Plunge Into Work Piece After Surfacing Operation


Was using the LM yesterday and everything was working fine. Then I used Gsender to surface a workpiece, which completed properly, but when I loaded the next toolpath and ran it the router plunged straight down into the workpiece even though everything had been zeroed after changing the bit.

Is there a need to reboot Gsender after a surfacing operation? Tried it a second time and had the same thing happen the next time I tried to go from Surfacing to a Toolpath.


I’ve read problems with Gsender day after day after day on this forum. At least it sounds like Gsender at the outset. UGS was recommended to me by the SIENCI folks when I bought my Longmill 2 years ago. I use my machine almost daily and have never had a problem that I can attribute to UGS. Gsender may need some time before it is bug free.

My thoughts as well so I installed UGS and got exactly the same result as with Gsender.

When this has happened to me it is almost always attributed to a step I missed in my setup for the cut. I would check your process and ensure you’ve zeroed the Z axis especially if you’ve switched from a surfacing bit to a different one. I’d do separate tool paths for surfacing and your other operation. I’ve been using gSender successfully.
Hope that helps.

Sorry to hear SciGuy. I hope it hasn’t ruined the workpiece. If it’s snot Gsender I would have to agree with dmo. You “Z” zero will be different of course but with the resurfacing “Z” the opposite should happen. You bit should not go deep at all. There are people on this forum far more experienced than I at this and your post will be addressed I am sure. Recheck you settings from your CAD program and then methodically re-do your set up as dmo suggests. I also use a completely separate tool path for resurfacing.

@MajorSciGuy Since you have the same issue with gSender and UGS, I believe it’s safe to conclude that the sender is not the problem. That leaves two things to check out as I see it. Your gcode and your set up. It sounds like your physical set up is good. You are re-setting Z0 with the bit you will use for your project. So that leave the gcode itself.

What CAM software are you using to generate your tool paths?

I am using Fusion 360.

I turned everything on this morning and tried to run the same files with no problems. That makes me think it’s not the code.

Is it possible that I am powering up the Longmill incorrectly? The issue seems random but persistently shows up.