Hi, I am running the CNC for the first time and need help. I am having issues with the CNC head seeming to loose its position in the Y direction more and more as time progresses. It is going farther up and down in the Y direction then it should be (working in Fusion).
This is how the cut is coming out, the bottom length is not a straight cut like it is supposed to be in simulation. The cut out lower in depth is slowly moving upwards in the Y direction.
On the lower right length, the cut is straight, but as it get to the right side it is 2 or 3mm off.
I have tried slowing the work speed down, lowering the maximum roughing stepdown, lowering the maximum stepover, and tightening the two lower linear module’s slop. None of these changes made a difference, and the ones that increased machine time actually seemed to make it worse(Top cut out in picture). Could this be an issue of backlash compensation?
Need to share more info. Saying you slowed down or lowered step-down doesn’t mean much if we don’t know where you started from.
Need speeds & feeds, settings etc.
What cutting paths are you trying to use?
If you can share the fusion project file that can help. (may need to use an offsite server or zip it)
It’s not backlash. Backlash doesn’t make that large of a difference.
Unfortunately it says no attachments allowed because I am a new user, but here is a share link from Fusion hopefully that is useful. I might just have to setup offsite server.
I am using the 1.5mm flat end mill bit, spindle speed 12000rpm, cutting feedrate 400mm/min, and all of the stock settings for this tool bit set up from Snapmaker library.
I have the operation split into two tool paths, a 2D adaptive cut for the deepest cut, and a 2D pocket for the shallower cut.
The 2D adaptive path settings I’ve changed are 1mm maximum roughing stepdown(Also tried 0.5mm stepdown), and ramp is set to plunge.
The 2D pocket path settings I’ve changed are 1mm maximum roughing stepdown, and ramp is set to plunge. I also tried changing the Maximum stepover from 1.425 to 1.0mm.
I’ve also tried setting work speed via the Snapmaker controller to 80% instead of 100%.
Have you loaded the snapmaker machine config file and selected the SM as the machine under setup?
Not seeing that when I check out setup. Not sure if that’s just from loading someone else’s file.
That’s the only thing I can see. Everything looks like it should be okay. I usually set lead in/out the same and a little less than cutting rate.
I’ve found I don’t really like using adaptive with my SM (especially with 3d (I only run 2d for contour and engrave)) I find it sometimes gets too aggressive for the power of the SM. It doesn’t know the SM isn’t a real cnc and that it’s underpowered. Tend to stick with pocket.
You’ve tried 3d/laser and they work fine? No problem with losing steps?
FYI, you could save a lot of time using 3d for both but running the toolpaths in opposite order and using a 3.175mm (or even 1/4") for the first and then have rest machining turned on for the 1.5mm. That way it won’t try to cut what’s already been removed.
I finally got a straight cut!
Setting both the lead in and out feedrate to 400mm/min and doing only 2D pocket cuts seemed to fix the issue.
It turns out I never loaded the SM machine config file and I wasn’t able to find any downloads from SM to set this up so I left it unselected. I only set up the post processing machine config files.
I will have to try out rest machining too and save myself some time.
Thanks
