Looks like your Y axis is loosing steps… there’s a handful of possible causes… Carving into a Knot won’t help either as Knots are more dense than the surrounding Pine wood…
And to borrow some information from a recent response from Brandon:
I would check the following:
1. Ensure your feeds & speeds are appropriate for your machine & cutter & material.
2. Ensure there are no loose V-Wheels or other components.
3. Ensure that there are no loose connections on each stepper motor and connector at the controller.
4. If you have a router as a spindle, the lower the speed setting the better for most things.
Those are just some common issues/comments that cause machines to veer off the correct toolpath while carving. Toolpath Jumps Off Course During Cut - #4 by BrandonR_Parker
Your Masuter Pro (I have one of those also BTW) should use the following cut settings as a default semi “Go-To” safe settings…
Feedrate: 500mm/min (20ipm)
Plungerate: 100mm/min (4ipm)
Depth Per Pass: 1mm (0.04")
And the stock spindle RPM max is 10,000, so setting any higher is simply wishful dreams as it will not exceed 10K… you can leave at 18K if you want, but it’ll never go that fast…
So with these more conservative settings and ensuring the Belt Tension is taught wigthout being too tight, the carve should be okay to re-run.
Ohh one more thing, MAKE sure the Z Probe thickness is entered correctly into Easel>> Go To Machine>Edit Machine and at the lower left is the button to get into the Z Probe settings to see what the Probe thickness is set to, measure yours with calipers and enter the True thickness there if it’s incorrect.
One more thing, to get the best, most accurate, and quickest guidance on FoxAlien CNC’s go to FaceBook and Join their FaceBook Group>>> Redirecting...