Z-probe settings wonky

Hello everyone, I’ve been a long time original X-carve user and have recently upgraded my machine.

Approx 6 months ago, I started having issues with the depth of cut on my machine so decided to buy the upgrade kit. After the upgrade I ensured my grbl settings were correct and completed a series of test carves within easel to check the depth of cut. I set the depth to 0.125" and they all came out at 0.135". I reinstalled my machine, and checked the thickness of my Z-probe. Using calipers, my Z-probe is 0.590". In the set up, the Z-probe default is 0.590". I tried to cheat the machine and set the z-probe thickness to 0.600". This resulted in 0.145" depths - the opposite direction!. When setting up a new machine, I noticed all of my xyz axis were backwards. I reinstalled a new machine, but this time, I set my z-probe thickness to 0.580" thinking maybe this too was backwards. Voila! It cut at 0.125"

Using calipers, I tested a 1" movement in the z-axis and it came out to exactly 1" on the nose.

I went to bed happy last night that I got that resolved. This morning I fired up the xcarve and I was back to 0.135" depth of cuts!

Re-installing the machine with a z-probe thickness of 0.580" yielded 0.125" depth of cuts again. Why am I having to ‘cheat’ the machine into cutting the correct depth of cut? This is with the new z-axis.

My second issue was discovered today - I ran another test carve in Easel - a 1" square. It came out to a dimension of 0.985" x 0.985". How do I resolve this cutting issue?

Here are my grbl settings -

  • ok
  • $132=152.500
  • $131=750.000
  • $130=750.000
  • $122=50.000
  • $121=500.000
  • $120=500.000
  • $112=2000.000
  • $111=8000.000
  • $110=8000.000
  • $102=49.909
  • $101=26.660
  • $100=26.660
  • $32=0
  • $31=0
  • $30=1
  • $27=1.000
  • $26=250
  • $25=750.000
  • $24=25.000
  • $23=3
  • $22=1
  • $21=0
  • $20=0
  • $13=0
  • $12=0.002
  • $11=0.020
  • $10=115
  • $6=0
  • $5=0
  • $4=0
  • $3=0
  • $2=0
  • $1=255
  • $0=10
  • ok
  • [OPT:VMP+,15,128]
  • [VER:1.1g.20170629-Inventables:]

Thanks for any input anyone might have!
Rob

UPDATE : I was able to fix the XY issues. I did some digging and found a stepper motor calibration calculator made by JonLake here in the forums - Stepper Motor Calibration Calculator

But the Z-probe issue is still perplexing me…