I’m new to inductive z probing with Marlin. Has anyone see this behavior?
The bed is fairly level but the z probe auto level has decided there is a couple degree slope as you can see in the photo.
I saw this. My Z motor was skipping during the G29 auto-level command, probably because it was undersized (from a previous revision of the kit). Probelm went away when I replaced it with a large Kysan.
I can imagine two ways this can happen, one as Patrick mentions the Z axis slips, and two there is something ferrous on part of the build platform that is confusing the inductive measurement. Now you have me interested and I have to go look at how they sense the position of the build platform 
@Patrick_Ryan ya I have the under sized old motor. I reduced acceleration to 7 and it works much better. May have to drop accel more though because sometimes it probes well, other times tries to, smash the head. The probe itself seems to be in consistent about when the led comes on. Doing further testing.
Can I know the specs of your motor? I would like to know if I need to upgrade my z motor.
This happens to the one I am road testing as well (printrbot simple metal ). The hot end fan bolts seem to catch on the frame at the first probe causing the probe to be off a bit. Replacing the bolt with a smaller one would help.
@Jeremy_G_WeisTek_Eng I taped the 1mm spacer on the back of the extruder motor and avoided that hang.
Unfortunately using the medium motor from old printrbot doesn’t work well in the extruder. When I turn up the current enough to stop it skipping, then it gets hot enough (or the hotend) that the ALU guide melts the PLA causing a spiral glob above the extruder. Ordered 2 more kysan motors. Hopefully that will fix the problems in Z and E.
@Dat_Chu The new motors are Kysan 1124090 NEMA17 stepper motors. The old medium size one is shorter by 6mm in the body.
@Alan_McNeil wow. Those are 60Ncm? Comparing to mine at 40, that is very good.
@Dat_Chu yes a big improvement over the 40s.