Auto calibration g29 sometimes crashing into bed

[raptor]

Hi All,

i just upgraded my rostock v2 to have an accelerometer board and i have noticed that if i run G29 to do the bed calibration from the terminal window it works fine, but then if i put it in the start section of my gcode and hit print, it heats up and starts and then crashes into the bed when doing the x tower (not just a tap but it overshoots and you get a grinding noise).

Any ideas what is going on?

Full setup:
Rambo board
firmware 92.2 (hotend selected at type 3 he280 w/accelerometer)
e3d hot end using this mount https://www.thingiverse.com/thing:2098268
seemecnc acclelerometer board rev 6
ballcup arms and effector plate
original cheapskates with ball end adapters
DIY berd air
slicer is S3d or matter control
i have also tried with astro print and it does the same thing

[pouncingiguana]

Depends on where in your starting gcode it is. You can't run either of the heaters when you're using the probe as the pwm signals interfere with it a lot. I'm guessing at least one of the heaters is active when you're probing. Can you post your starting gcode?

[raptor]

Ah that's probably it then,

i was just doing a G28 and a G29 to start the print but i think that the heaters were running. i'll do some tuning.

thanks