Page 1 of 1

Added BLTouch - crashes into bed

Posted: Tue May 05, 2020 10:44 pm
by devachnid
Hi,

I've added a BLTouch probe to my A10. The wire colours are different to the 3DTouch, but I've managed to find wiring diagrams to check that I've connected it correctly to the 5pin connector on the hotend.

I updated the firmware using the file from Geeetech's website, and the BLTouch options now appear on the LCD menus.

When I power on the BLTouch self-tests successfully (pin moves in and out and red/blue LEDs change appropraitely), I can use the LCD menu or M280 commands to move the probe up/down without problem.

If I do 'Auto-home' the hotend moves down crashing into the bed and the stepper doesn't stop until I kill the power. This is despite the probe activating well before the nozzle hits the bed.

Any ideas why the z-motor isn't stopping once the probe is activated?

Re: Added BLTouch - crashes into bed

Posted: Wed May 06, 2020 9:59 am
by William
Hi,
It may be that the hot bed is too low. BL touch has touched the limit switch before it touches the hot bed and it fails.

Re: Added BLTouch - crashes into bed

Posted: Wed May 06, 2020 8:31 pm
by devachnid
Thanks for the suggestion, unfortunately that doesn't seem to be the issue. I mimicked raising the bed by placing an object on top but no difference.

Here's a picture of the connector and a video of Auto-home in case that helps diagnose the issue
Image
Autohome video

Re: Added BLTouch - crashes into bed

Posted: Wed May 06, 2020 10:16 pm
by devachnid
OK, so it was my error with the wiring. The colours are different to the 3DTouch, and I had connected the GND / Z-stop wires the wrong way around. Now seems to be working as expected (black and white cables reversed).