BLtouch offset

Hi,

Looks like I printed the wrong mount for my BLtouch (the front mount in Michaels zip-file on Thingiverse). b9af237d00560a0d7fb2e634c43c840f_preview_featured|628x472

Best way to solve this is probably to print the correct one and rebuild the setup (which I will probably do next time something breaks), but it is working now and am just looking on getting the offset correct.

What is the best approach to measure the correct values?

– Eric

By using a terminal and the G-Code M114. Use a sheet of paper, align the nozzle with something on the paper (such as a cross you draw), get the current position with M114, move the head to align the BLTouch tip to this same cross and get again the position. Then do the math.

Sounds like a nice challenge. Will do that tomorrow. Thanks!

Have done the measuring and get this:

20:31:11.206: N54742 M114
20:31:11.216: X:99.00 Y:116.85 Z:1.38 E:-2.00 Count X:7920 Y:9348 Z:561

20:33:44.986: N54770 M114
20:33:44.996: X:89.40 Y:159.15 Z:1.38 E:-2.00 Count X:7152 Y:12732 Z:559

nozzle - x:99.0 y:116.85
pin - x:89.40 y:159.15

This gave me offset numbers of x:9.6 y:-42.3

When I put this values in the BLtouch settings for offset and do an auto-leveling I see the pin go to roughly the center of the bed, X-home, Y-home and freeze…

Display says “Homing…” and “In Progress”.
20190809_211411

When I go back into the setting and lower the x-offset to 7.4 all starts to work again. Setting it to 7.5 breaks it again.

Am I doing my math wrong or ??? Do have the feeling I’m trying to move the nozzle from the bed to the left.

It fails because your sensor positions are out of range. I will have to debug the firmware to understand why.

Is this fixed with #218 in 4.0.4?

– Eric

Yes, but no. Let me explain: i fix a bug, but it reveals another one. I am working on this. It is already fixed in the dev branch and will be in the 4.0.5 release.

1 Like

There are always more bugs… :wink: Thanks for looking into this.

Loaded 4.0.5 and I can set the offset just fine. Thanks for fixing.