Hot end keeps crashing into build plate

[slate fjord]

Hello I am trying to print the final parts for my Voron 2.4 and am having problems with the hot end. everything works fine when I run homeing commands and QGL. However when I start the print the hot end will crash into the print bed and it will lose no longer use the full bed. I am using Prusa Slicer

[earnest marten]

can we have your printer.cfg as well, please

[earnest marten]

oooof, looks like a bent revo 😟

[slate fjord]

it is now and it was a revo obxidian

[earnest marten]

so, you have this in the SAVE_CONFIG section at the bottom of printer.cfg (lines 908-909):

#*# [probe]
#*# z_offset = 8.404```
but you don't appear to be using the probe as your endstop, you're using a physical z endstop

delete the above lines, then in the other `[probe]` section, uncomment `#z_offset: 7.538` (line 322) and set it's value to `0`

then re-run the [z endstop configuration](https://docs.vorondesign.com/community/howto/120decibell/z_endstop_configuration.html)

if it asks to save to either "z endstop" or "probe", make sure to select "z endstop"

[slate fjord]

I followed the guide you provided but when I run Z_ENDSTO_CALIBRATE
I get to Z position: ??? —> 1.999 <— 2.999 and the z axis moves down then back up

[earnest marten]

down then back up or up then back down? up then back down is normal

not sure what that video is trying to show, i see no movement at all

[slate fjord]

@earnest marten You can barely see the belt move down then back up

[wooden nebula]

does the gantry go up though? You'll have to be way more stable for that to be obvious on video. but yes as you do small movements it goes up and back down to make sure binding doesn't lock things up since we are looking for 0.1mm or less

[slate fjord]

I followed the calibration guide and preformed it a few times till it passed the verification step. However when I try to tart a print it doesn't touch the build plate

[earnest marten]

let's have a klippy.log

[earnest marten]

you don't have zero_reference_position defined in the [bed_mesh] section

[slate fjord]

@earnest marten ok so is zero_reference_position: 150, 150 ok for a 350 build plate and should I rerun the z endstop configuration?

[earnest marten]

that'd be fine for a 300mm² build plate 😜

[slate fjord]

lol ty

[minor oracle]

you want the zero reference to be one of the points of the bed mesh, which is the reason that you use uneven numbers for the bed mesh (5x5, 7x7, 25x25 ...) and the center point of the bed (for a 350 bed thats 175,175) as zero reference. Once thats all fixed you should definitely run all the calibrations (including Z switch offset) again.

[slate fjord]

@minor oracle I will rerun all of the calibrations again and try a test print with the new values

[earnest marten]

just setting zero_reference_position shouldn't affect previous Z_ENDSTOP_CALIBRATION, but no harm in doing it again

[minor oracle]

shouldn't =/= won't
😉

[earnest marten]

ok, i'll rephrase that, just setting zero_reference_position won't affect previous Z_ENDSTOP_CALIBRATION, but no harm in doing it again 😉

[slate fjord]

It seems to have finally worked thank you all for your help it was greatly appreciated. On a slightly unrelated note is it possible to straighten this nozzle out

Oh and will using automatic z calibration (https://github.com/protoloft/klipper_z_calibration) be a good idea?

[wooden nebula]

What probe are you using?

[earnest marten]

i thought it was a good idea, but, ime, more hassle than it was worth

[slate fjord]

@wooden nebula I am using the klicky probe

[earnest marten]

you might be lucky in straightening it, but i probably wouldn't trust myself not to snap or crush it

[slate fjord]

@earnest marten yeah ill probably just save up and buy a new one

[earnest marten]

probably for the best, however much it hurts your wallet

[minor oracle]

used it, its nice but only neccessary if you frequently change build plates. (or if you use different sides of the same one).
I only ever use two sides of the same plate, and usually stick with the textured side. ended up removing the auto Z stuff and just changing the value depending on which i was using (two lines under each other in the config, one commented out).
Now i have a bed scanner with nozzle touch, so it doesnt matter anymore.