Bl Touch calibration problem

[Major]

When trying to set the M851 Z0 the printer always says
Send: M851 Z1Recv: echo:Z Offsetz_min: -15z_max: -5

Both of -5 and -15 bang the head into the bed and i cant set it any less than that. im guessing somewhere in the firmware it was set wrong just seeing if its posible to fix it without re flashing it.
it needs to be set like -1 or even +1

[AsianGuy]

What 3d printer are you using?
What firmware are you using?

I know for an creality ender 3 v2, the manufacturer OEM firmware is lacking. You can't adjust preset from the terminal, and a new firmware flash is required
Specifically I use Jyers Marlin code as a starting point and then modify various attributes specific to my machine

https://github.com/Jyers/Marlin/releases

If you're not familiar with coding or how to flash hardware, don't do it until you're sure, or you can brick your board

[Major]

What 3d printer are you using?
What firmware are you using?

I know for an creality ender 3 v2, the manufacturer OEM firmware is lacking. You can't adjust preset from the terminal, and a new firmware flash is required
Specifically I use Jyers Marlin code as a starting point and then modify various attributes specific to my machine

https://github.com/Jyers/Marlin/releases

If you're not familiar with coding or how to flash hardware, don't do it until you're sure, or you can brick your board

Its a GEEETECH Pro W Prusa I3 DIY.
i added the bltouch/3dtouch myself and flashed marlin already,
i don't really know coding i can kinda read it and work it out but not write it.
i followed this https://www.geeetech.com/wiki/index....eveling_Sensor
I understand that the specific part of code that sets parameters for the Zero offset is wrong but marlin has a lot of pages and i think it would take forever for me to narrow it down so i was hoping for someone outside knowledge.

[Major]

I didn't modify marlin completely there's a already setup firmware for my printer i just modified it says its Marlin-2.0.x

[AsianGuy]

@Major

Unfortunately I don’t know that system enough to offer any solid solutions – as I don’t want to risk slamming your nozzle into the bed or having it get bricked.

But Marlin is an open source software. It’s unlikely you would recode any other file other than “configuration.h”. There are situations on the Ender 3 v2 (which I own and typically expect most folks with crealitys to have bltouchs) where you would mess with other files to deal with the UI, but I don’t know if that’s applicable to your printer.

This might help you on your research:
https://marlinfw.org/docs/configurat...onfiguration.h
https://marlinfw.org/docs/gcode/M851.html

I’m not saying that the M851 g code is the where the bug/error lives, sometimes error messages aren’t the source of the bug, but I can’t exactly teach you computer science on an online forum. But assuming that is where the bug/error is…your solution is just to change the bound of z offset.

[Major]

Thanks anyways and i will check it out.

[Major]

Ok found it its at

// Custom M code points
#define CUSTOM_M_CODES
#ifdef CUSTOM_M_CODES
#define CUSTOM_M_CODE_SET_Z_PROBE_OFFSET 851
#define Z_PROBE_OFFSET_RANGE_MIN -15
#define Z_PROBE_OFFSET_RANGE_MAX -0
#endif

had to change them to needed values.

only problem im having now is the printer probes the bed before printing but when it does its second prob it only probs the middle( didn't do this before) and starts printing and is definity not reading first probing values as a big print had obvious low/high bits on bed.
so obviously it knows its boundary's for probing just doesn't read them for some reason. i guess another day another problem.

[AsianGuy]

@Major


Unfortunately what you described is a little vague and without knowing whose base configuration.h file you used as a template, it’s impossible for me to troubleshoot


However based on what you stated, is it possible that it’s your slicer?


Your slicer produces the majority of the g-code that the printer uses to print the model you’re making. However at the start and end of the file, it also puts in various lines of code to do house keeping stuff. Some of these code might say probe the bed, load the bed mesh, produce a wipe line to clean the nozzle before the print, and move the nozzle a safe distance away after print. What you described about probing the middle, suggest that the printer was homing itself to figure out what the z offset was. In this way it can get the “right” height for a good initial layer adhesion to the bed.


Now if what you’re saying is you want the system to probe the bed before each print, there are g-code you can enter into your slicer to tell it to do that. But that also involves you setting up which method of bed probing you want, bilinear vs UBL.


I certainly understand some of your frustration. Commands can come in from the slicer or the firmware (or even both), so trying to figure out where it’s coming from can be a daunting task without experience. I will say this thought…if it works…and it ain’t broken…don’t fix it.

[Major]

Well i'm just a idiot i changed my slizer template to petg and it deleted the starting gcode to make the printer probe before starting. Thanks for reminding me tho saved me a lot of time.

[AsianGuy]

@major

Glad you found the fix

Always feels good to resolve a problem