Enable fade of Auto Bed Leveling

[DzzD]

Marlin enable to use the special command M420 S1 Z10 to fade the ABL on a certain height, would be very nice if this was possible on Bambulab Printer to use this gcode or another to use fading on ABL.

For example :
M420 S1 Z10

Would mean that ABL is used

• 100% when z = 0mm
• 50% when z = 5mm
• 0% when z = 10mm (at this point ABL may be disabled too)

Note that this fade can be done within the firmware using a special gcode or in the studio by modifying the generated GCODE when slicing.

[Majestic7979]

Can you explain why this is even necessary? With a solid example. What hurts the print if this isn't provided?

[DzzD]

Can you explain why this is even necessary? With a solid example. What hurts the print if this isn't provided?

heuuu... strange question, but yes I can, it's a well know option in slicer and/or firmware, it make the part perfectly flat at a given height, and then the printer can act exacly like if the printer bed was perfectly flat, but that's only one advantage.

For example on a completly warped bed you can print a raft that is 5mm thick and with a z fade of 5mm, it will be perfeclty flat on top even if the bed is completly warp, but there are tons of other usage, just do some search, it is not mandatory, but like many options like bed levelling, this is a very basic feature wich all good slicer or firmware should have...

Another exemple is that when you have cut two parts and want then to clip perfeclty on their top surface by the plug you create/added, etc, etc...

[Majestic7979]

Ok thanks. It's not a strange question. I wasn't aware of what this option was for. I saw it on Klipper when I was building my config file but never really occurred to me that it would affect stuff. So basically you're telling the printer to fill the gaps at the top from what I understood of your explanation so that it ends up flat. Is that because you assume that the part won't be flat unless there is fading? Or is this actually documented in firmware?

[DzzD]

You ask the firmware to reduce ABL correction each new layer until there is no more need of ABL as layer are totaly flat, it is usally set from 4mm to 10mm :

With Fade height enabled, bed leveling correction is gradually reduced as the nozzle gets closer to the Fade height. Above the Fade height no bed leveling compensation is applied at all, so movement is machine true.

Source : https://3dprinting.stackexchange.com/questions/20830/what-is-the-fade-height-option-in-marlin

[Majestic7979]

Cool. But if the levelling is applied all the way how does it affect the part? I printed a 40x40 cube and my caliper is showing exactly 40x40. I printed 5 cubes in different areas of the bed in total. They are all 40x40. Not sure how this is going to help?! I guess if you explained your use case more clearly they would pay more attention.

[DzzD]

They sure know about this feature as it is a common feature in FDM printing... but anyway it is not a self service, I have posted this issue because I think it will be a good for the Studio, not for myself, I can live without

[DzzD]

Anyway, I dont really understand what you are trying to teach me, and why you try to explain me how this and the world should works, I created my first public opensource project back in 2005. They can gently ignore my isssue if they find it useless for the community.