So a few months ago I joined the Bambu family, after over a decade of printing with much more ‘manual’ machines.
On a recent customer project, Z offset changes to fine tune the first layer of a print were found to be necessary. The print is an ‘engraved’ placard with text, printed text side down on the bed, 0.2/0.4mm nozzles both tested. I have had to print the model, watch the progress and cancel if the Z offset isn’t quite right, then changing the Z offset in the gcode, reslicing, resending, printing, rinse/repeat.
This process was PAINFUL. It’s probably my biggest gripe since moving from Creality to Bambu.
Recently Bambu moved the Z offset feature into the P2S user interface. I was overjoyed…only to find it is not available whilst printing…
What? What is the point of that? Why wouldn’t they allow it whilst the print is in progress, like every other machine I’ve ever used?
The issue is that the accuracy of the P2s bed levelling is not sufficient enough for this type of print.
This is why we need 0.05mm live adjustments, like every other brand of machine. It’s not a flow calibration issue, if it was, I’d have repeatable results with the same settings…
OP, I don’t think you’re the one getting the memo.
As you said in the first sentence of your first post, Bambu isn’t a manual machine…and then you proceed to argue with everyone that it should be a manual machine.
You’re coming into this with a frame of reference that doesn’t apply here. There is no Z adjustment, and THERE SHOULDN’T BE ONE, either.
In Bambu printers, the print head uses a force transducer to probe the bed, mesh the bed, and set the Z height. If you disable bed leveling before print, it still will probe to set the Z height in the center of the bed prior to starting the print.
There is literally no reason on a per-print basis to modify Z height, and there is certainly no reason to modify it dynamically during a print.
You can change the initial Z height in the slicer under Quality, but I don’t think that’s what you’re after.
Now, with all that said, the real issue is that you’ve got a problem and you’ve come up with what you think is the solution and are demanding that solution, even though it doesn’t exist and millions of users are perfectly OK not having it.
How about instead, you explain the problem you’re having, and we can offer advice on how you can solve it within what Bambu actually can do?
@Ikraus is right. You have two knobs in the Bambulab slicer that can get you an equivalent result to changing z-offset. One is initial layer height. The other is initial layer flow rate.
It’s fine to ask why Bambulab didn’t implement z-height, but it’s academic. For whatever reason, they didn’t choose to do it that way. Z-height is an easier concept to grasp intellectually, but the important thing to recognize is that the alternatives leave you no worse off. Do a “perfect first layer” calibration and you’ll be golden.
I agree with you, but unfortunately it’s a futile battle over here. Somehow everyone believes that Bambu printers use some sort of magic that makes it immune to z calibration issues lol. But a lot of the underextrusion complaints we had before the latest firmware was because of z offset isues.
To that end, I’m surprised that Bambu actually implemented a z offset calibration feature in the recent firmware. I was resigned to manually changing the Z in gcode.
Bambu’s brand is built on top of hiding technical controls from the user, and replacing them with autocalibrations. This doesn’t explain it away, and I think it would be very useful too, but I dont think its realistic to expect. If they put the control in, its an admission that their systems arent perfect and marketing can’t have that
“As you said in the first sentence of your first post, Bambu isn’t a manual machine…and then you proceed to argue with everyone that it should be a manual machine. ”
You’re pushing that a bit far. I am definitely a fan of the many automations that the Bambu ecosystem has. For the average Bambu customer that wants to print pre-sliced dragons and trinkets, this machine is a dream.
But the fact still remains that this machine failed to achieve a task so many times, I’m talking ~100 hours of print time wasted.
If your statement is true, I should be able to perform this print 10 times, and get the same result 10 times. The fact of the matter is, the ‘auto’ Z axis precision is not perfect, and that is why I’m not getting the same result for this PARTICULAR model. I am not new to FDM printing, this is my 5th machine in over a decade of printing and designing parts, and I’ve not struggled with first layer precision since the early days of Reprap!
Bambu have just implemented Z axis adjustment into the machine UI, which is unavailable during printing currently. Besides aftermarket build plate compatibility, why would they do that?
Yes, that’s exactly how this works! I do small, medium, and large batch production work on my X1C and I get the same result ten, twenty, thirty or more times in a row.
Z offset adjustment isn’t needed for aftermarket build plates, I use Darkmoon, Bambu, WhamBam, and Biqu plates and never adjust anything. Two weeks ago I had an extra dull moment and didn’t put a build plate on at all and it STILL somehow managed to print the part!
…and I have yet to see a particular model that needs adjustment, nor can I even envision part geometry that could drive a need for such fine tuning.
I just don’t think you’re fully grasped why Bambu is so successful. They eliminated all the stuff that added up to make 3D printing finicky and miserable and not attainable by the masses.
Why don’t you share a bit more about what you’re printing and exactly how it’s failing? Like you, I’ve been doing this for awhile, and I’m telling you this doesn’t quite add up.
Does your part require a perfect first layer? My 3d prints are mostly faceplates and covers that are printed face down (and in PETG and ASA) and any minor variation (eg slightly over squished lines, etc) would be unacceptable. For example the minor “tiger stripes” below in the print below would be rejected.
Some of my parts are cosmetic and the “good side” is printed against the build plate. I use the Bambu 3D effect plates, too, which are probably the most unforgiving surfaces to print cosmetic against IMO.
I’ll be honest, though, that design of yours shouldn’t be doing that. I print a certain design in PETG HF and although it’s the underside, it’s flawless. That variability you’re seeing is really sus, and I don’t think it’s down to bed leveling.
Thanks for the responses. I should have written this from the start.
The intent was to make a replica of a traffolyte label for electrical distribution board labels. The standards of labelling are quite strict in my country. This is essentially a plate made from a polymer, which is essentially a glossy, white layer of plastic that is bonded to a black substrate. A machine then engraves the text, penetrating the white layer and revealing the black substrate. So Black letters on a white background.
The purpose of 3D printing was to make amendments on the fly and recreate the engraved label, which would normally have to be ordered, manufactured and shipped. I had the opportunity to charge a handsome fee, due to the ability for a next day turn around. What resulted, cost me much more time and money than it was worth.
To make the label, the image/text is converted to SVG, then extruded (cut) into a flat, rectangular plate in CAD, then the two colours (black/white) added in the slicer.
So, in a nutshell, engraved text is being printed face down, very finely with an 0.2mm nozzle and 0.08 first layer for crisp text. I tried it with PLA, PETG, ASA.
The first layer appearance would be different EVERY print due to the small variances in Z precision. It would possibly never be a problem for most models, but it was for mine.
I have managed this type of precision with much less advanced printers in the past.
The P2S auto Z axis tolerance is 0.01mm at best. Old fashioned live Z microstepping on a crappy Marlin based machine allowed 0.0025 mm/step. That is 4x the precision. That makes quite a different to the ‘squish’ at small layer heights with a small nozzle. I just want some control over that precision.
This would be an excellent project for a makera carvera or similar. Comply with the regs and just use the printer to print a blank slug with those white and black layers as specced, and then actually carve it with the cnc so it will be legible. Idk if that’s what you wanted to hear but….
and marketing can’t have that 
