Hi everyone,
First post hear and I really need help, tried to solve it, but have no clue anymore.
I have an issue with a big print. It’s a relatively simple shape and it works well at a smaller scale. But when I print it filling the build plate I get layer adhere problems when the rim starts printing on the huge flat area. Always at the same spot, close to the fan on the side. Could that be the issue?
Tried it in ASA first, thought that might be the issue, but had the same problem with PETG, which works perfectly, usually, but was even worse.
Silly question I know. But did you do the auto calibration before you ran your part? Now that you have answered “YES RobBob” is your meterial from Bambu Labs. Are you running them through the AMS or off the Back spool holder? Lets go with you are using a different brand then Bambu and off the spool holder. If I am wrong we will work on that later. The the area where the meterial is left mouse click on the location of the spot the new meterial will be used. ILL WAIT. now from this list go to the bottom. “Add remove what ever”. The screen pops up with everything Bambu Likes. Upper right “Custom” That you. Click you want a new one. Fill out everything you can. At the bottom Choosing a filament from Bambu closest to yours. And save all the way out. Now put this up from your list to the slot you want to use it. The pin to right of it is there to set the filament to the vendors specks.
I know this is long and it sound tougher then it is. I just put all of my Sunlu and MIKA3D in to the list with serial numbers. AND WOW what a difference it made on some of the tougher prints I had on a prototype motor.
No, I haven’t done the auto calibration yet, but it might be worth trying. The lower half of the print worked perfectly, as did the last five prints I ran with the filaments (not Bambu ones—I want to use up my stockpile before buying more of theirs). I’ll be leaving town today, but once I’m back, I’ll run the auto calibration and update you! Thanks! I’m quite new to Bambu, but I’ve been a long-term 3D printer user, so maybe I was winging it too much.
Could the filament be the problem? Is it too wet?
Would that only cause problem with bigger print areas?
First layer is perfect, bu then it starts, its Giant Arm PETG btw.
Based on the images shared, it seems like the print speed is too high or the volumetric speed is more than the filament can do. It works with the 3D Benchy because the print speed is not as high on a smaller object compared to a model which has long print moves.
This means that more filament passes through the hotend when printing larger models, and if the filament cannot melt fast enough, it can lead to issues similar to the one reported, where the printed layers are inconsistent or interrupted.
It is recommended to first make sure the correct filament profile is used. If you are using Generic filament, ensure the appropriate filament profile is selected.
Next, you can try to lower the filament volumetric speed with 1-2mm3/s from the default one.
You can also try to set the hotend temperature 5-10C higher, and/or use a lower layer height such as 0.16mm which should help you get a better result.
That looks like over-extrusion to me. If auto-calibration doesn’t help, I would try manual calibration and at least try the flow dynamics and flow rate without fine calibration.
If, for example, the best flow rate result determined for your material is 0.92, then it might be advisable to go down in tiny steps by 0.02 to 0.04 in the direction of under-extrusion. Or, which also works very well for me - I take the second-best value in the under-extrusion range and add 50% of the difference to the best value.
You are offered the values after the test, you have to click on -5 or -10, the value is calculated and entered in the surface. Make a note of the values and go just below or above them as required.
And I also use black PETG from GIANTARM, here are my filament settings:
Flow: 0.95
First Layer: 235°C
Other Layers: 235°C
Hi
Thank you for your input, I’ll def try your settings first, maybe they’ll work for me.
I manually calibrated both the flow rate and fine adjustments, but the pictures I sent were taken afterward. I’ll redo the calibrations based on your feedback and focus more on under-extrusion, if your settings don’t work.
Attached is a picture of the same print done with PLA. I wanted to ensure that the issue is with the material, not the printer, and it looks pristine so far (stopped at the same stage as the PETG print)
That looks really good so far.
In my experience, every filament is different - especially in the cheaper price ranges. I therefore take the trouble to calibrate every new non-Bambu Lab filament. This takes about an hour all in all, but then it works.
And I always prefer to go minimally(!) in the direction of under-extrusion.
Another try with adjusted settings, I guees this material is just not suited for big prints at a decent speed, maybe with 60mm/sec all the way, but that would take days.
In the penultimate picture, however, I have the impression that you are already clearly under-extruding. I would quickly add another 0.1 or 0.2 in the flow, try it out and possibly - if not yet sufficient - add another 0.1.
And the layer adhesion is probably failing in some places. I assume the plate has been cleaned with isopropanol and then wiped with a little water and washing-up liquid?
Update:
I switched back to the “Generic PETG” setting from Bambulabs, and it works well for smaller objects (dehumidifier for the AMS)
The temp with this setting is way higher than the recommended settings from the producer, but it seems to work better.
Back to the Problem:
Here is the page with the settings, including the cooling page for completeness, though I haven’t made any changes there.
The test prints using esun-PLA Matte Grey at a smaller scale worked perfectly, but issues began when we upscaled and switched to Giant Arm - PETG Black.
It is recommended to keep the temperatures set in the default Generic profile.
Mostly because the recommended temperatures for filaments are usually for printing slower.
For PETG, 255C - 260C is OK for the speeds in the profile.
The Generic filament profiles are configured to account for the higher print speed and the filament melting requirements.
These settings should give you much better results.
Sorry I did not get back to you sooner. Had some tractor problems here. I have read through the replies and it all sounds great. One more thing I would is open the door and the top should be about half cracked. I have ran some test parts here with Sunlu Filament whit the setting provided in this post and it seemed to have came out pretty well with a large disc approximately the size that I see you have here. I ran into a lot of beading prior to opening the cabinet you can give this a try and see how it works period
I am sorry, but the settings you suggested are performing worse than the original “Generic - PETG”, used it as a base and put in your numbers.
Picture: Left is the “Generic - PETG” and right is the same model with your settings.
