I have my H2C now for a good week and I like the machine a lot. Except my bottom and top layer quality is worse than on my X1C.
The printer seems to be underextruding quite consistently. It’s visible on the bottom and top layer where you see some gaps between the extrusion lines and also some gaps between the walls and bottom/top surface.
This happens with Bambu Lab matte and basic PLA and the 0.4mm nozzle. I’ve tried different Bambu colors, dried them, but it stays. I’ve also tried some Esun with the generic profile and it also underextrudes the same as the Bambu Lab filament. I need to raise my flowrate about 3% on all profiles to make it perfect. But I would expect that the Bambu Lab profiles would be perfect just like on the X1C.
Other than that it prints nice, so I’m wondering if there is something wrong with the machine or if it’s just a firmware bug?
I have also tried ABS-GF, but there is hard to spot issues because of the glass fibers.
Here are some pictures of my issue. And it happens with other colors of the same Bambu filament as well.
Im having a very similar experience with my H2C, just like you said compared to my previous X1C something seems to be off with the default profiles. As of right now im unsure if its software related issues or something with my machine causing it.
I have also check all my PFTE lines and cut them to length so they optimal in terms of length and radius so nothing binds.
When I do a manual feed, I feel some slight resistance when going through the buffer, but it’s not that much. When I printing I see that the buffer is “filled” all the time, so there doesn’t seem to be any problem with binding.
I didn’t open the extruder yet since it’s a new machine and both nozzles experience the same issue.
I have been 3D printing for 6 years so I have some experience with trouble shooting and fixing/building machines. In my opinion this is a software problem since it’s very consistent.
The extruder is a servo motor. Maybe there’s some component variability that effects the servo’s PID loop and the extruder runs a little bit “slower” than it’s supposed to be running. That’d definitely be a software thing, calibration of the servo loop should compensate for component variability.
Try setting Flow Calibration to “ON” instead of “AUTO” and see if that makes a difference. The system should adjust the default flow rate up since it’s looking at the actual amount of filament coming out of the nozzle to decide what settings to use for Flow and PA.
That calibration only does pressure advance. Not flow rate. But I have it on anyway since it’s very close to my manual calibrations, so I stopped calibrating manually.
This is before a flow calibration. With a flow calibration I get it solved, but isn’t the point of buying Bambu filaments and a Bambu printer that their stock profiles are near perfect?
On my X1C I didn’t had to tune my flowrates with Bambu filament. I was spot on. Just a PA calibration and that was it. Now I need to increase every filament profile with 3% and then it’s fine. Which makes me think that something is off with either the firmware or the machine.
Good point @broodro0ster , I too would think that a BL profile printing on a BL printer with BL filament would be set up with this in mind. having said that, shrinkage is not accounted for and I should think that would be as well.
Yea, that’s true. I mean on the X1C is perfect (except for shrinkage) and on the A1 of my friend as well. It shouldn’t be any different for their high end machine.
I don’t have all the specs of all individual components of the H2 series, but I can imagine that tolerances on the extruder gear might influence the flow rate. But 3% flow rate difference would mean 3% difference in diameter of the extruder. That would be approximately 0.9mm on 30mm diameter. That is quite a lot.
But could be a poor filament batch unless it produces better results on the X1C with the same spool.
Ive had similar results with the same spools that made great looking results on my X1 with the standard profiles, so I dont think it has to do with filament batches
May I ask if you tried slowing down the print speeds at all, w/out adjusting flow ratio?
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My working theory is that the default speeds (and perhaps accel.) in H2 print profiles are generally too fast for good quality. H2 advertises 2x the max. speed for X1C, which looks good on paper and in slicer time estimates. The default profile speeds for basic filaments like PLA/PETG are way higher for H2. My prints come out consistently and significantly better when I slow them down. And I don’t think the printer is really built for those speeds… just from watching it, and as evidenced by people posting broken stepper motor shafts and destroyed lead screw parts and such… can’t be good.
Hi Max, yes I’ve tried that and it doesn’t help. I usually apply my own profile with a bit less acceleration and max speeds. I usually run 60/120 for out/inner walls, 200 for infill and 100 for the top layer.
If I need a big part with straight walls where I don’t need it to be very nice, I might run the default profile.
I opened a ticket yesterday to explain the issue. The answer I got was a screenshot of where you can increase the flowrate and they told me to raise the flow until it was good.
I know how to fine tune my stuff, but if every Bambu profile is about 3% off and the filaments work perfectly fine on my X1C, it’s not a matter of calibrating the filaments I think. I do this for 3rd party filaments, but usually it’s very close with the generic profiles. The PA calibration has more influence.
It seems this user had more or less the issues I’m having as well, except it was a H2D: H2D Poor Print Quality
What region and when did you get your H2C, im wondering if it is a small quality issue with a certain batch of the printer.
I got mine mid febuary shipped from their germany warehouse.
I ordered on the 2nd of March and received it the 6th of March. It was also shipped form the German warehouse.
I will do some more tests and report back. Like printing the default Benchy and some calibration tests with the 0.6mm nozzle.
Do you have some pictures of prints done with the default BBL profile and BBL filament and a big top layer? That’s where it’s the most visible.
I have also printed some figures for my son to test the multicolor capabilities and there it isn’t so obvious since there is no flat top layer on the organic shapes. But when watching from above, I see that solid infill also has small gaps and I also see gaps between the inner and outer wall. This shouldn’t be the case.
Yep, here are some of my print results, one of them is from the presliced file that came on the printer. The other 2 are printed from maker world showing both first and top layers that are flat being quite rough. I also have a support ticket going currently and am waiting for further instructions.
And then this one I printed sliced with the default profile on the right, and the left one is one with a slightly increased flow rate to see if upping it from the default 1 to 1.02 helped, but it looks like I would have to up it more still.
