We received the H2D Combo with the AMS (not the laser edition) two days ago. So far, we have been unable to get good quality prints. It appears to be consistently under extruding, especially on the top layers.
We are using the latest version of Bambu Studio, as of yesterday (version 2.02).
We have tried the following troubleshooting steps:
Checked both AMS units on each hot-end (the PTFE tubes are routed carefully. We do not believe it is a result of feeding issues from either AMS.)
Ran the complete list of printer calibration options twice.
Tried both Bambu and Polymaker PLA.
Ran the Flow Dynamics and Flow Rate calibrations on the filaments.
Slowing down print speeds by about half.
Tried turning Ironing on and off
We also send one of our test print files to our X1C which printed it perfectly
Filament dried to under 10%
After running flow dynamics and flow rate calibrations, we manged to get one single print of a basic rectangle to look okay. Just once. Ever since then it’s been under extruding again.
We’ve looked through the forums, Reddit, and searched the Internet but haven’t found many people having this much of an issue with under extrusion yet.
We are wondering if we got a lemon of a printer, or maybe there is something else we need to try. We’ve submitted a ticket to Bambu Lab support, but reading online it sounds like they’re really slow to respond right now. Do you have any ideas on what else we should try?
Please see the photos. I am having this issue even with the prints from the machine This is how they have printed the whole time reguardless of settings or calibration.
Make sure everything is back to default, and print another benchy (Bambu PLA is ideal but Polymaker is fine). Once you have that let us know or share a pic of how it printed. I’m wondering if things have been lost in the corrections to fix the problem. Basically, the fixes are stacked on too high and could now be creating more problems.
Mine fell out he box printing pretty well. No calibrations (other than the first start sequence), no special settings. Printing mostly Elegoo Rapid and Bambu Matte PLA.
If yours is still doing odd things after its back to box stock settings, its possible one of the PTFE tubes (or both) are causing a drag on the filament. This will lead to under extrusion. Not a bad idea to do a test print from both filament paths (Left and Right nozzle using the same source). Something small short and quick. Maybe a thin rectangle from Bambu Studio’s basic shapes.
If you can’t find anything in the PTFE path, try a simple test print (something small and quick like a 2mm tall rectangle) and do one with the Flow Dynamics set to “Off” and one with it set to “On”. Let us know how that worked. This should force the system to set a new value for its calibration. This should only work for the pressure advance, but the marketing suggests its for “Flow Dynamics” as a whole so maybe it will also set a new value for the basic flow.
Finally, if everything is still doing weird things, tell us what is showing for the flow rate. Maybe it is as simple as a miss-key or automatically saved value that is way off.
I had problems with ams and extrusion too caused by short tube connections. I used extended tubes and care radius of tube connection not too small. Now it is working fine.
I have tried printing from both heads from the same source with no change in print quality. Flow dynamics also did not help. The K value I got with calibration is .033. I have done the factory reset on the printer and used the benchy that comes with it again. It seems even worse.
Unfortunately I’m also having print quality issues with the H2d. There is pretty obvious Z layer shift for some layers. Using the same filament and same print I’m able to get much better prints on p1s.
Good point, but I can’t say. Everything is too new, and I’ve never seen it make a suggestion of drag on the filament I had with tangles (it just recognized the full stop even though the tangle caused a slowing first). I would think it’s possible, but I’d rather not cross things off the list without knowing.
The 0.033 seems like an odd figure for Bambu PLA (not sure about Polymaker). But I don’t think that is a big enough variance for the problem. I was more curious to see what the filament’s “Flow Rate” is set to in the filament profile. Do you know where to find that? If you have a setting problem it’s likely that.
For the Benchy, if this is the 20 min Benchy, I don’t think this is far from normal. I think it is a little worse than the out of box experience, but only by a little. But if that is the 40 mins user sliced Benchy, that would be significantly worse than expected. I’m assuming you are saying this is printed directly from the printer with the pre-sliced file (20 mins). I can’t run the pre-sliced file to compare (doesn’t work if you have the High Flow nozzle setup) but when I look at other people’s prints, yours is only marginally worse. However, it is only worse in the flow rate area, mostly confirmed from the bottom (shouldn’t have gaps on the first layer).
Here are a couple of fast benchys from other sources
hmm. I see a flow ratio of .98 but no mention of a flow rate in the settings if I go in to edit them.The fugly one is the 20 minute benchy that comes preinstalled on the printer. I will try with one from the website thats not a speedy benchy.
Sorry, “Flow Ratio” is the correct terminology. And 0.98 is a good normal figure. So, it leads me to think the problem maybe physical (check that there is no drag or tension on the filament). If no drag is present, consider doing a cold pull or just a good poking with the included needle to check for a partial clog (both nozzles). If you want to throw a patch on the problem, try a Flow Ratio of 1.03 and see if it improves.
Sorry to be noob about it all. What is the best way to check for filament drag?
I did a cold pull on both nozzles per the wiki yesterday and there was no change
I would pull the PTFE tubes out of the tool head and just slip the filament in to the two paths (one at a time) and check if it feels draggy. Ideally, it should move very freely.
One thing that may help run a high precision nozzle offset calibration.
A YouTuber just released a video showing it working on his badly shipped/damaged machine.
Don’t know if it’ll work for you or not but if it helped with that machine that was even damaged during shipping it may help yours.
This is how they have printed the whole time reguardless of settings or calibration.
