So I just switched to the 0.6mm HF nozzles on my H2D here at work and I printed a quick ABS tool tray. I printed it with Bambu black ABS, 0.3mm layers, 15% gyroid infill with infill combination turned on.
I know the printer did the flow calibration before the print but it really doesn’t look good on the top surface at all. There’s noticeable gaps between the solid infill and the walls in places, especially around the text. Also the text itself looks terrible with what looks like under extrusion. But the yellow parts below the text look great.
Any idea what settings to tweak to make this better? TIA.
I don’t have the H2, but on the rest of bambu’s fleet, when you do a multicolor print, the flow DYNAMICS calibration [not rate] only occurs for the first filament in the file, so you may need to do the calibrations for at least yellow [do both imo], and save it to the settings.
You mentioned bambu black abs, what’s the yellow? Also bambu abs? If so, the same PA setting is likely good for both
To my eye, it looks like some combination of flow rate too low and pressure advance [flow dynamics] incorrect, or the speeds being used are too much for the filament.
I’ll give that a shot, I’ll also slow it down as it knows it’s got the HF nozzles installed but it also knows it’s not HF filament, so I’m not sure. The yellow is Polymaker but the only issue with that is in the text. The other pads of yellow are solid and great. It’s also the top layer of black that’s not meeting the walls it seems, mostly around the text, but I did see some areas in the top solid infill that look underextruded so I’ll just slow the top solid infill speed down.
I printed it again after I added a feature to the part, but made sure the flow dynamics calibration was set to “on” instead of “auto”. Again the yellow top solid is perfect, the text looks trash and the top solid black looks trash as well. I’m printing it again now but slower.
Well that didn’t work. I slowed it way down, added a third top solid layer and it’s the exact same - infill isn’t connecting to the walls only around the text and the rest of it looks under extruded, although not as bad as before.
Seen this behavior sometimes in a print on the intitial couple of top layers.
I have the feeling that your temperatures are a bit too high, Though they seem standard in the profile. Are you using Bambu ABS?
Personally I use minimally 5 top layers in a any print, and then this issue does not in my final layer.
I’m currently using 3 top layers. The black is Bambu ABS, the yellow is Polymaker PolyLite ABS. The yellow seems to be printing normally on the large top surfaces except for the text, whereas the black is printing perfectly everywhere except the top surface(s?) it seems. Printing slower did not help.
I haven’t had any issues until I switched to the 0.6mm Tungsten HF nozzles. My boss meant to order 0.6mm standard nozzles but got those by mistake lol. I’m sure they’ll come in handy though
Tungsten has a better heat conduction than hardened steel. You could try lowering the temperature 10C to see if it makes a difference. The shorter paths seem to be the problem, and those are running relatively slow due to acceleration/deceleration. You might try a small test piece to confirm.
An additional tip. Unless your part will be tortured a lot, PETG would be a perfect alternative for your ABS.
Try it with 0.4 nozzle.. at least I do have similar issues while using 0.6 nozzle (hardened steel no HF) on my P2S printing PLA too. The top surface with 0.6 nozzle is somehow inconsistent - same like yours.
Funny thing is, with 0.4 nozzle is everything fine and the print time is similar as it moves faster then with 0.6
The whole idea of switching to the 0.6 was to print faster. Being able to print thicker layers dropped the time on the prints it was bought for from 11.5 hours to 6.5 hours. It wasn’t needed for this specific print, I just didn’t feel like swapping them back out lol. It’s just a tool holder that’s going to sit in the toolbox drawer, no need for it to look perfect.
I get that, but at the same time, if you push your material past it’s limits, trying to reduce time will always reduce quality as well. It’s hard to determine from this side of the pixels if the material is choking or not. A simple flow rate test, only printing of the 0-chip might help see. What actual numbers are you using for max volumetric flow, inner/outer wall speed, top surface speed, and pressure advance?
