Trouble with the overhangs for the impeller

[RebelDesigner]

Hi, Printing with PLA on an A1 and the impeller is just really hard to print for me. Used the Bambu 3mf files and speeds. This is my second attempt now with lower speeds. Thinking of printing this also with even lower speeds on the overhangs (now the defaults for slowing down during overhangs). Did anyone else have such a hard time printing this?

[Makerr-Studio]

I made a short about that topic; https://m.youtube.com/shorts/qC6KJh5NBew

I printed the first one in januari when the room temperature was colder. Now I needed to print with the door open en top cover removed. The normal impeller printed fine on my X1 carbon. It was the mirrored impeller that caused issues.

while the A1 has no covers you can try to blow cool air on the part while printing. I noticed that the side where the X1c has part cooling, the impeller was very smooth and the side that was not cooled was a bit the same as yours also when I clockwise printed it. Using the OrcaSlicer and clockwise printing with door end cover removed solved it in my case.

I printed out of PLA Matt. Hope this tips wil help!

[RebelDesigner]

I started to suspect room temperature as well. The printer was in a closed off room all night and the graph of an external temperature sensor is pretty much in line with the ugly overhangs. At a certain point the temperature starts to drop and the overhangs gradually start to look better.

I will wait a few days until the temperature starts to drop here so I hope it results in a better print! Thanks!

[RebelDesigner]

I cannot get the impeller to print correctly. Have tried everything. Printing when the ambient temperature was lower, and even an airconditioned room at 18 degrees. Slowing down to 50% printing speed on the A1 also does not improve to a perfect result.

Any tips I can try?

[phillipsnick]

Have you dried the filament?

[RebelDesigner]

I have not. It was a new spool straight from the vacuum packaging.

[phillipsnick]

I've found with some models even using a brand new spool, the filament still needs drying out for a few hours!

[RebelDesigner]

I bought a dryer and dried it. Indeed, also with a new spool this time, the result is much better. It’s not perfect yet. The front side is now smooth, yet the back (so the actual overhang) is still a bit of a moon landscape. I think next I’m going to install the prusa slicer and see if I can get a decent quality print of the mirrored impeller. Maybe the slicer also makes a difference.

Btw I printed with overhang speed of 30mm/s. That seems to give the best results.

[asucks]

What quality settings are you using in Bambu Slicer? I would recommend switching the print order to "outer/inner" if you haven't already. This will fix a lot of those issues.

You can also mess around with "Arachne" wall generator settings, as that can usually improve more detailed overhangs/curves in the slicer.

I would continue to slow down as well.

[Makerr-Studio]

Did you try the OrcaSlicer and clockwise printing already?

[RebelDesigner]

I have been printing other stuff yesterday so I haven’t had time to play with OrcaSlicer yet. I will try tonight.

Thanks for the tips regarding the order of walls. I will also do a test print with that setting later.

[RebelDesigner]

Tried switching the order of walls as well as the Arachne wall generator. Unfortunately no real improvements.

I have one pretty decent print (slowing down the overhangs to 30mm/s, but slowing down the entire print to 50%) where only the overhanging side of the fins are a bit like sandpaper, but the top side is looking OK. I’m going to sand that back side a bit and call it good. Next up today will be the Orca Slicer for the mirrored impeller.

I think in general this design can only be printed on the really high end machines. An A1 is just not good enough. Not sure if the design can be changed for easier printing without changing its characteristics.

[Makerr-Studio]

If you still can’t get the impeller smooth I can print them for you. I believe you live in the Netherlands so sipping will not be a problem. Are you making the EU version?

[RebelDesigner]

That is nice of you to offer! I do live in NL (Breda area), so I might take you up on your offer. Thank you.

I tried the Prusa Slicer with the mirrored impeller and the direction reversed. Had to stop the print after two hours because the quality was really bad again. Looking at the design though, is there a reason for the fins to be about 1mm thick on the bottom while being almost 3mm thick on the top? Making the fins thicker might help with stability while printing?

[Stevenpolak]

@RebelDesigner do you have problems with both orientations of the impellor? You could also print two of the non-mirrored versions. The mirroring is not functional, only for the looks :-)

[Makerr-Studio]

I did not designed the impellor blades myself. It is a 1:1 copy from the original file from pilson guitars. So a lot of people did print it this way. I only made the mirrored version of it 😅.

[RebelDesigner]

@Stevenpolak both versions. Up until yesterday I only tried printing the non-mirrored version. Both have problems.

@Makerr-Studio if the offer still stands to print them for me I would like to take you up on that! Let me know what the best way is to get in touch.

Still find it weird that I am having such a hard time printing this. I must be doing something wrong. Or the A1 is just not capable of printing such a difficult part.

[Makerr-Studio]

Yes it still stand. You can contact me on info@capturingdust.com.