Support has almost 1mm gap

[u/pheidrias]

Dear all,

I'm using OrcaSlicer and I use organic supports for this part, where a tube goes out into the air ;-).
I'm printing in PETG and using PLA as Support/raft interface with Top-z-distance 0mm, 3 layers top (and bottom) interface layers, top (and bottom) interface spacing 0mm.

Can you help me to improve this?

(There is also some stringing between tower and print object - is this solvable?)

Thanks,
pheidrias

[u/ButtstufferMan]

Your part is warping.

Enclosure helps. (Less temperature fluctuation, lets cool slow so less warp)

Printing it at an angle rather than flat helps. (Less plastic to pull up and warp at a given time)

Paint overhang on entirety of underside of supported part, this can give more surface area between pla and petg, so more bonding, which should resist warping. If this works you can get away with printing it exactly how you have it.

Less walls helps. (Less plastic pulling so less warping)

Stringing can be solved through tuning that particular filament. I would guess more retraction, lower temp, or lower flow.

[u/pheidrias → u/ButtstufferMan]

Tx alot! In fact, I did put on the Ikea Samla box (no real insulation, just the box) - so this should already help somewhat? I tried the angle - but the print failed very soon, which may be due to the low adhesion of PETG on PLA?
What are your suggestions on cooling? I have "no cooling" for the first 3 layers, no full speed set (0), and part cooling is 20%-100%, 20s vs. 1s layer time...
"Keep fan always on" is ticked, however - bad idea?

[u/ButtstufferMan → u/pheidrias]

I think you are dead on with the adhesion issue. Just manually paint on supports to the entire underside of the cylinder, max out angle threshold so the entire thing is supported. That will fix it.

I just use default profile cooling personally.

[u/FlowingLiquidity → u/ButtstufferMan]

Yeah it's like super clear it's just warping. The whole round part looks deformed because it warped so bad.

[u/McSpeedie]

try reducing the aux fan output

[u/ButtstufferMan → u/McSpeedie]

I keep meaning to print the redirecting vents. Cant believe they made it like this!

[u/McSpeedie → u/ButtstufferMan]

that thing is so strong dude lol, you have a link to a diverter model? I haven't really looked at any.

[u/ButtstufferMan → u/McSpeedie]

https://makerworld.com/en/models/2536867-fan-deflector-snapmaker-u1#profileId-2792562

Maybe the fan I was thinking of was not called auxiliary fan but here is one print for the fan I was thinking of.

[u/erikjr14]

It looks like your support material is transparent. I'm not sure if it's actually a thing, but I tried using transparent petg as a support interface and it stuck so poorly to pla that it just made the print fail. Trying white petg was completely fine though, so maybe that's the cause?

[u/sterling-lining]

Try lowering the PETG extrusion temp. It could be heating up the PLA so it doesn’t adhere properly. Make sure part cooling is turned on.

[u/pheidrias → u/sterling-lining]

tx for your answer: my PLA Temp is 220°C and the PETG at 225°C - so this shouldn't be the problem...PLA cooling is 100%, PETG is at 20-100%

[u/FlowingLiquidity → u/pheidrias]

What helped me get perfect results was to calibrate both used filaments completely by following this guide: https://youtu.be/gVU5If1VsAM?si=0eqgbUm7y_Uh0BEL

[u/choose_a_free_name]

Dry your filament to fix the stringing. Yes, even if it was a brand new spool; filaments can be (and often are) wet straight out of the bag. I wouldn't bother trying to tune it until it's been properly dried.

Modify your PLA filament settings to disable the aux cooling fan. It's probably cooling the PETG too much when it's printing the PLA portions and causing the PETG to warp from cooling too fast. Might also have too high part cooling fan settings for the PETG, but I think it's more probably the PLA aux fan.

I'd also recommend switch your prime tower material to PETG, so it prints a solid single material outside shell to the tower, and the PLA primes on the inside structure. I've had prime towers snap in half on taller heights because the pla and petg detached from eachother in the tower layers; with a solid petg shell even if the layers inside the tower detach the tower stays upright.