Invitation: The PETG sphere challenge
Dear Prusa Users!
I like to invite you to the Sphere-Challenge!
A Sphere is the single 3D-Object where no cheating is possible. So I decided to take a Sphere with 2cm diameter as my goal.
I am using PETG as my daily work material, with no flaws and perfect prints. I can also print with PLA via MMU2s in several colors without problems.
My Original Idea was to print with a solutable Material PVA+ as supports utilizing the MMU2s-Extension.
But this failed badly. The PVA+ is brittle but mixed with PETG it becomes a beast. The cleaning volume starts becomeing cluttered after the second filamament change. I am not the first to report this here.
I read about using PLA as support for PETG and I tried with good success. But the PLA contaminated the PETG. This may be solved by a larger cleaning volume.
This image is bottom up after scratching off the first layers. Looking closely you may notice the green tint of the first 20 layers, caused by the contamination with the green PLA.
Also the irregularities of the first 10 or so layers are obvious. This may be solved by fine tuning the support-parameters.
Can you come up with a perfect PETG sphere? Please join the challenge!
Cheers,
Volker
RE: Invitation: The PETG sphere challenge
Happy printing!
2x Personal MK3IR-BMG09 (Full) BEAR + MMU3 mod., ...
RE: Invitation: The PETG sphere challenge
@holger-s3
Realy cool, what is the making of? Am I right that I spot also some (whitisch) contamination in the lowest 20 layers?
Cheers,
Volker
RE: Invitation: The PETG sphere challenge
It is made of PETG, ASA, PLA, ABS whatever you want.
The sphere is freely scalable and does not require any supports.
Have you already looked at the attached stl file? Further questions would be unnecessary.
And no, it's not a contamination but just a reflection of light.
2x Personal MK3IR-BMG09 (Full) BEAR + MMU3 mod., ...
RE: Invitation: The PETG sphere challenge
@holger-s3
That's cheating 🙂
Often linked posts:
Going small with MMU2
Real Multi Material
My prints on Instagram
RE: Invitation: The PETG sphere challenge
I think that's innovative 😀 .
A good way to success.
2x Personal MK3IR-BMG09 (Full) BEAR + MMU3 mod., ...
RE: Invitation: The PETG sphere challenge
@holger-s3
It is innovative cheating 🙂
But I am more interested in how to do it with supports.
RE: Invitation: The PETG sphere challenge
@volker-jaenisch
Change the contact distance to 0 mm and increase the purge volume. You should get a pretty clean and nice bottom.
Often linked posts:
Going small with MMU2
Real Multi Material
My prints on Instagram
RE: Invitation: The PETG sphere challenge
@nikolai-r
Did what you proposed (Contact distance to zero)
This is the outcome. OK but not really perfect,
I there a simple way to expose your slic3r settings here?
I had the most trouble to get the first layers correct. Switched to :
Print-Oulines first. That did the trick that my first (really small) layer was printed correctly. Also impure filament seem to be a big issue.
All the supported layers seem to have some bias in it. Also the density of the surface is imperfect. After the supported layers were printed the sphere is nearly ideal.
Any help appreciated
Volker
RE: Invitation: The PETG sphere challenge
@volker-jaenisch
This is already a pretty good result. My printers are busy right now, so I haven't printed this test. There are no magic settings :). It's always try and repeat with different settings which are usually valid only for the specific case.
In general you can adjust the support structure to better fit the sphere. You can also play with better cooling. But don't expect any wanders. This is still FDM.
One more idea. Create a negative bottom object. This way you should have a "perfect" support and the two objects should be able to separate with a little force (screw along the layer, not pull against the layers).
Often linked posts:
Going small with MMU2
Real Multi Material
My prints on Instagram
RE: Invitation: The PETG sphere challenge
@nikolai-r
Create a negative bottom object.
That's a really cool idea! Will try.
RE: Invitation: The PETG sphere challenge
Does not work. The sphere cracked at the top of the "negative bottom object" while trying to remove it. I not even used any force.
RE: Invitation: The PETG sphere challenge
@volker-jaenisch
You need to increase the purge volume. Here is my try with 140 and with more dense support. As you can see it's still not enough. I would go 200.
Often linked posts:
Going small with MMU2
Real Multi Material
My prints on Instagram
RE: Invitation: The PETG sphere challenge
@nikolai-r
Thank you so much for your support. The Contamination is IMHO really an issue.
How dense did you go with the supports?
RE: Invitation: The PETG sphere challenge
Hello,
Any tips to get rid of the first layers that looks bad due to overhang ?
Thx