Rounded corners printed upside down
Hello
I need some advice. It's the first time I'm struggling so much.
Here is a model I want to print
I print it lying on its backside. The "raising" fillets are far far from what I would expect. They ends up irregular/damaged (some material strings printed in the air). I tried supports but it didn't help either.
Print without an Input Shaper looks a bit better but is still far from the model definition. In general, despite irregular print, the fillet is closer to the chamfer.
Just for reference, my MINI prints 3D benchy perfectly.
Is it possible to print such curves upside-down on MINI?
RE: Rounded corners printed upside down
Nope, not on any fdm printer really. Those are precisely how NOT to do a 3d print design. The bottom of the curve is a complete overhang, and as the gap between the bed is so small there isn't enough room to get supports and the z support gap under there, so supports cant help. By the time its high enough to fit support the angle has changed so that supports are less useful anyway. A Better design has the lower part as a 45 degree chamfer that then transitions to a fillet once the angle increases higher up.
Your print looks particularly bad so you might also have some other issues going on with cooling but that geometry just doesn't print well at that orientation full stop.
RE: Rounded corners printed upside down
If you support it with PLA or PETG depending on what your printing, with zero clearance you can do it. Model separate bodies in CAD that match the shape exactly.
I've done it with good success.
In this video you can see I did it with a sphere, not on the bed, but same concept.
https://youtube.com/shorts/87Sh4s_dzBU?si=HINxElRn_zA5ZDIn
In this video I didn't talk about it, bit you can see the white PLA supporting the radius of the wheel off the bed
https://youtube.com/shorts/41k47_w_-eE?si=1KfLlQ9rr1FduTwF
This is an easy task with the XL due to multiple print heads, but you could do it with a single extruder, you'd just need to do the filament changes manually with a virtual extruder.
RE: Rounded corners printed upside down
Nicely done.
RE: Rounded corners printed upside down
Totally agree, chamfer then transition to a fillet.
RE: Rounded corners printed upside down
Michal.
Possibly the filament is to hot or you have cooling issues, or filament not dry.
Hope this helps.
No, @neophyl is right. It looks like the op has followed a design for injection moulding. Whilst it could be printed with elaborate workarounds, as it's his own design, it's simplest to chamfer the corners.
Cheerio,
RE:
Thank you for your responses.
I print using PETG Prusament with default Prusament profiles. I cannot confirm or refuse arguments about temperature correctness. But I don't have other problems with printing, so I assume OP problems are specific to this particular case.
As mentioned the easiest way would be to replace fillets with chamfers. Another way is to get rid of slicky design leaving sharp corners. I have to admit that it would be the easiest solution. It's just a box for God's sake 🙂
But I hoped it can be achieved somehow. I'm going to look at Brian's videos too. Right now I succeeded in printing it upside-down, with a hollow space facing a print bed. Of course with extensive use of bridges. The result is great. But it requires a lot of additional material for bridges, takes twice the time, and... the box has an opposite part which is even deeper with some sizing-sensitive elements inside.
RE:
Of course with extensive use of bridges.
I meant supports of course
RE:
This is an easy task with the XL due to multiple print heads, but you could do it with a single extruder, you'd just need to do the filament changes manually with a virtual extruder.
I found, that I can use `Single Extruder Multi Material` Mode. I set each object to different extruder. Then objects are sliced with individual perimeters.
Unfortunately, I cannot separate them from each other. Is there anything more I should think of?
Thank you in advance
RE: Rounded corners printed upside down
If they are separate items in CAD then after you load it into Prusa slicer then there is a P button near the top of the screen that will break individual bodies into separate parts.
Is this what you were asking?
RE: Rounded corners printed upside down
Without it, it's impossible to assign different extruders to each object. So yes, I already did that separation.
RE: Rounded corners printed upside down
Ok, I'm not sure I understand what your trying to do. It's it possible to show in a picture?
RE:
Sure.
I found I was using Split to Objects, not Split to Parts. Should it give the same result considering that objects didn't move in relation to each other?
Here is what I do. Steps are described above each screenshot. Click on them to see full view:
I have the main object and its support prepared in OnShape:
I export them together to import into the slicer afterwards. I use Split to Objects to separate them. Since they lay down on the bed, this operation doesn't shift them to each other.
Then I set number of extruders to 2, enabling Single Extruder Multi Material feature.
It allows to set separate materials to the objects. Both stay PETG anyway.
Then I slice.
It looks like you are rediscovering the methods outlined in these threads although for a different purpose:
https://forum.prusa3d.com/forum/prusaslicer/manual-multicolor/
Cheerio,
RE: Rounded corners printed upside down
Yes what you've done is mostly correct, but you need to follow the directions listed in Diem's link so that you can change the filament manually.
I use split into parts vs. objects because they can be moved together on the print bed. Split into objects is more for wanting to print 2 separate parts and allows you to move them around separately. Either way would produce the same result of you don't move them. If you choose to use split into parts then you'll want to select interface shells under the multiple extruder tab so that it keeps solid shells between your parts.
You will not want both materials to be PETG as they will stick together an you will not be able to separate. You'll want your support material to be pla if you want your part to be PETG, or vice versa.
You'll want to make a profile for your pla using your Petg bed temperatures.
The only thing I'll warn is that without a tool changer this is going to be a lot of manual filament changes so it's probably modify your model so that it only supports the radius until it makes an approximately 45 degree angle rather than all the way to the top to save some filament changes. Plus it really doesn't support past that point anyways.
RE: Rounded corners printed upside down
Alternative option.... print it right-side-up, and support the underside.
No need for mixed material, the shown surface keeps good quality, and minimal scarring underneath due to flat supporting.