masonwheeler
Posts: 1
Joined: Sat Jun 09, 2018 5:21 pm

No support generated under model with non-flat bottom

I have a model for a helmet, which is not perfectly flat on the bottom. It arches upwards slightly, and this causes all sorts of trouble for attempting to print it. It seems that no matter what I do, I can't get support under the rim of the helmet, either automatic or manual, and attempting to print without it doesn't work because the distance is just too far and the printer ends up printing a bunch of spaghetti in the air.

Here's an image of what the slicer generates. This is a side view in orthographic projection.

Image

As you can see, there's a very small raft area at the very front of the model, where it touches the build plate, and nothing else anywhere. I'm just about at my wits' end here, because no matter what I do, I can't generate anything anywhere under the back of the model!

Can someone please explain what I'm doing wrong and how to fix this?
rrdavis
Posts: 421
Joined: Sat Dec 09, 2017 4:52 am

Re: No support generated under model with non-flat bottom

Try double-clicking on the part and decrease the Z-axis offset by 0.5mm or so.
RoboDLC
Posts: 134
Joined: Sun Apr 23, 2017 2:30 am

Re: No support generated under model with non-flat bottom

masonwheeler wrote: Sat Jun 09, 2018 5:41 pm I have a model for a helmet, which is not perfectly flat on the bottom. It arches upwards slightly, and this causes all sorts of trouble for attempting to print it. It seems that no matter what I do, I can't get support under the rim of the helmet, either automatic or manual, and attempting to print without it doesn't work because the distance is just too far and the printer ends up printing a bunch of spaghetti in the air.

Here's an image of what the slicer generates. This is a side view in orthographic projection.

Image

As you can see, there's a very small raft area at the very front of the model, where it touches the build plate, and nothing else anywhere. I'm just about at my wits' end here, because no matter what I do, I can't generate anything anywhere under the back of the model!

Can someone please explain what I'm doing wrong and how to fix this?
Rotate the model slightly to get more contact patch on the surface. This still may give you some grief. I don't like rafts myself, they are the last resort for me. I would manually add some supports under the arches, spaced every few mm, probably don't need a solid wall of them, but you might. If you have a bunch of support towers and you don't trust your printer, put a brim a few rows wide to anchor them to the bed.

DLC
D. Clark
Robotics and sensors engineer
And lots of other stuff for fun.
airscapes
Posts: 403
Joined: Tue Mar 06, 2018 10:35 am
Location: Philadelphia PA Area

Re: No support generated under model with non-flat bottom

double click the model and on the top section of the window that opens, increase the Z by 1mm and then add supports.. I do this all the time with tiny swords for D&D figures. Support won't generate if there is insufficient space between the bed and the model for the support.
If the part is small add at least 3 solid layers in support tab this way the support will stick to the bed..

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