Hollow Model Fills In When Printed With Bronze Filament

I have a Lulzbot Mini and I am trying to use Colorfab Bronze filament to print a hollow hexagonal cylinder to use as a bead for a beaded necklace. My wife designed the model in Blender and exported it as an .stl file. It looks fine in Blender and in Cura. But when we try to print it, the cylinder fills in and it also prints a cap on both ends. We start with what looks like a perfect hollow hexagonal model and we end up with a solid hexagonal object. We uploaded both the Blender file and the .stl file if you want to look at them. We sure hope that someone can tell us what is going wrong. Thank you!
cylinder422.stl (1.84 KB)
cylinder422.blend (436 KB)

I had a short look at it on my mobile phone- is it possible that your model is very very small and you scale it up in cura?
In this case, cura thinks the small holes are defects in the model and it closes them on its own. The correct approach is to set the units in blender to mm,all stl files for 3d printing are supposed to be in mm!

Well, that part isn’t manifold, and it isn’t possible to 3d print it the way you have what is there at the moment. Right now you have the hexagon lid floating over nothing. You can’t print in mid air, you need to either have an angle out to that point, or support material under it. As it is right now that model will never print. It’s also not in milimeters. Almost all 3d printer softwares expect STL models sized for milimeters. You need to make a solid hexagon, and then extrude a hole down through the solid, not make it out of surface panels like that.

What size did you want the actual hexagon to be in MM? and how big should the holes be?

Thank you very much.

Well, I tried again. I really appreciate all the help. I made a different model in Blender, using the torus mesh instead of the cylinder. All I did was to resize it, save it in Blender, export it to Cura, and save it in mm in Cura. I couldn’t tell for sure if it was on the platform in Cura or slightly above it. Will this one work?
bead424.stl (56.3 KB)

It’s very tiny (12x12x18mm). If that’s what you want, it’s OK. But then you want to print at last 2 of this together to keep the available time for cooling high enough.

Well, yes and no. That model is maniforld, so it will technicallly print, but the point where you are attached to the bed is going to literally be one single loop of plastic holding the entire thing in place, so no, it will most likely not adhere to the bed. The more model surface area you can make stick to the bed, the better. If one end of the bead was flat, it would probably adhere well enough. Keep in mind it is difficult to print very small things in exotic fillaments like bronzefill as your first 3d printing projects. I would reccommend going to thingiverse.com download a couple things that interest you and print those just to see how the printer works before attempting your next bead designs.

One way to make that bead design work, would be extruding a flat cylendar onto the bed with the bead attached at a cut off point, and then manually cut it off after. Even with that, the transition edge would need to be about 2mm at a minimum.

Thanks to the help I got here, I got the idea to set the model on its side instead of on end. That provided enough contact between the model and the printer bed so that it could print without any support, and it came out perfect! You are right, it is very small. I will attach the .stl file. Thanks again!
bead424.stl (7.11 KB)