Trying to post pics. The first is the cupholder with the handle. I printed round for a proof of concept. Two issues. I cant figure out how to draw the handle onto the circle. If I could do this then pull the depth it will work.
The second happened during printing. Look inside and you’ll see a bit of a mess. It has to print that “floor” in mid air. It takes a while to stick to make it smooth.
You may need better-designed or better-positioned supports (if you tried to print this without activating supports, I’m astounded that it worked at all). You want just enough support to make the “midair” portion of the print behave as it’s supposed to. Too much support, and you’ll likely get rough surfaces where the supports and the printed piece were in contact. Too little support, and you get sagging and plastic spaghetti.
Luban’s support options are limited—you’ll get a wider range of them from a more advanced slicer such as Cura. Hand-positioned supports, if correctly done, will get the best results of all. In this case, I would guess that the optimum support system would involve a circle touching the bed at the unsupported edge of your cupholder design, then maybe another one halfway between that and the supported edge.
I designed something similar, and Cura’s concentric supports worked really well. Looking at the original photo, the bridging distance looks pretty good. They might only need a single concentric support, depending on how well the bridge lands on the support. But I’m sure Luban’s grid supports would be acceptable. There might be a little roughness were the inner circle extends over open air, but it’ll be a much smaller amount. Use the layer slider to see that layer, and see how much the print head travels out over unsupported air.
Regarding design, I haven’t done any Fusion360. I do most of my design in TinkerCad, using a series of positive and negative shapes. I’d make that handle inset part by copying your current cylinder, fiddling with the inner and outer radius to make the smaller circle, then cutting it in half. Then a series of rectangular solids to connect the sides and base. Then fuse all the objects together.
If you print it right side up, it will need the most supports, but where the supports attach and detach from will be hidden in use. So any blemishes they cause won’t be a problem.
Make sure “combing” is turned on in Cura and it will keep it from jumping across the open areas and reduce stringing.
Tinkercad works really well for doing the positive and negative trick. Even though I know how to use Fusion now I still use TC a lot when I want to do something quick. You can do the same thing in Fusion but it’s not quite as easy or user friendly.
