Hi,
This is a lid for a box I am going to 3D print. It was created in Rhino 8 by a boolean difference from the physical case it sits on. If I print this as is, I’m concerned it won’t fit, and I think I need an interference fit. I would like to know the best way to scale just the male part of the lid so it will fit snugly?
Thanks
Board_Case_Lid.3dm (238.3 KB)
I have not looked at your file.
Instead of offsetting a part, you could also model the gap and subtract it from your part. The amount needed depends on your printer and needs to be tested. I’d start with a gap of 0.2 mm
Hi @user1886
I’d just use Inset in the bottom surface and inset the border 0.2mm (as @martinsiegrist suggests) and then use PushPull to move the smaller face to the level of the “original” underside of the lid - see video
wonderful application of those two tools-
Thanks for taking the time to help, it’s appreciated. I’m not sure how the push-pull command works in your example. How did you select multiple faces? I get something like this when I try in Rhino 8.
Hi @user1886
I think you just need to zoom in a little closer, so it’s easier to select just the tiny, outer surface 
-Jakob
For your information, it worked perfectly. I verified it dimensionally; I just don’t know how I did it. The corner sort of presents an optical illusion, too. So I’m selecting the space the inset created, as in between the two lines? If so, nothing happens visually. The next step is confusing me. Assuming you have endpoint snap enabled, what am I snapping to? Multiple points or just one? BTW, what screen capture program are you using to generate the video? I used to use Snagit but that was 15 years ago.
Hi @user1886
Yes, the Inset command works by offsetting the edge curve inwards and split the surface along the offset - so now the narrow edge and the larger center of the surface are two separate (but still joined) surfaces. PushPull works on surfaces, so what you are selecting is the newly created narrow surface, that you can move up/down along its normal.
Exactly! In this case it’s the End snap, and I’m snapping to the original corner at the underside of the upper part. It can be a little hard to see that any material was removed, as the inset is so small. Also, the PushPull command runs its own, internal version of MergeAllCoplanarFaces, so that the new underside of the upper lid shows no sign of the material that was removed.
Here’s a video of the same commands, but done slower and bigger dimensions, so hopefully it’s easier to see what’s going in 
I realize that the original was a little hard to follow 
PS I use OBS Studio for screen recording - it’s free. The interface can be a little daunting at first, since it has options for both streaming and recording. I’ve just made a few presets that work for my simple needs, and hardly ever touch the settings anymore. If you’re on Win11, the build-in screen grabber (Alt+Shift+S) does both stills and videos, and is VERY easy to use!
Very clear now. Thanks for making another video showing the process. I’ve 3D printed the cases for a control board and power supply, and they fit perfectly. Very cool command. I’m on Win10 still and will check out OBS Studio. I can’t be any more complicated than Blender.
True!
