How to cut a larger piece for 3D printing?

w_s856

I am building an Anti Cat Laptop Protector ™ - a kind of cover I can put on my laptop so that the cat can lay on it because I give up hushing her away and see her coming back the minute I turn my head. This marvel is here: https://cad.onshape.com/documents/af32f32f98d639c630f49c60/w/fc75177a89a9bf4f6f8a805d/e/46c253d1b35abd4974a01050?renderMode=0&uiState=673a46b6ed47e06cbbc6aa59

It is too big to be printed in my small 3D printer so I need to cut it in four and glue (?) it afterward. I have two questions:

• question relevant to Oneshape: how can I cut a part into four parts?
• question not relevant to Onshape but since we are there and there are knowledgeable people around: what would you say is the best cut to do to make it? The cat weights 9kg and the print will be PLA so I put a continuous ridge at the bottom to support the weight

EvanReese

The Split feature can make it into 4 parts. I'd consider adding some kind of interlocking system to the joints to force it to line up and add strength there. Or get fancy and laser cut the top out of aluminum on sendcutsend.com (or something) and attach 3D printed parts to that, probably with screws.

robert_scott_jr_

Along with Evan's advice, once you have modeled an interlocking method (I use dovetails) I suggest you model smaller parts using whatever interlock you've decided on to discover how you will probably need to 'tweak' the joints to ensure the joint will actually mate properly. From experience, I've found that a filament printer (at least the one I used) cannot attain the precision required needed to allow the joint to succeed. - Scotty

_anton

Yeah, parts like this are challenging because everything is flat. Even if you fasten the parts together, the connection will be weak and even a bit of leverage can cause it to snap. I think you'd want lots of contact; I second the dovetails. You can print smaller test pieces to get a good clearance (0.2-0.4mm is a good place to start). Maybe you'd want to also glue on a backing plate of stiff cardboard or something?

For printing, you shouldn't need anything special. 2-3 perimeters, 20-40% infill, and 2-3 top/bottom layers should suffice.

MDesign

https://forum.onshape.com/discussion/25887/how-to-cut-a-larger-piece-for-3d-printing

maybe if you build it with an uncomfortable surface you won't need to worry about the strength of it…🤣

w_s856

https://forum.onshape.com/discussion/comment/109705#Comment_109705

I think you do not realize:

• how the family cat is determined to sleep on the laptop
• that, should my family find out that I am torturing the cat, the contraption would fly through the window presto and I would need to apologize to the cat and promise to never do that again. With witnesses.

MDesign

LOL. Torture was not what I had in mind.

w_s856

https://forum.onshape.com/discussion/comment/110384#Comment_110384

Obstructing whatever for the cat in the house is seen as torture by my family. She has to have access to everything and the best spots to sleep on.