Cut and reassemble large cup holders

So, to help with printing and keeping the supports down, I’d like to cut this about 70/30 (30 being the top half with the lip). What would you guy suggest the best way to cut it and reassemble it? This fits down into a space very similar in size so I can have to big of connecting point but the have to support the 2 40oz bottles of water and the bouncing of travel in the car. I’m sure I’ll super glue it but need so mechanical connection too. What are your thoughts? This is really my first design so I don’t have much experience. ThanksCupHolder1.1.skp (1.7 MB)

Here are some ideas. First off I am going to assume you know that your cup holder top is not flat or symmetrical.

Second, I see that this model is at real world printing size. It is strongly recommend that you scale up for working on geometry this small as SketchUp can have problems with the tiny faces that result from making curves at this scale. Common practice is to model everything for 3d printing in meters and treat them as mm. When you export for printing the .stl file has no units so you can set your slicer to import as mm. This will avoid many problems associated with very small geometry.

I have outlined a simple method of splitting the object that retains it’s solid status by making a second version and positioning two cutting boxes relative to each-other with the z planes aligned to cut in the same location. I then used solid tools>subtract to trim each of the cup holders in the opposite direction (this operation takes a few second, be patient).

I then used the offset tool to divide the top face of the bottom piece insetting it 1mm, and push-pulled the outer wall down 3mm. I did the same to the bottom face of the upper piece. This makes an overlapping lip that does not change the overall height. These walls are pretty thin to begin with at around 2mm (they are not exact) If you could make them thicker it would be a stronger unit and easier to make a joint in.


Thanks for the info. That’s correct, the top it built to follow the stupid curves of the center console in the car. What a pain! Anyway, this is exactly what I was looking for. There are so many tips and tricks that I have yet to learn. As a follow-up to your suggestion about the wall size… I agree, it is a bit thin. At this point though I have put a lot of time into it and would want to start over. With it built to this point would there be a easy way to increase the wall size without messing up the top lip? I want to keep the inner diameter the same so I’d need to increase the out diameter.
Thanks again.

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In that case, well done you! It looks like a tricky organic shape to get right. Incidentally, I would go into model info>units and uncheck enable length snapping, it can introduce errors, search the forum to learn more.

At this point with all the exploded geometry connected it can be difficult to make adjustments. It’s always good to make lots of incremental saves of every step so it’s easier to go back and modify individual components. Was thinking about maybe Joint Push Pull for this but I could not get it to interpret correctly and I have to go see about dinner.

I did manage to thicken the walls while keeping the same ID in a down and dirty way by selecting the outer surface (make sure hidden geometry is off so you can select the entire surface as one). Then scale that surface around it’s center (hold modifier key control on Windows I think to scale around center). Do it in X and Y direction to a scale factor of 1.02 , this yielded a wall thickness of 3mm without effecting the height. This does tweak some of the connected surfaces but is perhaps still serviceable, you could try bigger scale factors fo a thicker wall, but the distortion will be bigger also. Not the cleanest but it is still a solid.

Could probably come up with something better, I’ll give it a think or perhaps someone else will pop by with a good idea. Off to dinner…

Cool, I’ll play around with it. Thanks agian!

Something to keep in mind, you can always group the parts you don’t want to modify.