Can you model this part? "Impossible" modeling challenge!

alnis

We've all seen those drawings of "impossible" parts. However, some of them can be modeled in solid modeling packages like Onshape...


Can you model this part?

sebastian_glanzner

Ahh, my brain hurts... 

alnis

Alright, I'm sure there must be a better way, but here's what I came up with for how I modeled it (view angle is dimetric for the effect):
https://cad.onshape.com/documents/8ca31f7738a79a85b95a3255/v/ec01ae9a2f35c9f598819fe6/e/8c20d3b8b0f90697c0eab70e

bruce_williams

nicely done!  I was thinking to try it with curved 'legs' to make it more connected.  Did not know where to start with angles though.  I see in your doc you tried a few things.  What did you do to know the build angles?

dirk_van_der_vaart

This one is possible,
https://cad.onshape.com/documents/c8046cd731aab4d0ad79d77c/w/d4485ab0d8c635525c82879e/e/74d4ca48153c7fc43589e0b4

MichaelPascoe

@alnis_smidchens
This was too tempting! I couldn't get it as smooth as I was going for, but it worked. 

We should be able to have a more fluent model with some more thought and effort.

https://cad.onshape.com/documents/2893deca4fdcc126ce0f55b9/w/5376821763307cf82baac72d/e/e05856f326cb351a347ee43a

Ste_Wilson

My mind's melting just looking at these. Entertaining! 

alnis

bruce_williams said:

nicely done!  I was thinking to try it with curved 'legs' to make it more connected.  Did not know where to start with angles though.  I see in your doc you tried a few things.  What did you do to know the build angles?

@bruce_williams Thank you!! To be honest, it was a lot of trial and error. Figure out how to get faces to look continuous and flat while also getting the perspective just right was a bit more art than science. Maybe I'll revisit it sometime to get it looking even better. Sorry for the super delayed response! Just found this when cleaning out my inbox

@MichaelPascoe Awesome model! Much cleaner than mine.

@Ste_Wilson Happy to hear it!