Need help with threads and possibly how to use derivation to create them

ilana_kaye

I am a complete novice both with 3d printing and designing the parts I want to print.

I'm trying to make a cup with a threaded lid.  There will be a fabric disc placed in the bottom of the cup then the lid will screw on to hold the fabric in place. This is the link to my document:

https://cad.onshape.com/documents/f895d63c7d828c4de8145a48/w/040a34b0fc5223fa27564172/e/eb972a945e7e067bf8d726d5

antlu65  but I have absolutely no idea what I am doing or how to do it.  I can get the thread on the internal wall of the cup but not on the external face of the lid.

I would VERY much appreciate some help and also how to print them without supports.

MichaelPascoe

Looks like you have the right approach. Here, try this:
https://cad.onshape.com/documents/be52a50c955fe419850102fc/w/a69cb3d30a131...

Thread Lab is a good feature, I had to tweak some of the values to get it to work. Ideally, you would want 2 or 3 starts instead of one so you don't have to sit there spinning the lid forever, but I could only get 1 to work.

Boolean subtract with offset is an important step for tolerances so that the lid will fit. This is also tricky when offsetting helical and filleted faces.