Threaded Sheet Metal Lid

[Anonymous]

I am having difficulty modeling this certain part:

 

The base is easy, I can do it with a revolve. But I need to add threads to the interior, however it is not thick enough to just tap/turn a thread. As its sheet metal, the threads will be formed/bend/spun (whichever method you choose to make it), but I can't figure out the best way to model it. 

I have tried threading a solid piece using Fusion's thread feature and then taking offset surfaces. I have also tried nested coils, both of which leave me at sticky points I'm not sure how to work around. The exact specs of the thread, major/minor diameter, pitch, depth, etc. Those aren't too important right now as long as I have an idea of the workflow I need I can fill in those gaps later. 

Thanks, 
Ross

[jasonhomrighaus]

Ok I've looked at your model but I'm a little fuzzy as what you are trying to accomplish.  Could you describe the parts in your model and what they represent?  is one the "can" the lid threads onto?

I am also not sure i get the relationship between the Pictures and the models.

[Anonymous]

None of them are the cans the lid threads onto. They are two different methods I was playing with to model what I am looking for. Basically the final product will be the pictures, but the open edge will be "threaded". Really its just a mason jar or tin screw on lid, but because its sheet metal it doesn't have threads cut into them, rather the metal is formed.

I am effectively trying to model the lid as in the picture below, but with some different geometry. 

[Anonymous]

I played with the model and my vest outcome was to create a thread then thicken the surface of the thread as a new body. Then the hardest part is integrating the thread into the rest of the lid.

What is the goal of the modeling you are doing? Are you trying to make a forming die or something or just to visualize the look of the thing.

[Anonymous]

That's the part I got stuck at, incorporating the thread into the rest of the model. I am just trying to visualize the look of the part, as well as be able to communicate what I want to the shop that is going to make it for me. 

[jasonhomrighaus · Accepted solution]

Ok try this.  I thickened the thread off one of your other pieces so the size is probably wrong.  Next I created a shell of the same OD,  Used some Tangent construction planes to confirm the center, then I used the sheet to split off a little bit of the Thread so i had a flat planner ring on the top edge.  Next I quartered the shell and the thread  set the height of the shell so it was close to the thread then I lofted each quarter from thread to shell.

Once all lofts created i combined it all to one body and I think it makes a pretty close approximation of what you are after in this case a roughly .5mm thick round shell with molded threads of the same thickness.

let me know what you think.

[Anonymous]

Ah very cool! Thank you for the help.