How can I create a threaded nurbs object from a .stl of it

I really don’t understand why people only upload .stl meshes of models. I’m trying to create and accessory for my Dremel, and I thought I find other models with the correct threads that I could use to boolean the threads in my design. There are lots, including just a threaded piece for boolean, but it too is .stl. Is there some way to boolean a .stl mesh from a nurbs block?

In some situations you can turn each triangle mesh face into a surface and join into a closed polysurface.

When you say accessory for a Dremel… are you going to to 3D print it?

Probably.

Then why not forget about nurbs and subtract a mesh from a mesh?

I only know how to model in nurbs with Rhino. I realize I can model in nurbs, save as .stl and then add the threads by mesh boolean. I guess I just have bias against using faceted triangles to make curved objects. I’ll need to get over it.

you will likely need to run a tap thru the threads after printing anyways, so they just need to be accurate-ish.

grab a bolt with the correct thread from mcmaster carr and mesh it with decent density, then do a mesh Boolean subtract to get your threads, print, tap and you are good to go.

I do this all the time it works great.

In addition to the great McMaster method - (use that here on the regular) … there’s also a great plug-in on the PackageManager - BoltGen

… have been using it for a while, and only just recently realized in addition to the standard nuts and bolts it can also generate a “cutter” solid, which is slightly offset-ed appropriately to where in some cases no post-operations are needed

Yeah. McMaster-Carr is always my first stop, then GrabCAD. But neither had the m19-2 thread. (nor did FastenWorks) I did find this model, which is again .stl. https://www.printables.com/model/35010-m19-2-rotary-tool-thread

I’ll try it doing what I proposed above.