Thread

geppetto_sepp

Hi I've watched 20 videos on YouTube now and just can't figure out what I'm doing wrong.

I would like to cut an m4 thread in the two small holes.


I already prepared it but it doesn't work Maybe someone can please help me before I throw the lepptop against the wall


https://cad.onshape.com/documents/3a7bd672f9a537bb738c0993/w/d08749a9966bfffc816ceed5/e/439fc6e82d301451a95d7e0f

eric_pesty

I would recommend using the "Threalab" feature for this as it does all the hard work for you!

https://cad.onshape.com/documents/5c0528b62c1fbb13a2a0e739/v/0bb9d00523f327052c0a2e24/e/7cbb452d4d5e963a034ce616

As far as fixing the issue you were having, it usually helps to have the profile expand a bit on the "other side" of the sweep path. Extending the triangle a bit makes it work:

geppetto_sepp

Hello

Worked thanks  


Why do I have to extend the line?
Just for understanding

eric_pesty

I'm not 100% about the exact details but I think it's related to "approximations" in the math (rounding errors) that can cause edge of the triangle to not always cut all the way through (leaving very thin bits of material behind) when drawn exactly on the inside face of the hole.

It's a fairly common issue with 3D CAD like this so when something fails it's always a good thing to try (especially when working with "complicated" shapes like a helix).