Creating Zig-Zag pattern split on cylinder

ricardo_romo_ramirez

Hi, I'm trying to recreate an stl, and one of the things I'm trying is to split a cylinder using a zig-zag pattern like this through the cylinder Y Axis.

Here's the doc: https://cad.onshape.com/documents/1671297e6cd1347a60024bb9/w/8056e634dd18d6b45ac4967c/e/2744bcd8ea374c73df758837

I tried creating a tangent plane from the cylinder and doing a split, but it would not take the sketch as the tool. Also tried wrapping, but split would still not work.

Any suggestions on how could I accomplish something like this?

jelte_steur814

The key is to really understand the geometry precisely and it'll tell you how to model it.

see how all lines are converging in the middle to the centre, so probably it'll be revolved/circular patterned.

and even the tops of the cams seem to go down. likely they end up in a single point on the centre axis.
top of the cam on the outside diameter is precisely 2 mm. let's draw that triangle in a sketch.

so the half a cam geometry can be modeled with a revolve of 360deg/(18cams*2(for the mirror) of said triangle.
and then use a 3pt plane for the slanted angle. mirror, circular pattern and done.

https://cad.onshape.com/documents/c4b40c3056e6e5884149bb2c/w/ad468cb3accf4be8479714ca/e/1193fca6b454f676fe92d920?renderMode=0&uiState=67d013fe7de7723b8e29e926

GregBrown

A Hirth joint is a fun parametric model to play around with. Here is an example with a few variables to drive it.

The number of teeth will be calculated based on the other dims…

https://cad.onshape.com/documents/b9a7c1439c00e391f738dc97/w/462ec153ed8873c5c5d11699/e/4eb1461d1d07fa8ec3044ef7

ricardo_romo_ramirez

Thank you guys! these are great!