# Knurling on a curved/angeled surface

I’ve been using Rhino for Mac for only a month or so, been through many (if not most) of the tutorials. I’m struggling with creating a knurled surface around three parts of a dial. I highlighted the surfaces that I want the knurling on. The video someone posted at one point on here explains it well to some I’m sure, but I’m new at this, so I need it broke down. If anyone can help, I’d greatly appreciate it. I’ve made one in SketchFab, but its a nightmare modeling with that because of the errors I get.

Glancing at the picture, I would learn how to make the very outside knurl first. You could have just extruded something straight, IF it weren’t for how it meets with the canted/angled knurl. So, you might look at the knurl as a series of shapes that are polar arrayed (copied) around a central point.

If you make one single knurl from surfaces. It can be made from an extruded curve or a triangle. You will have to make one extruded on an angle, upward.

Then you can polar-array it.

The central knurl can either be made in the same way, or create a curve wireframe first, by making a single knurl(ett : ) and then extrude it upward. The curve can be made of a few curves, again polar arrayed.

The rest can be rotated from a curve profile. Add some holes, and you are out of there. Boolean subtraction would probably be how you’re going to have to make some of the outer holes because they aren’t normal to the surface, like the top central ones are.

Also, thinking destructively, you might be able to rotate a profile, and then boolean subtract shapes to get your knurling result.

First create two lines that define the knurl. Extrude these and orient to the surfaces that need to get the knurling applied. Use `ArrayPolar` to copy these around and then use `Trim` to trim all geometry to each other. The red, blue, and green surfaces will be consumed by the knurling and these can therefore just be deleted.

Also,
Here is a link to a previous topic on the subject.
Since the WIP for Mac also has Grasshopper included (Explicit History), you could try the following definition as well: