Creating a sinusoidal cut on a cylinder

daniel_jacob753

Hi there, does anyone know how to make a sinusoidal cut on a cylinder?  First, I made a sketch using defined points and a spline to make a sine wave.

Then I wrapped this around the cylinder.  I was not able to directly cut at this point, so I wrapped as a surface.


Then I tried to cut this.  Created a section as shown here.  Constrained it to be parallel to the central axis.

Then I swept this.  None of the sweep options align with what I need.  If I keep the sketch oriented, I get this...

If I do not orient I get this...

I've been considering creating a second wrapped sinusoidal surface on the ID and then (hopefully) being able to get an accurate solid from a merge of the two.  That will be a good bit of work and not sure I'll get what I want, which is a cut that follows the sine wave on the outside and is perpendicular to the outer cylinder.

Thanks for any help

glen_dewsbury

Try this as a sample to get started. Note that I made the cylinder sketch as #diameter+0.001in to increase the circumference other wise I get an error if I let the curve wrap exactly fit the surface.
https://cad.onshape.com/documents/12d9fbf125e4090eb0e04195/w/c311b64852d9200433a8f7a2/e/6a93ef1aaa6d5e05b1d7f566

EvanReese

a sine wave wrapped around a cylinder once is just a straight line cut from the side forming an ellipse, no? Does it need to also update to waves with a frequency higher than 1?

daniel_jacob753

Thank you Glen!  REally appreciate the help.  Let me play with that a bit but I think this might work

glen_dewsbury

Evan_Reese said:

a sine wave wrapped around a cylinder once is just a straight line cut from the side forming an ellipse, no? Does it need to also update to waves with a frequency higher than 1?

@Evan_Reese
Yes. The advantage in my sample is from some comments here about cam profiles. May not always be a sine wave needed.