conical hole from radius and apex angle

mark_nahabedian

I want to make a conical hole in a part.

I have a sketch plane perpendicular to the surface that will host the base of the cone.

I'm trying to define a right triangle to revolve to form the cone.

I have a line that defines the radius at the base of the cone.

I have a variable defining the cone's apex angle.

I can use trig to calculate the length of the other leg of the right triangle to form the altitude of the code.

I don't know how to tell OnShape that "the length of this line is the length of that line times the cotangent of the angle in that variable."

Suggestions?

Thanks.

eric_pesty

I'm confused...
Does the sketch in the example linked above not achieve what you are trying to do?

You could do it the "hard" way by using equations either in a variable or in a dimension box but I don't understand why you would need/want to do this... 

eric_pesty

Maybe I'm missing something but if you know the base diameter and the apex angle, the simplest would be to just sketch that and use a revolve.
Seems like you already have the sketch in the right plane too...

Something like this?
https://cad.onshape.com/documents/dfb1e7c565bf2c0c95a9f0f4/w/a4fe01b46eae8045848b9e9d/e/2dc9c753bd4bb51a2b9c3683

mark_nahabedian

I don't know how to tell OnShape the location of the apex.  I know how to calculate it, just not how to communicate that to OnShape.

eric_pesty

I'm confused...
Does the sketch in the example linked above not achieve what you are trying to do?

You could do it the "hard" way by using equations either in a variable or in a dimension box but I don't understand why you would need/want to do this... 

mark_nahabedian

Got it.  Thanks.  I forgot about angle dimensions.