Mechanism connection for helical surface?

[mkeller]

Is there any way to make a Mechanism connection for a helical surface? I have two cams that twist when contacting each other due to helical surface geometry on each, but I cant make a cam connection between them. I also cant use 3d point connection because there isn't a round surface. Is there anyway to connect the two surfaces in the mechanism application?

[TomD.inPDX]

I have gone through great pains to emulate the motion I wished Creo would do for me.

You might be able to generate trace curves or intersects that you constrain your cam to.

[mkeller]

Okay,thats what I had in mind but I am not sure how to go about doing that. Do you have any tips for making a circular curve that follows a helical surface?

[gkoch]

Do you mean a helical curve? (can be done when intersecting helical surface with a cylinder through same axis)

Or a circle projected onto helical surface? (can be done by projecting a sketched curve onto the surfaces)

Or something else?

[TomD.inPDX]

Sorry Matt; I missed you reply and query.

Thanks Gunter for picking up on that.

You can intersect your as Gunter suggests; you can create a trace curve if you have a mechanism analysis defined; or you can create a 3D curve equation to use as a guide path for constraints.

It all depends on the accuracy level you require.  If the incline of the helix is constant, you can calculate the exact center of the roller axis and generate a helical curve from an equation at the center of the roller's axis.  You can constrain the cam's roller by using a point on the axis of the cam roller to the equation curve.  The equation curve can be created using parameters.

As with all things Creo, there really is no right answer, but many ways to accomplish the task at hand.

Seeing your application will be helpful in understanding the best solution.

A typical application for your original question may be a ball bearing lead-screw.