Formed Datum Curve - WF2.0

[freerangequark]

I am trying to form a datum curve around a cylindrical surface for the purpose of making a helical datum curve.
(I cannot use an Rho,Theta,Z equation for this datum curve).

I am able to WRAP the straight datum curve onto the cylinder's surface. The pitch is determined by the length of the straight datum curve (measured perpendicular to the axis of the cylinder). When I increase that dimension to a value in excess of the cylinder diameter, the formed datum curve fails. Why? How can I stop it from failing?

Thanks,
Glenn

 

[jeff4136]

From your description I'm not certain what the problem
might be. The two reasons for a failure I can think of
are ...
1) You're using an inappropriate Origin; Center (sketched
curve midpoint) or (sketcher) CSys. The plane normal
origin projection must intersect the target surface.
Play with the function a bit. It's pretty logical.
2) You're running the curve off the end of the cylinder,
in which case you can use the Trim at Boundary Option.

FWIW, my problem with the Wrap function for helical curves
is the grande part bounding box that can be the result.
You might reconsider Curve from Equation (it can be linked
to model parameters) or consider a helical sweep (or VSS;
requires you to hold your mouth just right but is probably
the easiest to set up once you know how) and (gives you a
cylindrical surface association) intersection curve.