splines and tangencies

ok.

Does this bug anyone else?

I have created a cam, and used splines to create a good portion of the
surface.

Now, I was planning on giving the guy making the cam a few reference points
so that we could check the thing. I give a dimension from the "center" of
the cam to the center of a follower, which is tangent to the cam. ie: at
90deg, L = 1.625. At 265deg, L = 2.365.

Anywho, it turns out that you can't make a sketch object tangent to a
spline.

So I can't give the guy any reference dims over a majority of the cam
surface (I did use arcs in a few areas).

What's really mucked up, is that I *CAN* do a tangent mate or a cam mate to
the cam surface.

So why the heck can't I draw a sketch circle and make *IT* tangent to the
spline?

Anyone?

Bueller?

-nick e.

 

There is a way to sketch a line tangent to a spline, though it is a
bit cumbersome.

A line can be constrined tangent to a spline if they share a common
endpoint. In a new sketch, copy the spline using "Convert Entities".
Trim the spline end point to about where you want it (draw an
intersecting line and use the trim tool, then erase the line). Sketch
a new line, starting at the endpoint of the spline. If your options
are set for automatic relations, you should be able to add tangency
"on the fly". Otherwise, I think you can add the constraint
afterward.

 

Anybody who works with splines!

Jerry Steiger
Tripod Data Systems
"take the garbage out, dear"

 

Sure...

http://zxys.com/misc/spline-tangent-constraints.png

...