Re: Cam and Follower mechanisms
You may remember the Automata tutorial I wrote based around a lobed cam? Intern, Dragos Vasilescu helped me update this for Creo 2.0 and I'll send you the draft, If you could review the document and feed back that would help with the final editing I will be doing this month. The finished document will be then be uploaded here and to www.ptcschools.com.
To answer your specific questions, in PTC Creo Parametric there are two ways to select the two halves of the cam connection. T
The first lets you select surfaces and to work reliably, these have to be joined at a tangent. Use the Autoselect option to let Creo find all tangential surfaces. A useful tip is to use small radii when modelling cams with steps in like snail cams.
The 'blue' line you spotted is the other way to define cams. Instead of surfaces, sketched splines can be used to define each half of the cam connection.
I hope this helps.