Constrain sketch block or points to a polyline/path in Master sketch

[flueckchuck]

Imagine if you were doing a master sketch (parametric layout) of a garage door assembly. The layout would include a track (path) and door segements (sketch blocks). The track is made up of straight lines and curved lines all connected with coinciden,tangency, and colinear constraints (think Polyline). In order to show its range of motion of the door along the track, you would need to constrain the wheel axes of the door segments to the centerline of the track (path). Unfortunately you can only constrain the axes to a single line segment of the path and not the entire polyline.
My idea is to create a sketch constraint that allows a point to be constrianed along a path/polyine.

[PaulMunford]

That's a good idea. Can you use a spline as a workaround?

[r_lehmann79]

Good Idea. I had the same problem few months ago.

I used the spline as workaround, but the result is a little poor.

I got deviations between the originial path and the spline, because a spline will never be as "straight" as a line and so it's "swinging" around the original guide lines and circles.

[flueckchuck]

I used a spline as a workaround originally before posting this idea. The block will stay coincident with the spline path; however, as r.lehmann points out, the spline is never straight and you need a large number of points in order to attempt to make the spline follow the theoretical path of a polyline. In my case, i am trying to get accurate minimum and maximum measurements between a train of connected blocks that are following a path. The spline causes inaccurate measurements. Thanks for thinking of splines as a solution, but it will not work for master sketches that require accuracy.

[Paul1084]

Great Idea, this would solve a whole host of problems for me, and simplify my parts no end particularly with frame generator where I have to use rules for each member path.... if I could constrain to a polyline (multiple attached segments) I could get rid of my overly complicated rules