I have modeled up an old 8mm film projector.
My one last task is to have the film that is leaving the reel to ‘follow’ the reel as it unwinds and shrinks in the reel. This is the section of fim that is running to a film guide and then thru the projector.
I have computed a line from the center of the film guide to the center of the reel. I know the radius of the film in the reel. But I have not found a way to make the radius line at 90 degrees to the other line. the 2nd point of the radius line is at the point of tangency.
Two questions:
1. How do a place a line at 90 degrees to another line?
2. Is there a better way to find the point of tangency on a circle?
Thanks!
Ron Lindsey
