Alignment Equipment

I've been thinking lately about doing my own car alignments. I haven't made a decision either way, but I'm trying to sort through all of the issues. Here's a picture of someone's homemade alignment rig:


For instance, what kind of equipment would I need? Most of the work can be done with basic tools (wrenches, tape measure, string, etc).

I think that the main problem with doing alignments is eliminating the friction between the tire and the ground. You need the full weight of the vehicle to be sitting on the tires. But when that occurs, it is very difficult to steer the tires left and right. Furthermore, that friction creates forces and moments that prevent the wheels from going to their natural positions (preventing you from being able to measure the toe correctly, for instance). I have seen that some people have solved this problem by parking the tires on top of a stack of two vinyl flooring tiles that have grease smeared in between them.

I see that Pegasus Racing has a full suite of alignment tools to choose from. I might start there.