Best place to get frame rails for general purpose robotics?

I’m trying to make a friction wheel launcher, similar to this one. Sadly, the kit it was made with is no longer available. I’m looking for some type of adjustable rail system that I can use for this project, as well as others in the future. Going with something like 80/20 (T-Slotted Aluminum) would be good, but it is outrageously expensive. Any ideas?

submitted by /u/toliger
[link] [comments]