Quote Originally Posted by Dave 53 View Post
Maybe look into a "tube roller". I used one to make this bike and it seems like it would work for your window frame project.
The issue with trying to roll/bend channel is that if you bend it one way the side walls want to go out (excess material). So you hammer that back in and it bends another way. I thought of making some sort of rolling bender specifically for channel. It would have to be capable of rolling in various directions for the window frame. I thought it would be a huge effort for something that may or may not have worked.

Rick