[jlsanborn]

There's a couple schools of thought on bending. I was taught to use centerline and bend radius while a lot of other people use the "take up" method. I'd bet that Imperial bender will come with an instruction sheet based on the centerline method. I've got ACAD my shop PC and use that to sketch up the goofy bends. My -4 bender is from Aeroquip and the rotating handle is also on a swivel, which is nice!