I borrowed a friend's pipe bender, but it was only for 0.5" diameter tubes. The smallest I found at Lowe's was some so-called half inch copper colored conduit. Being impatient, that's what I bought. The diameter was really about 0.65". Being crafty, I figured I could make it work, and kept the tubing.
I determined that I could flip the bending lever around, and then 3D print parts for larger pipe. I successfully did this, and it looked like it would work.
But upon trying, the first thing to bend was the solid pin going through the middle of the circular portion of the tube bender. Darn cantilevering.
I strongly suspect I ended up not buying pure copper pipe, as that should be soft. At least my friend wasn't annoyed, merely surprised.
Copper pipes can be bent just like a normal rod, without specialized bending tools, if you fill the pipe with sand. After modeling the desired shape, the sand is removed. There are some YouTube videos of how to do that.
As a former trumpet maker, allow me to suggest you could try annealing the copper. Best done this evening, outside. Get a propane torch with a big flame (a cheap one won't work work, needs to be the "swirl" flame type or even a weed burner, or possibly even a gas kitchen stove) and brush the flame over it until it just barely starts to glow a dim red (which is why bright lights are not a help). Do not quench - just put it somewhere safe and let it air cool.
The copper tubing that is actually half inch in outisde diameter (around .430" ID) is typically sold in a roll and already quite soft - used to use this for quick mockups of french horn crooks. It looks like what you got was "pipe" rather than tubing.
I came up with a ridiculous improvisation a few weeks ago: A large so-called box wrench can be used to make a bunch of bends and achieve curvature. The inside radius gets dented, but I wasn't going to use the tube for liquid/gas purposes...
The project is very low priority, so in the mean time I have the remaining 8+ feet of pipe just sitting on the floor behind the couch...
Copper pipes can be bent just like a normal rod, without specialized bending tools, if you fill the pipe with sand. After modeling the desired shape, the sand is removed. There are some YouTube videos of how to do that.