Step 2: Tap and Bash
Short sharp bends can be gently tapped out aginst the benchtop with a hammer, the copper will easily yeild. The wire should be rolled during the tapping. Larger severe bends can be straightened by smacking down on the wire with the edge of the wood block or hitting the block with the hammer. You do not want to flatten the wire. Once the severe bends are smoothed out, clamp one end of the wire to the benchtop and rub the block, applying downward pressure, from the center of the wire to the loose end. The wire will quickly become hot, so it is necessary to unclamp and roll the wire frequently, otherwise it will curl. Clamp the other end and repeat the process. It will take a few minutes, but the wire will become straight. The block might work better if it had a shallow V groove in its bottom to run along the wire, but the plain block works so well that I have not bothered to try that.