Then there are these - https://www.jewelrysupply.com/Artistic-Wire-Straightener-Tool-with-Three-Rollers_p_20495.html#tab-1 if it's just a one off job.

 

I need to straighten #12 ga (0.080" dia) solid copper wire in lengths of about two meters.

Back in 1982 I worked for a burglar alarm company. When I wasn't installing I was repairing units. When I wasn't repairing units I used to straighten copper wire in probably about 3 meter lengths at a time. The way I did that was to clamp one end in a secure vice on a bench, then grab the far end with a pair of lineman's pliers and would jerk on the wire, snapping it repeatedly until it was straight. I used those straightened lengths to make miniature furniture, bicycles and other tiny models. I can't think of a cheaper way. Just don't snap so hard that you break the wire.

What you're doing is actually stretching the wire, thus, making it slightly smaller in diameter, but not so small you can see any difference.

 

this is pretty cool but more than you need for the job, just make the straightener

 

this is pretty cool but more than you need for the job, just make the straightener

Very clever machine.

 

@shortbus
Thanks. Couldn't find them at that price when I made mine. At that price, i would buy it assuming it was the right size.

 

Try printing them... I believe @cmartinez, you have a printer and why not? I'm not sure about you but I have many inexpensive bearing in my shop that I can print a tight fit for the roller die. It's only straightening 12G copper. If they were 12G stainless that's a different story. Make sure they have enough meat to them printed at 100% infill its compressive strength.