I created a enamelled copper wire straightener!
And how I did was I used fusion360 and the mcmaster part warehouse and found a grooved ball bearing
Downloaded it, and than exported it to .stl
Than I opened it up in tinkercad, and made three copies of it on the mat
and, than I cut the top off it, and the bottom of it, and left the grooved part
Made what was left of it, a solid model. Than I used the tinkercad cylinder model to create an exact sized hole in
it for a bearing that I took out of hard drives. I beleive the bearings came from the actuator arms. But not all drives have them
The hole was exactly 8 mm I believe. I printed off like ten of the grooved parts, and than popped the mini bearings into it, and than
used threaded self tapping screws to bolt it down to a wooden shim i got for free at home depot.
Total Cost, was only the 3d printer filament, which was 1 gram per roller. So about 5 cents CAD and time spent!
It really rocks out hard! bUT, AFTER a few wires went through the rollers started working themselves loose.
So, i put a couple of dabs of gorilla glue on the outside of the bearings, and pressed the rollers back in place
Keep spinning so the gorilla glue does not seize the rollers. Now, they are all seated permently, and it straightened my wire really good!

Just take your wire, weave it through the rollers, than grab needle nose pliers, or what ever your comfy using. Than drag the wire through!
It has not damaged any wires yet! And they come out perfectly straight after!