Straightening wire

Thread Starter

cmartinez

Joined Jan 17, 2007
7,290
For reasons that unfortunately I cannot disclose here, I need to straighten #12 ga (0.080" dia) solid copper wire in lengths of about two meters. Total quantity about 100 pieces. Said wire must be as straight as possible, resembling a rod. It will be installed upside down, so gravity won't be an issue at maintaining its final shape.

Question, is there a manual technique that could be used for this purpose? Or would buying a wire straightening machine be recommended?
 

SamR

Joined Mar 19, 2019
3,179
The only thing I can think of is to draw it through a steel block with the hole rounded on each side so it won't "shave" the wire with the hole diameter the same as the wire or with a minimum clearance as possible. And not sure even that would completely straighten it but maybe worth a try and see.
 

JWHassler

Joined Sep 25, 2013
284
For reasons that unfortunately I cannot disclose here, I need to straighten #12 ga (0.080" dia) solid copper wire in lengths of about two meters. Total quantity about 100 pieces. Said wire must be as straight as possible, resembling a rod. It will be installed upside down, so gravity won't be an issue at maintaining its final shape.

Question, is there a manual technique that could be used for this purpose? Or would buying a wire straightening machine be recommended?
Roll it between two pieces of hardboard.
This works very well for shorter (30 cm) lengths, so maybe worth a try.
 
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drc_567

Joined Dec 29, 2008
1,088
If you have a bench vise with a 3 or 4 inch grip span, you can probably straighten the wire out in increments. It will take some patience, but the vise will be able to tighten up on each length of the #12 wire and give an acceptable result.
... Something to try possibly, if you are not obtaining sufficiently straight wire is to take a torch and heat a length of wire until it turns 'cherry red' color. Doing this removes any work hardening resulting from die forming, and should give a more easily shapable wire section.
 
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jpanhalt

Joined Jan 18, 2008
11,088
If you want it truly straight you need to use wire straighteners (left = wire straightener, right = slip rollers):
1605771952634.png1605772516311.png

If you have access to "slip rollers" (used with sheet metal to bend or straighten), they often have grooves for wire bending too. Only three roller are involved, and while you can get something relatively straight, the 5-roller versions are better. . A wire straightener may seem counterintuitive as it actually bends the wire. With proper adjustment of the rollers, it comes out straight.

Years ago, I made one for straightening piano wire that I needed for making some special springs. I used face-to-face cheap ball bearings for the rollers and shoulder screws for mounting them.

Of course any bending will work harden the copper.
 

ericgibbs

Joined Jan 29, 2010
12,198
hi cm,
If you can tolerate a small change in the wire diameter, clamp one end of the 2mtr wire in a vice and pull hard on the other end of the wire.
Wrap the pulling end around say a screw driver handle to give a decent pulling grip.

This is a method i have used.

Try a couple of short test pieces
E
 

Delta prime

Joined Nov 15, 2019
806
For reasons that unfortunately I cannot disclose here, I need to straighten #12 ga (0.080" dia) solid copper wire in lengths of about two meters
Hello sir.:)
How about after you straighten the 12-gauge solid copper wire can you tell us why ? You made it more interesting that you cannot disclose.:rolleyes:
 

upand_at_them

Joined May 15, 2010
759
In the manner of the tools in post #7 you might be able to use a brake line bending tool, the kind that has wheels. I have used mine for straightening heavy wire. If you can get two of them you could assemble three wheels onto a plate or 2x4 to use as a roller/straightener.
 

mtonge

Joined Apr 19, 2016
93
Any working of the copper wire (stretching, twisting, or rolling) lowers the metal's ductility, making it stiffer while straightening it. I am working on a project that requires short pieces (12 inch) of straight wire. I clamp one end to my work table, and the other end with vise grips. Using a piece of 2x2 wood (cut a bit longer than the finished wire length) as a fulcrum, place the vise grips on the top end of the wood and use the vise grip handle as a lever to stretch the wire. This might work for you too, but 2 meters of wire may stretch a couple of inches. Using a drill to twist and pull may work better.
 

jpanhalt

Joined Jan 18, 2008
11,088
The individual rollers are insignificant. Paired ball bearings are durable, cheap, and can be adjusted with washers to almost any wire size. The spacing is what determines whether the wire comes out straight or curved. It needs to be adjustable and reasonably rigid depending on the wire size. I suspect even 12 gauge copper will need a steel/aluminum frame. Maybe some plastic might work. Not sure.
 

Externet

Joined Nov 29, 2005
1,580
Attach one end of the wire to a bench vise held near the ceiling over 2 metres high. Bite the bottom end with a vise grip and push it down with foot. It will get straight.
Cut off the biten crooked lower end first; cut off the upper biten end to lenght next, holding without allowing it to drag on the floor not hit anything. Sort of as already suggested but hanging vertical.
 
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jpanhalt

Joined Jan 18, 2008
11,088
Yes, but they are more expensive than the cheap ones I used. Face to face with a washer separating them (if needed depending a wire gauge) works fine. I have done it, and it worked in practice too.

Has anyone here made those bearings out of 3D printed plastic? How did they work?
 
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