--OK here's the thing: I can get 8 gauge aluminum ground wire
in coils that are pretty tightly wound; i.e. about 8" dia. What I *need* are dead straight pieces, maybe 10 to 12ft long. I'm thinking if
I could clamp one end in a bench vise and yank the other end hard
enough I could take the metal past the ...what's the correct term,
elastic limit?, then I could straighten out the waves, kinks, etc, yes?
--So the question is, could I do this with a pair of pliers or
do I need to hook it up to the rear bumper of my truck?
--Any help appreciated,
Try clamping one end and chucking the other in a drill. Pull a little
tension on it and twist the wire with the drill while pulling slightly.
There's more than one direction you can yield the wire in.
I agree with your math, but the yield could be as high as 30kpsi
depending on what the alloy is.
Best way to straighten it is to put a long length (100 feet plus) in
tension to a few hundred pounds, then run a screwdriver blade down the
whole length. That will will take out all the small wiggles, leaves it
with some large swirls to deal with. Dead straight is going to be
Ned Simm> >
Fab up a roller straightener. See ebay item 7527787746 for a not-great
picture of one on a Eubanks wire cutter/stripper, on the front left
corner of this machine. These use 4 rollers over 5 rollers followed by
4 rollers beside 5 to straighten in both planes, with a screw to set how
close the rows of rollers are to control how much the wire gets bent
back and forth. On our Eubanks I aim for maybe 1/2 the overall wire
diameter deflection when feeding 14 ga insulated wire and it comes out
pretty straight. More deflection would be straighter but the pulling
resistance gets out of hand and we don't need it any straighter :-).
For a quick-and-dirty setup just use some small pulleys, maybe .75-1"
diameter, and start with just one plane, to see if it will do your job.
Carl Ijames carl.ijames at verizon.net
The problem with just plain tension is that the wire will not reach the
yield stress along its full length at the same time. It will probably start
to elongate in some areas before others. A part that started out nearly
straight may still have its original curvature after you're through, while
other areas could actually neck down.
I like all the replies given so far. I straighten alot of copper wire in
8 foot lengths. My copper is possibly enough different from the
characteristics of the aluminum you have that this wont be beneficial to
Any of the slight bends that dont straighten by pulling can be
straightened quite well by rolling the wire on the clean garage floor while
tapping the wire with a plastic (dead) hammer.
I inherited a rod straightener with a shop stock that I bought years
ago. It consisted of two sets of three closely spaced ball bearings
installed at right angles to each other. The middle bearings had a
screw adjustment to change the tension. The whole thing was mounted on
a 6" X 8" plate that could be clamped in a vise. It would straighten
coiled rod stock dead straight for a fabrication operation by drawing
through the bearing set.
The term you were looking for is the yield point.
I have done it with #10 steel wire. Clamped off one end to an eye bolt on
the wall across from the big vice, tied the other to the wide open vice jaw
and then closed the vice. May take a couple of cycles. Just keep
stretching and shortening up until you get a smooth cantenary when you slack
off. Aside from some ominous creaking from the shop walls it works great..
#8 aluminum should be a piece of cake.
You got it!!eggzakly right--I use a pr. of visegrips & twist the wire
around them one more time..set up a good pull (you got a heavy vise
doncha?)--then whack the pliers with a 2# shop hammer---works for me-
I straightened some 3/16" S.S. tubing this way. JERRY
The wire straighteners that I'm familiar with were rows of ball bearing
assemblies (maybe 10 pair) with grooves in the outer races. They were for
steel wire that was payed out from large reels, and were adjusted to just
slightly under the wire diameter. These were very effective for wire mill
I've seen it mentioned several times that numerous folks have used 2 boards
lightly clamped together to pull the wire thru. Some were wanting to
straighten piano wire, and used a drill to rotate the wire as they pulled it
thru the boards (although they weren't taking it off spools).
I haven't tried this method, but it would likely be a low cost plan. 2 pairs
of boards oriented horizontal and vertical should be fairly easy to set up.
A shallow groove should be enough to guide the wire.
If the wire pays out from the coiled diameter straight into the groove, it
should be fairly easy pulling.
--Thanks to all; a number of good ideas! I'll buy the material
and take a whack at this today and report back tonight. I really only
need relatively straight lengths of maybe 10ft. so I'm thinking the
slide hammer and hand drill approaches are worth a whack, so to speak.
WHat I'm aiming to make is stuff that I can bend around a form, to make
an "armature" that matches the outline of a "two decker" sail-era
warship. I've got to make a dozen that match, each about 2ft long and
maybe the same in height. I figure I'll make the form out of a hunk of
plywood with nails at corners and bandsawn bits of MDF for the curvy
parts. When I'm done these 12 will be covered with EL wire, then
positioned on a grid. The EL wire on each individual ship will run to a
separate channel on a sequencer, so that the ship appears to be
"sailing" on a "sea" which is also sequenced, but in a slightly
different scheme. I've got the "sea" done and it works pretty neat.
One type of straightener I've seen in some mechanic's kinks books is a
piece of tubing bent in a lazy "Z" shape, like 10 or 15 degrees off
axis for both ends. I've used this in EMT for thin wire(#16 copper),
bent with an EMT bender, it worked. Just pull the wire through and it
gets straightened out. For 8 gauge, you might want to go to 2" tubing.
I've seen a similar thing using wooden cleats nailed to a support
board, the path was the same. Probably wouldn't last as long as the
Let us know what works.
: What is EL wire?
--Electroluminescent wire that mimics neon tubing, but is
bendable, solderable, etc. Very neat stuff. There are a number of folks
that sell it but my favorite is coolneon.com because they have "soldering
parties" where they show you how to work with the stuff; they have
sales then too and they extend bigger price breaks for quantity buys.
[ ... ]
Unfortunately, on a fixed-pitch font, it shows up with the lower
roller to the right of both other ones. I somehow doubt that was what
Better to switch to a fixed-pitch font before drawing something,
and then *warn* people to read it with fixed-pitch as well, because
different proportional pitch fonts (or the same proportional pitch fonts
on different machines) behave differently, so your "drawing" is likely
to be distorted on various screens, and not show what you intended.
I'll try to change it so it looks right with a fixed pitch, and you can
see how far off it looks on your proportional pitch font.
I added one more underscore between the two top rollers to allow the
bottom one to be properly centered.
Now that you have seen how bad it looks, select a fixed-pitch
font like Courier for your newsreader, and see what it looks like. (And
what your original looks like, for that matter. :-)
--Current status update: aluminum grounding wire is now
outlawed in Sonoma County so it's unobtanium; couldn't even find it at
the local junkyard! OTOH I *did* snag 2lbs of aluminum welding rod for
five bucks. It seems to be bendable, if in short 36" lengths. Have
ordered 100ft of the grounding wire from coolneon in Oakland and hope
to take delivery one day soon...