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Topic: Bending Music Wire
Message: Posted by: Darkwing (Jan 8, 2012 11:09PM)
I have searched both the Magic Café forums and other internet forums and getting mixed answers.

I am trying to get some pretty precise bends with 1/8" and 3/16" dia music wire. So far with some mixed results with a wire bending jig.

My question is can I heat the wire with a butane torch to just before the wire gets red and make the wire easier to bend? Will this affect the tensile strenght of the wire, make it brittle or what? I know enought not to quench the wire so not to make it brittle so do I just let the wire cool on its own to maintain its strenght. I just need some guidance to fill in the blanks.
Message: Posted by: Bill Hegbli (Jan 9, 2012 12:37AM)
When I toured a metal shop, they said heating a metal takes out out the straight, then reheat to reapply the strength.

No, you should not heat the wire with a touch, that will make it brittle. The heat is a low slow heating process.

There is a forum in this section on spring hinges. It has references to web sites about bending and rolling music wire. The process is to heat in an oven and bend and then heat again to but the strength back in it.

I know what you mean on a 3/16" wire. That is really hard to do. Best to take it to a machine shop to get it bent. They should have a machine that will be able to bend this thick a wire.

If you have a large vice and a hammer, then pounding it will work, but it will take a while.
Message: Posted by: MentalistCreationLab (Jan 9, 2012 12:35PM)
Darkwing something like the tool shown below may solve your problem, the only down side is you will need to build it yourself. Once its built it will last for ever. The one shown is well over 15 years old.

This tool is part of my specialty built tool collection and this collection contains many custom made tools built by me and a few anonymous friends.

Here is one of these tools that transforms a pair of pliers into a bender, it will nicely bend thinner wire and flat stock up to a 1/4" wide and 16 gauge. Perfect for making small wire apparatus as the bends will be straight and it will account for some spring back.


http://i202.photobucket.com/albums/aa120/bllmontana/100_1071.jpg

http://i202.photobucket.com/albums/aa120/bllmontana/100_1074.jpg

http://i202.photobucket.com/albums/aa120/bllmontana/100_1073.jpg

http://i202.photobucket.com/albums/aa120/bllmontana/100_1076.jpg

http://i202.photobucket.com/albums/aa120/bllmontana/100_1075.jpg


While one can do the same on a vice, the problem is that often the wire is not straight and it takes too long in terms of time to adjust the vice as where this custom hand model allows for quick and accurate work.

Later I post up some more of the special application tools if any one is interested in a separate thread.
Message: Posted by: thegreatnippulini (Jan 9, 2012 06:53PM)
Darkwing, PM me and I'll clear up a whole mess of misinformation on this page so far.
Message: Posted by: Mike Maturen (Jan 9, 2012 07:31PM)
Nippulini:

Why not just post it here so we can ALL benefit?
Message: Posted by: Michael Baker (Jan 9, 2012 09:16PM)
MentalistCreationLab,

That's a pretty cool little tool! Kind of a mini bending brake built onto a pair of channel locks.

I doubt though that it would work for the diameter that Darkwing said he needed to bend. Any suggestions for the larger diameter wire?

Also, related but a bit off topic. Does anyone have suggestions for bending flat bar aluminum into curved shapes. I had to do this a few years ago to make arm shackles for an arm amputation. I was able to do this with a lot of banging and cussing using a vice, a large hammer and some turned wood as a basic form. It was not easy. I was using 1/8" x 2" stock.
Message: Posted by: hugmagic (Jan 9, 2012 09:35PM)
I guess I don't think about it as I do it all the time. It is just a feel thing and do it with pliers. I use my hand to hold the other side. I've got pretty strong hands. I usually can handle .041 on most things. Larger than that, I have to cheat and use a vise or mandrel.

I use heat to re temper the spring wire once I bend it. I bend it cold.

Richard
Message: Posted by: thegreatnippulini (Jan 10, 2012 07:01AM)
Richard, unless you heated and quench the steel, there is no reason for a temper heat treat. Unless the steel is high carbon, temper treats are redundant.

Michael, you mean bending flat bar the "hard way"? It's a toughie, and one of the "for the course" practice excersizes for most apprentice smiths. You need to upset on side of the bar while fullering out the opposite side. This requires a good 2-1/2 pound cross pein hammer and a solid anvil to work on. Seeing how you're using aluminium, heat is not necessary.

For Mike Maturen (et al):
"Heating steel actually makes it softer. Heat treats for metals go like this: forging heat (enough to make it plastic to bend),normalize (after forge heat has been lost), anneal (soften), quench (harden), temper (stress relief). At the sizes you reference, air quenching MAY be possible. To avoid air quenching, anneal the metal after bending. I am assuming the wire is round. I will also assume the bends will be hidden?

A right angle bend should be made in a vise. Clamp the wire in the vise where you want the bend to be. Judicioulsy heat the area for the bend (about 1/4" of the steel), careful to not overheat or you'll burn the steel. But unless you have an oxy/acetylene torch you really don't have to worry about that. Once the steel is red to orange, bend the wire down and lightly hammer the hot area so it is 90 degrees flush with the surface of the top of the vise. Do NOT put it in water. Music wire is a medium to high carbon steel, quenching in water WILL make it brittle. If you let it cool naturally, it will normalize and should keep its shape. If you let it cool very slowly (1-2 hr to an hour) it will anneal and bend super easy. To toughen up the corner bend, lay it on its side on the vise (or other heavy piece of metal) and hammer it a few times on each side after normalizing. This will "work harden" the normalized area, it will also square up the round rod.

The radius bend can be made a few different ways. The easiest for you would be to take a piece of round steel the thickness of the radius, clamp it in the vise vertically. Heat the music wire again to red-orange, about 1/2" or more. Hold the wire against the upright round rod of steel in the vise and wrap it to form a "U". Then put it in the vise and pull one of the legs of the U out until it forms to 90 degrees. Now you should have a corner piece with a radius bend."
Message: Posted by: hugmagic (Jan 10, 2012 07:54AM)
I( was told by a spring manufacturer to retemper the wire. It does make a difference in this case.

Richard
Message: Posted by: thegreatnippulini (Jan 10, 2012 10:13AM)
Bending carbon steel cold "CAN" work harden the crystalline structure of the steel. Knowing the exact alloy helps, but in most cases (as in the term "music wire") the alloy type is unknown. A light temper can relieve some of the stress you put into the steel by cold bending. You're not "re-tempering" anything, as the wire isn't sold in a tempered state, so you are actually giving it a good first time temper. If you heat it past the point of the highest temper, then you just normalized the steel. 300 series stainless, for example, by nature is austenitic non-magnetic. Cold work can make the material slightly magnetic, and increases the hardness up to 45 - 50 on the rockwell hardness scale. Heat it at ANY point and both characteristics are lost. Steels can be fickle, knowing exactly what you are working with can make a world of difference.

English language: It took a blacksmith a long time to forge a piece, anneal it, file it, quench it, then temper it. If the smith wasn't paying attention at the temper point, the heat color would go past what he was attempting and the temper would be lost. This made the smith very angry because now he had to do the whole thing all over again from the start. People would hear the smiths expletives, I'm sure, and would wonder what was going on. The reply was "I guess he lost his temper", hence the phrase trickled into our everyday vocabulary.
Message: Posted by: Michael Baker (Jan 10, 2012 10:41AM)
Nippulini,

Thanks for the info. I sent you a PM.

~michael
Message: Posted by: MentalistCreationLab (Jan 10, 2012 10:55AM)
[quote]
On 2012-01-09 22:16, Michael Baker wrote:
MentalistCreationLab,

Also, related but a bit off topic. Does anyone have suggestions for bending flat bar aluminum into curved shapes. I had to do this a few years ago to make arm shackles for an arm amputation. I was able to do this with a lot of banging and cussing using a vice, a large hammer and some turned wood as a basic form. It was not easy. I was using 1/8" x 2" stock.
[/quote]

http://www.diacro.com/

You can find some of these machines at tool auctions from time to time. When I was doing the Iron and metal thing I had several of these and I can say that round table bender is wonderful. Got mine for $50.00 with some tooling at an auction. Also for some heavier stuff up to 3/16" the ring roller from Harbor F is ok. Now if you use the upright bender its not bad, there are better models. Just watch out the scroll bender attachment will need to be re milled so the side walls are straight or you will have crooked scrolls.

Also there is the farm bender
http://i202.photobucket.com/albums/aa120/bllmontana/farmbender001.jpg
I posted picks of this a while ago here on the Café. Plans for this type can be found online.
The nice thing about this style it can be scaled down to a smaller size and will still bend a lot of stuff.

Also, for somethings look at brake line benders, the type that is made like a spring are very nice for simple curves.

Then there is the wood block mounted to a heavy bench. All you need to do is add some holes and insert a few pins or bolts as a jig.

Now the problem with piano wire is that when its bent it can break at that point very easily. Normally when one bend steel it strength becomes stronger. However this is not the case with piano wire or music wire it becomes weaker. Its also a springy type of steel this will increase your spring back ratio and you may need to over shoot the bend so when it springs back it will be where you want it.

For very thin stock I used a saw makers vice for simple bends.

http://www.jonzimmersantiquetools.com/tools/saw_vise_sargent_a.jpg

That was the first photo I found online doing a search. These type of vices were made for sharping handsaws.

The farm bender will bend 1" thick stock without a lot of problems as long as you got the guns to make it happen. I am done doing heavy work. That farm bender I made is available for free to anyone who is a regular user of this thread, provide you pick it up. Rather see it go to someone who may use it then collect dust in my shop.

Well that about all I got for metal bending. If anyone has any question feel free to drop me a line as I am always happy to help when I can.
Message: Posted by: Michael Baker (Jan 10, 2012 12:52PM)
[quote]Then there is the wood block mounted to a heavy bench. All you need to do is add some holes and insert a few pins or bolts as a jig. [/quote]

This is the kind of sticks and rocks thinking that I can appreciate, and precisely what I probably needed to do my job more efficiently. For the occasional one-off, it's not practical to buy a special tool for the job, both economically, and in terms of shop/storage space (which for me is beyond critical).

What I was hoping for was a way to somehow secure the stock during the process, which involved a couple different kinds of bends.

I sent this following info to Nippulini, our resident metal-working guru, but as I've already caused this thread to take a hard left, I might as well go ahead and drop it in here...

Here is a photo of the pieces in question:

[img]http://themagiccompany.com/aa_wristshackles.jpg[/img]

The bend on the unseen back side is pretty much the same. They hinge at the back and lock by barrel bolt on the front. The front and back ends both align to lay flat on a horizontal plane, and the center forms a "wicket" for the arm. The smaller one was definitely the hardest to make... tighter curve and all that.

The biggest problem was trying to keep from undoing the previous bend while making the next. In other words, I'd make a 90 degree bend at one end first, then start the half circle bend. Finally the other 90 bend. I used a length longer than needed for extra leverage, and cut off the end waste when I was done. The rivets are just for show, BTW.

All in all, they ended up more as a series of sharp kinks that eventually became somewhat half circle, but definitely not smooth curves. On stage it doesn't matter and they do the job, but I thought there should have been a better way.

Any thoughts on how to secure the bar to avoid that "undoing the previous bend" problem? I can think of other applications for similar pieces, so was hoping there might be some possible ideas for a forming jig or something.

Thanks in advance to you guys... the "more heads are better than one" club!

~michael
Message: Posted by: Darkwing (Jan 13, 2012 11:50PM)
TGN

I did what you said to do and it worked. We now have a very strong 5/32" wire gimmick that works very well. Thank you for your advice and sharing your experience with a very novice blacksmith :). It really was a lot of fun and I felt I learned something new I can use down the road. I even looked at a small anvil at Harbor Freight.

David
Message: Posted by: thegreatnippulini (Jan 16, 2012 08:21AM)
Glad to be of help. Good to hear of the success. Those HF things are called ASO's, (Anvil Shaped Objects), not good for real smithing, but okay for small work. ASO's are cast iron, "real" anvils are wrought iron bodied with tool steel plate welded to the top. "Real" anvils are at least 100 years old and are VERY expensive (run around $2 to $5 a pound).

Enjoy your prop!
TGN