View Full Version : Looking for pliable (steel) wire for servo arm

07-24-2006, 12:17 PM
I need to make a servo arm out of some thin yet somewhat stiff material that could be easily bent into shape. I am thinking steel wire, but where to get it? My project is giving a model car a convertible ragtop, and it seems to me the easiest way would be to have a flexible servo arm (wire) that could just be screwed onto a standard servo horn and have the cloth wrapped around it. Any ideas on the project or where to get steel wire? Thanks.

Beau Schwabe
07-24-2006, 12:31 PM
1)Wire coat hangers?

2)RC hobby shops?

3)Your local hardware store?
At the local Ace hardware store, usually toward the back where hobby brass, copper, and aluminum sheets are kept, you can find
steel, aluminum, and brass rods that would work for your application.

If you need a lot of material, Electric fence wire works nice for many applications such as this.

Beau Schwabe (mailto:bschwabe@parallax.com)

IC Layout Engineer
Parallax, Inc.

Kevin Wood
07-24-2006, 12:46 PM
You could also try piano wire or a guitar string. See your local musical instrument store.

07-24-2006, 01:28 PM
Try the RC-Hobby stores.
They usually have a broad range of Piano-wire in the shop for just that purpose.

Electric fence wire?
I didn't know anyone still used single-strand wires for that anymore?
(Here we use plastic fibres of some kind, interwoven with metal strands. Easy to tie in knots, doesn't break and is very easy to see)

Don't visit my new website...

Loopy Byteloose
07-24-2006, 06:13 PM
Steel can be soft or hard. It all depends on the amount of carbon included.

Piano wire can be so hard that it will damage wire cutters [chip the blades] and should be cut by notching with a file and bending at the notch. It comes in larger diameters for push rods, but it cannot easily be theaded. It can be hairy to bend.

Brass brazing rod is a wonderful item as it is stiff and doesn't rust. Try a welding supply as they sell it by the pound. Larger sizes can be threaded easily for push rods. Usually there are only 2 or 3 sizes available. Bending is reasonable.

Guitar strings are quite handy for robotics. The wire is stiff, but not as stiff as piano wire. The problem is that there are lots of sizes and some are covered with a brass winding. At times this may be useful [for soldering], at other times it may be too big.

"If you want more fiber, eat the package.и Not enough?и Eat the manual."ииииииии

ииииииииииииииииииии Tropical regards,иииии G. Herzog [и黃鶴 ]иin Taiwan

07-24-2006, 08:23 PM
If you bend the piano-wire correctly, you don't NEED threads...

иииииииииии |
ииииииииии ======= Servo
иииииииииии |__

Push the end through the servo-horn and it'll stay put.
You can also get special fittings that clasps around the wire and the horn so that you only need a single 90degree bend.

Also, the RC-hobby stores often have threaded rods, too.

Those stores can be a bit pricey sometimes, but they have a lot of neat stuff...

Don't visit my new website...

Joe Fishback
07-25-2006, 09:09 AM
Steel piano-wire can be hard to cut, bend or thread. To soften steel wire, heat the section you want workиred hot with a torch or in a gas stove flame. After heating red hot let it cool slowly. This will soften steel. Brass rod is just the opposite, heat it and then cool it quickly with water. Wire that has been softened will work much easier, give it a try

ииииии Joe Fishback

-Robots are my friends-

kelvin james
07-25-2006, 12:56 PM
One possibility for flexible cable is the wound wire used in brake cables for bikes. You would need some crimp fittings for the ends.