Model Boat Mayhem

Technical, Techniques, Hints, and Tips => Engineering Techniques and Materials. => Topic started by: MichaelK on December 15, 2011, 10:40:47 am

Title: Forging (bending) Piano wire
Post by: MichaelK on December 15, 2011, 10:40:47 am
Hi
I have to make another linkage for the fwd\rev linkage on my TVR1A steam engine.
The linkage at the moment has way too much slack in it. :((
I need to bend some 1/16" piano wire 90degrees (square), and also bend the end into a small (2mm) loop so that I can use a 2mm bolt to connect things together. :-)
Is it possible to heat piano wire to red hot, then bend\hammer it into a 90deg bend, (or a 2mm dia loop) then either quench it in water or oil, or even let cool down to room temp, and still have the same qualities that the wire had before the heating procedure? {:-{
Any ideas would be appreciated.
Mick

Title: Re: Forging (bending) Piano wire
Post by: tigertiger on December 15, 2011, 12:32:35 pm
Can you use welding rod? I seem to remember that it bends cold and holds a shape, could be wrong though.
Title: Re: Forging (bending) Piano wire
Post by: andrewh on December 15, 2011, 12:32:55 pm
Mick,

Basically yes; but do you really want or need to?

Piano wire is a high carbon steel sold in the hard state, and certainly you can soften the end by heating it and letting it slowly cool.

But in practice you probably do not need to re-harden it because the softenened wire is still very strong, and far less brittle.

But if you just need a loop - just bend a loop :}   Modern piano wire can be bent cold to form a 2mm loop - I use round-jawed pliers but purists might use a bending block with a 2mm pin in it

hope this helps,

andrew
Title: Re: Forging (bending) Piano wire
Post by: triumphjon on December 15, 2011, 02:30:28 pm
most model shops sell solder / crimp on ends for the linkage rods which have a threaded end to them , why cant you put a rose joint on the threaded end and remove the supplied bolt and fit onto your engine ?
Title: Re: Forging (bending) Piano wire
Post by: derekwarner on December 15, 2011, 07:17:41 pm
Mick - check out the DU-BRO range of linkages & rods & fittings @ your local hobby shop - they also have screwed rod .......an advantage is that these components can be adjusted to provide an accurate length between the servo & the steam valve & eliminate all free travel or slack...... :-)) Derek
Title: Re: Forging (bending) Piano wire
Post by: andyn on December 15, 2011, 09:26:08 pm
Am I missing something here, or couldn't you just bend it with a pair of pliers?  %)
Title: Re: Forging (bending) Piano wire
Post by: Big Ada on December 16, 2011, 06:09:25 pm
Some wire I bought at a Show fractures when you try to bend at 90 degs.

Len.
Title: Re: Forging (bending) Piano wire
Post by: andyn on December 16, 2011, 06:46:49 pm
Well thats not very good wire then....
Title: Re: Forging (bending) Piano wire
Post by: MichaelK on December 17, 2011, 01:19:27 am
Hi
Thanks for all the interesting info,
This morning I just bent a 2mm dia loop in the wire using pliers and a hammer, ;) and it all seems good!
No need for heat! :-)
Mick