TomCrump

Thanks for the refresher course. I'm getting ready to this procedure today. Good timing on your part !

Flypaper 2

I was bending 1/16 piano wire with pliers long before Z bend pliers and Dubro connectors were invented

SrTelemaster150

If you heat music wire to make bends in landing gear, it will "bend like butter" when you make a landing.

CRX Turbines

I've done this on all of my planes and never had an issue with it bending on its own. I'm not talking about coiling 3/16, I am talking about putting a 90 degree bend before your gear. Ever tried this sir or just speculating?

Villa

Hi SrTelemaster150
I designed and built a foam winged, twin tail, pusher-electric plane that has tricycle landing gear. The front gear is connected to a small, light weight, $10, steering servo. The control rod to the steering wheel is around 1/32" diameter music wire bent into a "Z" shape so that it can absorb shocks and protect the steering servo. Works for me. How would you do it?

SrTelemaster150

Yep, I tried it on my Dynaflite PT-19. After every landing on grass I had to bend the gear back to shape. This was the bends where the gear was monted to the wing.

I then tried heating & quenching & it was so brittle it snapped when I tested it. Good thing I didn't try a landing.

Music wire is heat treated (hardened then tempered) for springyness/toughness. When you heat it that destroys the temper.

I got some more 1/4" music wire, cold bent it in a vice W/a larger cresent wrench for leverage & had no more problems.

SrTelemaster150

I was refering to "Z" bends where the pushrod connects to the servo arm. Your "Z" is probably a lot more span between bends. I can see the merit of your application. For tight "Z" bends in control surface pushrods I don't see the need for music wire.

CafeenMan

Everything I've ever read about annealing music wire and then retempering concludes that you need a solid understanding of metallurgy and knowing how hot to get the steel and when to quench it or else you're going to end up with brittle wire.

Z-bends aren't an issue. I use music wire because it stays rounder than softer rod such as threaded rod. Thus it seats better in a hole with better support all around. I don't think annealing it would cause any problems though.

SrTelemaster150

Quote:

Originally Posted by CafeenMan

Everything I've ever read about annealing music wire and then retempering concludes that you need a solid understanding of metallurgy and knowing how hot to get the steel and when to quench it or else you're going to end up with brittle wire.

Z-bends aren't an issue. I use music wire because it stays rounder than softer rod such as threaded rod. Thus it seats better in a hole with better support all around. I don't think annealing it would cause any problems though.

Just heating & quenching are not enough. It must be tempered (hardness drown out) to a specific point.

All this is moot as with a vise & something to to span a length of the wire (I use a 15" Cresent wrench used @ a shallow angle along the length of the wire) 90° can be accomplished by cold bending.

Annealing for pushrods isn't an issue. For landing gear it can be. Maybe not sp much @ the wheel hub, but my PT-19 uses a "Z" bend that spans several inches between the leg that goes up into the wing root & the leg where the oleo strut attaches to act as a torsion bar. Annealing those bends results in a torsion bar that bends @ the 90° bends on every landing on grass..

CafeenMan

I'm not arguing with you. I fully agree. Bend music wire cold. I make Z-bends from cold music wire. Sometimes it cracks when I bend it - usually when I haven't made one in a while and forget how slow I need to go. But that's why I make the Z-bend first and then cut the other end of wire to length. I can just keep cutting off cracked ends until I get it right, then chop off the other end and it's perfect.

I know the type landing gear you're talking about - standard issue up to the present for wing mounted gear in a grooved block and a torsion block. No reason to heat that wire at all. If you can't make a vise work then do what I did and buy a good wire bender. They last forever unless you do a whole lot of bending. I've bent landing gear for several planes as well as other items and it's good as new.

Check out these clamps I made several years ago - 3/16" music wire. No cracks. Not the roundest bends but that's a problem that happens when you don't clamp the wire and it slides while bending.

http://www.airfieldmodels.com/inform...d_edge_clamps/

LesUyeda

"Just heating & quenching are not enough. It must be tempered (hardness drown out) to a specific point."

You left out the point about getting real "piano wire" not the stuff that they are selling today, under that name:-))))))))))))))

Les

CRX Turbines

I was specifically talking about a 90 degree bend before the gear. I have never had an issue with it and if you bend it that sharp without heat, I have seen small fractures develop. I have had the gear break from these fractures on multiple occasions. At the end of the day, I'll take bent gear over snapped gear any day.

TLH101

My Feedback: (90)

http://vaillyaviation.com/images/Wor...re%20_web_.pdf

jaka

Hi!
It's easy!
Put it in a wise and bend by hammer it to a 90 degree bend...but see to that you bend it against a drill bit with adequat diameter.That's the important thing!
3mm pianowire -use a 3mm drillbit. 4mm pianowire -bend it against a 4mm drill bit and so on!. Never bend it against the sharp corners of the wise!!!
And most important! Never heat piano wire as the springiness dissipears!

Flypaper 2

Used to do exactly that with the drills, Jake. It was standard procedure at one time. Afterwards I put the notches in the vice jaws for that purpose.
Your right too Les. Piano wire 30, 40 yrs. ago was much harder than what's put out now. In fact I'd like to know where to find the good stuff. I've pretty well robbed all the good stuff out of my old kits.

grosbeak

I picked up my K&S Mighty Coiler and Wire Bender today - what a great tool! I used it to bend landing gear reinforcements for my two larger planes. Some photos:

Out of the box

K&S Mighty Wire Bender and Coiler


Assembled and clamped


Assembled and clamped


Practice coil bent from coathanger wire.


Test spring would from coathanger wire


Placing 3/16" wire for bending (brief experience shows me the bending mark should be about the wire's diameter past the apex of the base pin).




Placing the wire


Finished product.


Final wire




Installed.


Wire bolted on - 02

jameighan

Members,
I have utilized the K&S wire bending tool for many years and have taken it to the next step. All of my large size music wire bending is now performed on a 3/8" thick aluminum plate. Draw the pattern of your wanted music wire profile on the 3/8" plate and then drill holes in the plate for steel dowel pins ( just like the K&S bending block). Clamp the plate to your work bench and utilize the K&S bending bar to shape the music wire. I clamp the music wire in place to keep it stationary and inset the dowel pins as required to perform each bend. The 3/8" flat plate will yield all bends of your music wire in the same flat plane.

The 3/8" plate can be used over and over for different patterns by just punching out the dowel pins and start you next pattern. You can purchase the dowel pins from McMaster Carr and they are cheap. Purchase the 3/8" plate from your local scrap yard or machine shop. It dosen't matter if it is loaded with holes, just move your profile to suit the pattern.
FYI,
Jim Meighan

SrTelemaster150

It's been a long time but I think I used hardwood blocks in the vise. They gave just enough to make a nice radius on the bend. No cracks