Michael Beckman

My Feedback: (1)

Hey all;
This is the greatest place to get information so I thought I'd ask the group, cause someones got to know. I am building Wendal Hostetlers Cessna 150 and I thought that I would hide the elevator pushrods inside the fuse. This requires a larger than normal elevator control arm. You know the one I'm talking about, piece of steel rod bent on both sides to go into the elevators with a control horn welded (soldered?) to the center for the servo to connect to! does any one know of where I can get a heavy duty one, OR have a suggestion on what to do. I do not want anything outside the fuse.

Patiently waiting for your responses

Michael Beckman

BMatthews

You'll likely end up making your own.

Or depending on the size needed try Brodak Manufacturing and see the control line horns at
http://www.brodak.com/shop.php?CategoryID=83

Michael Beckman

My Feedback: (1)

Try'd to make own, but don't own any welding equipment. Any suggestions?

Campy

My Feedback: (1)

Bend a piece of 3/32" or 1/8" (or larger if it is a BIG plane ) music wire to connect the 2 elevator halves together.
Next get some 1/16" (or heavier depending on the model size ) sheet brass.
Mark the outline of the horn on the brass, BUT DO NOT CUT OUT YET.
Now drill a hole for the wire that connects the elvator halves and a 1/16" hole for a METAL PIN clevis.
Now you can cut the horn out.

Clean the horn up and emory/sand the center section of the elevator connecting wire.

Slide the horn on the wire.

BLOCK THE WIRE IN A LEVEL POSITION and adjust the horn for the angle you want/need.

Solder with a SILVER SOLDER. I can highly recommend Stay-Brite solder. Their flux is a liquid and excellent.
Use at least a 60 watt soldering iron to heat the center of music wire and solder.
After everything has cooled, clean the solder joint and TEST the horn to be sure you got a solid solder connection.

I like and use Sullivan clevis because of the locking clip.

Install the clevis to the pushrod and install. Be sure that you either solder the clevis to the push rod or use a
nut to jam the clevis so it will not move.

Remember, you will ONLY BE ABLE TO ADJUST THIS FROM THE SERVO END, so make sure everything is correct
before sealing the fuselage (and access ) up.

OldScaleGuy

My Feedback: (2)

Although Stay Brite is a great product, I would not advise it on a plane the size of the 150 you are building. Take your parts (only bend one side of the joiner wire to begin with) to a local tool shop, welding shop or machine shop and ask them to braze the two parts together and then make your final bend in the joiner wire. The brazing process, done properly will hold indefinately.

cutaway

Home Depot has a cheap Bernzomatic brazing set for about $50-60 that can do small work. Plan on wasting one oxygen bottle getting the hang of it. The MAPP tank lasts a lot longer than the oxygen.

Once you got a rig like that, you'll be able to fab any sort of custom horns you might ever want. At $12 a throw for the pre made ones, that aren't always shaped the way you really want, it doesn't take too many before it pays for itself. I made a half dozen custom horns on the first tank of oxygen and used'em all up already.

fledermaus

Brazing music wire is pretty easy, as cutaway said. I just fabricated a set of landing gear for a Sopwith Camel using 35% silver brazing wire to join 1/8 and 5/32 music wire - my first brazing job and it went really nicely.

You don't need to invest in an oxy torch if you don't want to. I used a simple single-tank torch with a pencil-flame tip. The fuel was labelled as "Brazing Gas" but it was actually propene (NB NOT propANE). Safer than acetylene, doesn't need oxy and heats up plenty hot for brazing.

If you want to see my Camel gear to get a sense of how easy it is (remember, this was my very first brazing job), visit the RC Scale Aircraft Forum at [link]http://www.rcuniverse.com/forum/m_6328853/tm.htm[/link].

OldScaleGuy

My Feedback: (2)

Looks great. In the U.S. the brazing gas is called MAPP gas available in most home improvement centers such as Home Depot, Lowes, etc. and it does a very good job in securing parts like your elevator horn to music wire.

Michael Beckman

My Feedback: (1)

Thanks to all of you for your resposes. I am familure with Mapp Gas and have a bottle already. Do you use any kind of flux with the brazing rod and can you get brazing rod at the local home depot or lowes? Is there more than one kind of brazing rod available and what do you recomend?

Michael

BMatthews

There's a wide variety of high strength silver solders as well as brazing rods.

I'd suggest you look into a silver solder that will melt and join the metals at some temperature well under red hot so that you minimize the effect on the heat treating of the music wire.

Note that this does not mean using a silver bearing lead tin solder. While such solders are of higher strength than simple lead tin alloys they aren't really correctly called silver solder. The proper silver solders will not melt from contact with a soldering iron like the silver bearing lead tin ones will do.

And generally silver solders require a separate flux. Not the regular soldering flux either. You need the right stuff. I don't know about lowes or other more home style stores but any decent welding supply outfitters will have the silver solder in a variety of temperature ranges as well as the right flux. The flux I've used is a white paste in a little jar.

To use this solder I'd suggest you cut off a short length of the solder wire and bend it around the music wire and snug it up against the horn. Then apply the paste flux and heat. Doing it this way will ensure that when the heat is right the solder will flow. As soon as you see a nice fillet and it sucks down into the joint remove the heat to avoid overheating the music wire any more than absolutely required.