How do you connect a pushrod to a plastic bellcrank??

OK now that I have answered the Nobler 9 second lap problem, I have a question.

I have a Skyray that I am about to put the push rod on. The push rod is pre-bent with a 90 degree bend in each end. The plan calls for soldering two washers to the end. The problem I see is that in order to get the solder to melt on the rod, the plastic bell crank will melt. I see where Brodak makes this worm looking keeper.
What is the best way to secure the push rod to a plastic bell crank and control horn?

Thanks
Paul

>I have a Skyray that I am about to put the push rod on. The
>push rod is pre-bent with a 90 degree bend in each end. The
>plan calls for soldering two washers to the end. The problem
>I see is that in order to get the solder to melt on the rod,
>the plastic bell crank will melt. I see where Brodak makes
>this worm looking keeper.
>What is the best way to secure the push rod to a plastic
>bell crank and control horn?
>
>Thanks
>Paul

Do not use the "keeper". Although there are several methods that work if done correctly, including the use of a wheel retainer (I am always a bit afraid of these coming loose) and JB Weld, just plain old solder works quite well.

If you are putting a washer both over and under (a good idea) drill a hole in a scrap piece of pine at a 90 degree angle for the wire end to fit in. Make sure the wire is clean (a little fine sanding is good, but spin the sandpaper around the wire, not up and down) and put the first washer on and stick the wire into the piece of wood. This will hold the washer square. Now solder using rosin core solder. Do not use acid core solder as it will eventually (sooner than later) rust the wire. I like to use a solder with a higher melting temperature for this side, but it is not necessary. silver solder works, but is also not necessary. After soldering, clean the soldered area with alcohol.

Now slide the (nylon, not plastic) belcrank on the wire with its bearing, etc. You do not need to grease this. Then take a small piece of 400 or similar sandpaper and drill a hole in it the size of the wire and insert it over the belcrank, sandy side up (towards the washer). Now add the washer and, either holding the wire in a vice (or by a friend, wife, girlfriend, etc.) with the wire end up and the washer laying flat, heat the wire and washer at the same time until the solder is able to flow. When it flows around the washer, remove the soldering iron and let it air harden. Do not blow on it or it can cool too fast and get a poor joint. The solder should look shiny. When soldering this end, use a good 60-40 rosin core radio solder. It takes less heat and will give the strongest joint of a low heat solder.

The above should go fast enough that you won't melt the belcrank. The sandpaper serves as a heat protector in the operation, it provides the proper spacing, AND (you are not done with it yet) it helps to clean the underside of the washer from any "goo" that seeps through. So, when the solder has cooled, spin the sandpaper a few times to clean that washer before tearing it off. You can then clean it with alcohol again and admire your beautiful craftsmanship.

Use JB weld instead of Solder.
In either case, solder or jbweld, rough up the surface first - both the washer and the pushrod, clean with some alcohol, put a buffer piece of balsa between the horn and the washer and then have at it. The buffer piece of balsa keeps the horn clean and helps to deflect the heat of the solder - problem is the pushrod needs to be hot enough for the solder to bond. That's why I use JB weld.

I file or cut grooves in the end of the pushrod that sticks up through the bellcrank, then find a washer and thimble that just slips over the pushrod. Put the washer on first, then the thimble and crimp the thimble down in the grooves. Some JB weld as you slip the thimble on gives added insurance.
This works well with wheels also.

>OK now that I have answered the Nobler 9 second lap problem,
>I have a question.
>
>I have a Skyray that I am about to put the push rod on. The
>push rod is pre-bent with a 90 degree bend in each end. The
>plan calls for soldering two washers to the end. The problem
>I see is that in order to get the solder to melt on the rod,
>the plastic bell crank will melt. I see where Brodak makes
>this worm looking keeper.
>What is the best way to secure the push rod to a plastic
>bell crank and control horn?
>
>Thanks
>Paul
>
>I am a retread, - I did C/L in my youth and did not know
>what I was doing then other then having fun. And not much
>has changed.

You could just bend the pushrod end into a "z" (two 90 d. bends opposite each other) then "thread" it into the bellcrank. Or you could insert the existing "L" leg into the bellcrank from the bottom; then when installed it is trapped by the bellcrank mount floor.
--Ray

I use the "Z" bend myself, but that's on Combat planes. I don't know if it's slop-free enough, or durable enough for a full sized Stunter.

Another way is to sand where the washers are going to be but not the bearing (bellcrank or control horn) part of the wire.
Next, solder the first washer as described previously.
Then tin the wire (put solder on the wire) where the second washer will be, without the nylon part installed. Also tin the washer.
Finally, install the wire on the bellcrank or control horn, put the washer in place (with sandpaper separator) and solder.
By tinning the surfaces beforehand the contact time will be minimal to complete the joint. Since the wire is tinned, you only have to apply enough heat to melt more solder on.
Wash the joint with alcohol to remove any residual flux.

Enjoy your Skyray!

Hello,

We would used a paper clip. Wrap one end around control rod shaft and lead the other end to the "Z" bend and wrap around it. Allow for movement of control horn or bell crank. Works well. Henry:)

Try using a bicycle spoke for your linkage wire it has a head on it.