Soldering is NOT one of my best attributes. I have received all kinds of info on soldering in a different thread, and MAYBE???, I will try again. (I had a clevis come off the throttle arm rod due to a bad solder joint and had to fly almost full throttle till it ran out of fuel!!). My question here is: What do you guys use for the keeper at the servo arm on 4-40 rod?? I have always used 2-56 rods and bent it 90 degrees, and used those nylon keepers. I am building a 4* 120 this winter and will be using 4-40 rod for the first time. I prefer NOT to solder anything... unless I have to. Does anyone use a die and cut treads on the servo end
too? Thanks .... lownslo

Resin flux will not stick very well to piano wire. Get brand named "STAY BRITE". solder kit . Try it . Done properly it won't come apart.

You could use 4-40 threaded rod the hole rod is threaded, or you could get a die and wrench from your hobby store for about 15.00 and thread how you wont. I don't know if is what you are looking for or not but good luck. Nick

Not a good idea to cut threads in 2-56 or 4-40. Problem is the factory threads are rolled in. If you cut threads they will be shorter on the height and deeper on the depth. This makes the female parts fit loosely. I bought the dies, I wasted my money. For throttle linkage I think I like cable and solder clevisis. Use a solder with at least 2% silver (more strength) and a little flux. It is pretty easy to cut the length right such that any travel adjustment can be made in the transmitter.

Thanks to all. I am glad that Parkerm explained about cutting the threads with dies. I may have wasted my money there !!.... lownslo

This came up on another forum. Does anyone just put zbend at the servo anymore? If not what is the problem with it. I use it all the time and its tight and will never fail. Have it on turbine roo, whiplash, diamond dust. No problems that i know of.

Zbends work, but my experience is that over time, the servo arm hole wears and creates play/slop, which can lead to control surface flutter.

Yes the servo arms do wear after a while. But I thought anything you put in there would wear. The larger rod compared to something smaller like a clevis would wear less. Or do you use something else altogether? Thanks

Not only do they work but in fact are the prefered method in all three classes of pylon racing, Quarter 40 and both Q-500 classes. The reason for this is reliability and safety. With the right tool and one of the best is the Dubro Z bend maker it can be done very accurately.

So jlong for small hi speed aircraft that you are flying it really is the best setup.

John

If you are going to thread the rods you will nbeed to buy 1/8 inch rod to use for 4-40 threads and 3/32 for 2-56 threads. Parkem is correct that the rods ar rolled threads on the stoe bought ones. I bot the Rodchuck Set from Rodchuck.com and they work quite well. I have done several planes this way since I bought them.

When using 4-40 rods at the servo, I silver-solder brass 4-40 rod ends to the rod and I use a 4-40 Sullivan clevis with the little keeper that comes with the clevis and a 4-40 plain nut to lock against the clevis (nut keeps the clevis from moving on the threaads and possibly wearing the threads). The 4-40 rod ends are made by Dubro, Great panes and Sullivan. They have a female end that the 4-40 plain rod slips into, then silver-solder. Before soldering, use coarse sandpaper to rough-up the the rod for better solder adhesion. I think the zbends wear the servo arm 'cause the vertical part of the zbend is not a consistent diameter due to the tool maybe leaving marks.

Your LHS should have some 4-40 rods with and inch or so of threads on one end with a quik-link already on it.

I like Z-bends, but they work only with plastic servo horns, especially the full round disc types. With some cross or star type servo horns, squeezing the Z-bend through the hole can split the plastic. I've had that happened to me many times - gets awfully frustrating - especially since I bought a Z-bend plier that crimps real nice and sharp 90deg bends. On the one hand, you have to keep the hole just big enough to slip the rod through, but if the fit is too tight it will invariably crack the plastic trying to get pass a 90deg bend.

BTW, soldering music wires works just fine, if you first sand it down to bright metal. That gets rid of any oxidation and oils that were on the surface.