Hi,

Hope someone can answer this quick question i have......

When connecting pushrods to the servos, i am using a superzbender tool which lines it up excently, but it leaves no room to put a plastic retainer ontop as well ? someone told me if im using a Z-Bender it will be fine without these as it will never come out !!!!!!!

Is this true ?

Thx

Yes!

A properly formed Z bend with your tool is a superior method and more reliable than the 'ninety degree bend/with retainer' method.

John

Ok thx guys, just needed to check

And if it DOES come out, I think you have bigger things to worry about

Well, think of this. Poke yourself with a straight tooth pick. That hurts.

Now, poke yourself when you have put a "Z" bend in the tooth pick. Which hurts worse?

The straight tooth pick hurts worse because it is not weakened.

It's the exact same thing when you put a "Z" bend in a wire. It weakens it. I've put "Z" bends in a G.P. Spitfire once and the wire split right where the Z bend was made. I'd stick with the E.Z. Connectors and the metal clips. Just a good 2 cents worth.
Clint

Another common mistake made with 'Z' bends is to attempt to make them with music wire. That is much to brittle and will fail. Only use 'Z' bends in soft wire such as the typical threaded rods.

Over the years I have seen more failures of various types from clevis' than 'Z' bends and yes all the methods of every type have their own failure modes.

That is true, but at least you don't weaken anything and you can keep the length of your rod rather than cutting 4" off just to make a Z bend, that WILL fail sooner or later. In my 4 years of flying model airplanes, I've NEVER had an E.Z. connector w/ the metal clip ever fail on me. And I can safely say that it's NEVER happened to me. Thanks.
Clint

Everyone has their favorate way of doing control linkages. I personally won't trust EZ connectors on flight controls. I think they have too many failure modes. I've seen the set screw vibrate out enough to allow the rod to slip, and even the metal retaining clips don't always stay put. I also don't like how high above the servo arm the pushrod is, it causes a twisting moment on the servo arm that can cause control slop on a longer control arm. But I know people do use them with out problems on slower, .40 size and smaller planes. It's worth noteing that I've never seen a 4-40 size EZ connector. I do like EZ connectors on throttle though.

Z-bends are the "oldie but a goodie" way to do things. I don't tend to use them myself because I never seem to make a clean bend (I never bought z-bend pliers either). It's a personal problem . I think the analogy with a broken toothpick is flawed, btw. Poke yourself with a straight 2-56 pushrod then one with a proper Z bend in it. You won't tell the difference. Better yet, push on both and see where it flexes or gives. You'll find it's not the Z that flexes, it's the unsupported length of rod.

Any way you are making a 90 bend, so it's going to weakened the same at each bend.

Sure, the wire will be weaker at the bend, but on a proper Z bend with proper wire, the Z is still far from the weakest link in the control system anyway. You're more likely to break a servo arm than a Z bend. I've sheared off any number of servo arms, so I know they aren't all that strong .

Of course if you are using heavy duty arms, metal servo gears, heavy duty metal control horns, etc it's a different story, but you don't see Z bends (or ez connectors) on those kinds of setups anyway .

I've never seen a properly done Z bend fail. I've seen all kinds of other failures though. If you can break it, I've broken it. Now, I have broken hardened wire while trying to bend it, but as John pointed out above, you shouldn't be Z-bending that kind of wire. A lot of imported ARFs come with hardened metric wire that will not take a bend with out fracturing.