Cracking Control Rods

I'd vote for better control rods. Unless those pliers have some pretty serious sharp edges your rods shouldn't break.

| I'm building a Phoenix Models Seabee pattern ARF, and I'm having problems | with the aileron control rods (push rods). My Hangar 9 z-bend pliers are | cracking the control rods when I try to bend them. | | Do I need to heat the control rods before bending them? Do I simply need to | replace the control rods with better quality, more flexible rods? Should I | try using different z-bend pliers?

I've never had control rods crack. Break after bending in the same place over and over (metal fatigue) sure, but never just ... crack.

Is it possible that they're not metal rods at all (piano wire), but instead carbon fiber or fiberglass? If so, then you don't use your Z bend tool at all, but instead you'll have to work something else out, like gluing to a clevis or gluing to a short metal rod which you can Z-bend.

Of course, you could probably replace them easily enough with something you're more familiar with.

Just a guess -- I've never seen this specific model. I assume that the instructions don't say anything?

From page 6 of the instruction manual:

"Installing the Aileron Linkages"

"9. With the aileron and aileron servo centered, carefully place a mark on the aileron pushrod wire where it crosses the hole in the the servo arm."

"10. Using pliers, carefully make a 90 degree bend down at the mark made. Cut off the excess wire, leaving about 4mm beyond the bend."

The pushrod wire supplied with the ARF seems brittle. The z-bend pliers cause the wire to crack at the corners of the bends.

Some of the wire for pushrods and such that is supplied in some of the ARF kits is rather soft...and breaks easily, as well...maybe some

1/16 K&S music wire as sold at your local hobby shop will do much better and will not snap when you put a z bend in with your z bend pliers. When,on occasion, I put together an ARF..if I find the wire in question to be soft or brittle, I replace it with music wire...no problem then Frank Schwartz

Ed, It's most likely due to cheap rods. Suggest you replace them.

Some of the less expensive ARFs use control rods that are too hard (usually black-colored) and they may break when bent in a Z-bend tool. Change out the rods for better ones or just use aless sharp 90-deg. bend and the supplied keepers.

Good flying, desmobob

Ed, first, you are not experiencing some voodoo or something. I have never been real thrilled with those Z pliers. I finally just took back my second pair and got my money back...the first pair broke at a bad weld.

I still use long-nose pliers for Z bends, but the rod had better be flexible. The only broken, professional rod I have broken were some DuBro and that was when I tried to bend the wire at the end of the threaded section. That area had been heat treated to give the threads more strength and that was where the wire broke.

The wire might be fine for long nose bending but crack with the stress of the Z pliers. All metal (well...most) has a minimum bend radius. The pliers, by design, are approaching the minimum bend radius of the supplied wire.

Oh, yeah...I don't use Z bends on rods anymore. I have gone back to an old fashion r/c design using a 90° bend and keeper.

Good luck...

Ken

As some of the others said , get new rods.....the Z bend pliars are not your problem. I've ran into this many times over the years ,especially on earlier ARF's with brittle black control rods.

Zbend pliars do work good. Been using them for over 20 years and never had a good rod such as Dubro , Sullivan , etc damaged by them.

Ken Day

Don't heat the rods - you will anneal them, making them way too soft. I like screw-on clevises and solder-on clevises. Z bends are for when, there are no other options.

Ken,

The wire broke at the threads because of the stress point created at the transition from the threads to the rod.

My only problem with Z-Bend pliars is that most of them are made for a different size of wire than the 2-56 stuff that most pushrods are made from.

Ed Cregger

They are too hard. Heat them to dull red and let them cool slowly.