rnrick1

I need some adice on different techniques on conecting the push rod to the servo. Which is better to use: Quick connects or Z-bends. Is there any slop with Z-bends? Which is the best Z-Bend tool?

flap

Z-bends are definately the most reliable form of connection.
However, unless you are superbuilder, youll need some form of adjustment @ the other end, controll surface, throttle, ect..
Here I like soldered clevices.
If you dont want to go that route. Nylon or Metal clevices which screw onto the end of the threded pushrod work nicely and give you a fair amount of travel for adjustment, just be sure you cut a small peice of fuel line 1/4" or so and slide it on the pushrod before connecting, after making the connection, slide the fuel line over the snap together end to prevent it from coming apart, DONT leave this step out.

Have a nice day
Roger

Vince

My Feedback: (1)

Z bends are the way to go. I like the KISS method. The less hardware you employ, the better.

Vince

ilikeplanes

At one time, I thought Z bend were fool proof. I never used them because of the adjustably issue though. My last plane had Z bends and I discovered a flaw with this system. If the bend is made such that the wire can slide back and forth, or up and down in the control horn hole, the wire will tend to wear the hole and create excessive clearance. My real life experience with this ended my Z bend days. From now on, it's clevises with locks (Sullivan) and through screw ball joints.

RCKen

My Feedback: (9)

It depends on the control you are connecting. non-critical throws can use quick connect. By non-critical I mean throttle and rudder, the controls you can still land without if you lose them. but for the critical controls (elevator and ailerons) always used z-bends or soldered clevises. My real life experience taught me this lesson all to well. During a trim flight after re-covering my Midwest Super Hots the elevator became all but unusable. all I had was just a little bit of up elevator control left, with no down control what so ever. I did manage to get it back on the ground, but not without leaving a brown streak down the back of my legs (if you know what I mean). after landing I found my problem. the quick connect I had used for the elevator had vibrated loose allowing the control rod to slip in the connector. the only thing that saved me (and gave me the little bit of up control I had left) was a blob of epoxy that had fallen on the end of control rod and was catching on the quick connect whenever I applied up elevator. that was enough to convince me. no more quick connects on critical throws for me. always use z-bends or soldered clevises. you can always leave adjustment at the other end with a screw on clevis.

hope this helps

ProfLooney

Personally I hate Z bends due to adjustments and havent had too bad of prob with clevices if properly installed. What I use on all my planes which are always 100" ws or more is ball joints. Never had a problem yet and never had a problem with slop or wear.

Joe

pinball-RCU

On the issue of slop with Z-bends: I don't drill out the servo holes. Instead, I sharpen the end of the push rod, and kind of twist it into the servo hole so it's nice and tight.

I do recommend ez-connectors for throttle, but even there you have to check them occassionally. Last time I was out flying I lost throttle control because an EZ connector came loose. Do you know how long a .46 will run half-throttle on 8 oz of fuel?

Personally, for the control surfaces, I've settled on a Z-bend at the servo end, and a high-quality screw on clevis at the control surface.

BingoFlyer

While I was the safety inspector for our club (all new planes had to be inspected) the club did not approve E-Z connectors except for the throttle.

I used Z-bend and threaded clevis for years with no problems, I now use ball connectors for the ease of adjustment, no slop, and no binding if the angle is not just right.

Vince

My Feedback: (1)

On the issue of adjustability with Z bends, make the control end adjustable, not the Z bend end.

Vince

rajul

My Feedback: (58)

I've used dubro and gp ez connectors on my 46 trainers with no issues so far. But I have heard of some inferior ez connectors provided in kits from Vietnam and elsewhere that do break or slip off. Just my 2c........

Texas 3D

My Feedback: (16)

Instead of Z bend just do a U bend ! Much easier, and no worries about slipping out . Gives you also a vertical adjustment instead of only a horizontal like with the Z bend, which prevents to much load on the servo. Just my $0.02

Azcat59

I put a 90 degree bend in the rod at the servo end. Run it up through the servo, and put a 1/16" wheel collar on it. Drill it out with a 5/64 drill if you are using pushrod material thicker than 1/16 piano wire. "Will it hold?" guys ask..... It holds your tail wheels on under a lot more stress doesn't it? At the other end, I usually use the black Hayes klevis with the steel pin. (Used to be Kraft-Hayes). This has worked well for me for many moons....

Clair Sieverling

TerrellFlyer

at the servo end I use Z bend,U bend or L bend with plastic holder,as far as bending tools I prefer two pair of electrictians needle nose plairs,have used other tools but the bends were squared and wore the hole larger with movement.
Have a goodun,John.

AQ500

I'm not saying Z-bends are bad. I've seen two planes go in because the Z-bend pliers used put such a tight bend in the wire that it failed mid-flight. Just a warning.

I use EZ connectors on throttle and nosewheel for adjustment. I lost an airplane to an EZ connector on the elevator the first year I was flying. That was before the days of the new metal retainer. The nylon retainer slipped off and the rest was history. I mostly use L bends and the fastlink pushrod keepers. That is a reliable connection and if you need to remove the pushrod for whatever reason, you don't have to remove the servo arm. I do use Z-bends every once in a while.

I say if it works and will be reliable, do it!

ReallyUglyStick

My Feedback: (5)

to take the slop out of z-bends, slide about 1/2" of fuel tubing over the servo control arm, then poke the z-bend through the tubing on both sides. it makes the z-bend nice and tight. this works great if you make "less-than-perfect" z-bends.

KenChoo

Hi all...got a follow up question. I know that over time a Z-bend can wear out the hole in the servo output arm so that slop develops in the control. I wondered how the L-bend with plastic retainer compairs? I would imagine it wears out the hole as well... For that matter, why doesn't the sullivan clevis w/lock or ball joints do that?

Cheers,
Ken

TerrellFlyer

only time I've had any wear problem is when using z bend plairs,as stated on post # 13 I no longer use them.

dhable

My Feedback: (3)

I've been flying RC for 9 years, and have used Great Planes EZ connectors on every servo of every airplane I have built. I have never had a failure.

I fly .60-sized airplanes, Top Flite fighters for the most part.

I use them because they are the easiest to adjust. I tighten the bejeebies out of them, and check them before each flight and have yet to experience any ez-connector related failure. In fact, I've piled a few in (my fault) and the connectors held even after the jolt of a nose in crash.

rajul

My Feedback: (58)

Hi dhable, are you referring to the gp screw lock connector (made of brass with a screw for securing pushrod) or the fastlink (made of nylon and snaps into the pushrod) ? Dubro's ez connector is equivalent to the gp screw-lock connector.

dhable

My Feedback: (3)

I mean the Great Planes screw lock connectors. Actually, mine are hex bolts, not screws. They fit into a brass bushing which secures to the servo arm with a nylon or metal lock washer. The contol rod is run through a hole in the brass fitting, then clamped with the hex head bolt.

SoppyJoe

My Feedback: (59)

You want to be careful when using z-bend pliers on some the the push rods that come with many of the ARF kits out there. Often the metal is real brittle and the pliers can crack the rod.

Joey.

rick121x

I have used Z bends and clevis's for many years in large gliders and in my powered R/C's. ...never a single problem.

I always anneal the push rod wire with a small torch to soften it before I do the Z bend, thereby avoiding the overstress weakening problem due to too sharp a bend. I believe that the very sharp bend is a critical problem.

Anneal by heating to dull red color, and then using the torch less and less to allow the wire to cool slowly - say, 20 or 30 seconds.

If for some reason you didn't trust the strength of annealed metal, you could reharden it by heating to a dull red color and cooling by dipping in oil. (Hardening has not been necesary for me... execpt when I do landing gears)

Richard Ranney

$ircra$halot

I've known people to use all different methods with success. I prefer ball links at both ends my self, but have been known to use z-bends, or kwick links for throttle or nose wheel applications. The moral of the story is like ( I think it's Will Geer) that says check your blood sugar, check it often. The same applies to every aspect of model airplanes, check them top to bottom front to back, Don't forget the transmitter, IE right model loaded into the memory, and battery condition. Always happy to help if I can Garry

fop26

Me thinks your thinking of Wilford Brimley!

$ircra$halot

Yeah Wilford that's the ticket yeah, yeah