What material to use for non metalic pull-pull setup?
 

Can anyone suggest what material to use for non-metalic cables in a pull-pull system? I can't run my antenna inside the fuselage if I use metalic cable, as the antenna would end up only about 4" away from the pull-pull cables.

Are there any real disadvantages to using non-metalic cables?

Do non metalic cable setups require differnet hardware (i.e rigging couplers etc. than a metalic setup?

Thanks,

Mark D.

What material to use for non metalic pull-pull setup?
 

Kevlar thread. Not sure where to get it but that's going to be low stretch. For less demading applications you could probably get away with 1/2A Dacron controline thread. It's low stretch and strong compared to most stuff but the Kevlar would have it all beat hollow.

I think they even use Kevlar in place of steel cable for larger controline models now.

What material to use for non metalic pull-pull setup?
 

K & S markets Kevlar thread. The only problem is the ease with which it shreds when you catch it on a sharp corner. Once you get it in place, it lasts forever. The other option is "Spiderwire" fishing line.

Les

What material to use for non metalic pull-pull setup?
 

The antenna in my Balsa USA Eindecker shares the interior space with 6 steel pull-pull cables.
I have several planes with the antenna and pull-pulls in the same space.
I use the DuBro pull-pull kits, and also .012" control-line flying wires.
If you're really antsy, Sullivan makes a Kevlar pull-pull setup, which I have also used.
I set these up with the coupler (makes no difference which type you use) at the surface rigged to permit taking up as much slack as possible before flying (maximum number of threads available to tighten the wire), as the flying loads will "bed" the cable run better than you can do it before flight.

What material to use for non metalic pull-pull setup?
 

I second the Spyderwire fishing line! Sierra and Wahoo have trouble with it as well!
You will need the tensioner as it is impossible to tie to exact length! 50# test you can put through the eye of a medium/small standard sewing needle. A small polyethelene tube at any abrasion points for insurance.
mikenlapaz :)

non matalic material for pull-pull
 

Ok., it seems Spiderwire is a good choice. Now how do you connect it to the rudder servo? Straight to the arm, or do you use some type of tiller (idler arm). This will be on a 1000 Sq. in plane and the calculated maximum load will be about 60 oz of torque. Also, do you use some type of coupler on the servo end, or just loop the thread through the servo arm directly?

Thanks,


MarkD

What material to use for non metalic pull-pull setup?
 

Spyder is stronger than steel of equal diameter. The package shows some good knots to use. Putting the spyder into perspective: Material:100% Spectra 50# test .011" diameter

IMO something like the Proctor turnbuckles with clevis (Tower)would be a good item to investigate. It has the eye for attaching the Spyder and the clevis (if sized right would give a thru pin attachment to either the control surface or servo.

Multiple wraps around your attach points will distribute the pressure and wear abrasion at the contact point.

I'm new to RC so hopefully others will share on other connector options.
mikenlapaz

What material to use for non metalic pull-pull setup?
 

While you are in the fishing department looking for Spyder wire be sure to look at swivel connectors, etc. Also crimping connectors.

Pull-pull wires don't have to be tight, just snug.

What material to use for non metalic pull-pull setup?
 

IMO do not try to crimp the spyderwire. A snap swivel would be an easy option for connection to a control horn or arm whatever they are called!

What material to use for non metalic pull-pull setup?
 

Instead of spyderwire I use powerpro fishing line. Also used the K&S kevlar thread, and the kevlar pullpull mentioned in an earlier message. No stretch, stronger than anything.

Just don't hit the power-pro with a heat gun because it melts. . Kevlar will not melt.

I tie the line directly thru the hole in the servo horn. Use a fisherman's knot, and slide the knot to snug the line. then lock the knot with some thin CA. On the control surface end, I tie the line to a 2-56 eyebolt screwed into the clevis. This provides some adjustment for later.

I have used this on rudders, elevators, split elevators, and water rudders (floatplane) with never a problem. The only time I ever got slack was using a 4-40 stud for a rudder horn, and the rod bent and relieved some tension. Never broke a string yet, and I've been using this for 6+ years.

line tension adjust w/bike spokes
 

take a bike spoke, drill a #55 hole in square end of the adjuster nut to tie the line thru, cut spoke to length for attachment to either servo and/or control horn with Z bend. You end up with 1/4" of adjustment on each end. Once adjusted to desired tension, seal/lock the threads with CA!
Having never used CA, but it should work like Locktite. Yep, a newbie all I know about your hobby supplies is what I've read so far! Comments please, trying to learn.
mikenlapaz

What material to use for non metalic pull-pull setup?
 

I have used bike spokes, too. The hub end works better than a z-bend, and the threaded end is, as you say, nicely adjustable.
If using the galvanized type: remove the zinc plating before soldering. It's toxic and keeps the solder from sticking.

What material to use for non metalic pull-pull setup?
 

Where do you find 2-56 eye-bolts?

What material to use for non metalic pull-pull setup?
 

>>Where do you find 2-56 eye-bolts?<<

It's a standard Du-Bro part.

I just can't stand those drilled 2-56 studs that come with pullpull kits. It makes the cable turn way too tight, and pulling over the edge of the hole can't be good for the cable.

What material to use for non metalic pull-pull setup?
 

Okay Jim:
I've never used a pull-pull kit. In all honesty I just use fishing line and pull it up snug and tie it but that is for 1/2A models.
A little adjustment option would be nice.

Don Coombs
Somewhere near Dunnelllon (FL).
'Til the weather gets warm up north...