Lately I've converted most of my pull pull systems to pushrods, but on my SemiNoll with dual elevators it's more difficult. I've been using Spider Wire, but have been having a lot of trouble keeping it tight enough. Either it's stretching or the foam is contracting in our colder weather.

Suggestions/comments appreciated.

Azarr

Azarr,

On the Spider Wire, with normal single elevator, you can run your two lines up through the bottom of the servo horn, then wrap around the servo arm screw clockwise. Then all you need to do, is tighten the screw when the cables loosen.

Seth

Gee Seth, that sure sounds familiar...

Azarr I think I showed you that pull-pull setup on one of my planes at KIEF. I have done the exact same thing on a Seminoll with split elevators and the tiny little D47 servo screw and it still worked fine.

Of course, ideally we'd find some line that doesn't need tightening and still doesn't stretch under load...

RJ

Thanks Seth & RJ, is there different types of spider wire? Mine is stretched out to a ridiculous amount. i.e. on the rudder, it's so loose I can almost reach 3/4 of the way up to the top of the fuselage. It's definitely not slipping, I can't force it to slip. Mine is fixed at both ends, I didn't leave any adjustment, but it's so loose there would be no way to adjust it anyways. We've got a huge fishing supply store in Dayton, I'm going to check it out next week and see what they have to say.

Azarr

its a tedious job but i strip the kevlar strands that are about every six inces apart in my carbon fiber cloth and use them, havent had trouble since, doesnt seem to load the hinges as much either

Originally Posted by Azarr

Thanks Seth & RJ, is there different types of spider wire? Mine is stretched out to a ridiculous amount. i.e. on the rudder, it's so loose I can almost reach 3/4 of the way up to the top of the fuselage. It's definitely not slipping, I can't force it to slip. Mine is fixed at both ends, I didn't leave any adjustment, but it's so loose there would be no way to adjust it anyways. We've got a huge fishing supply store in Dayton, I'm going to check it out next week and see what they have to say.

Azarr

Let me know if you find anything good there Azarr! I might have to run over and pick some up myself!

Seth

Originally Posted by hpapilot

Gee Seth, that sure sounds familiar...

Azarr I think I showed you that pull-pull setup on one of my planes at KIEF. I have done the exact same thing on a Seminoll with split elevators and the tiny little D47 servo screw and it still worked fine.

Of course, ideally we'd find some line that doesn't need tightening and still doesn't stretch under load...

RJ

And yes, I know...

I don't use spider wire though so...I just figured I'd tell him how you do it.

Hi,

I'm using wire used for kites. They have improved now to almost no stretching material. It's the smallest size they have and it's something like 0,5 mm thick. Weight is less than a gram on one meter. I use "alu-tubes" that I press with a wire to keep it holding. It doesn't move and doesn't stretch at all. If you want I can post a photo.


Regards
ruud

www.f3p.eu

ive found that if you need to tighten the lines a little on a model you can remove the horn from the servo and carefull twist it and the lines will shorten up with only 7-10 twists. storing models with the surface deflected slightly also seems to stop them from stretching out as much.

Originally Posted by Ruud_NL

Hi,

I'm using wire used for kites. They have improved now to almost no stretching material. It's the smallest size they have and it's something like 0,5 mm thick. Weight is less than a gram on one meter. I use "alu-tubes" that I press with a wire to keep it holding. It doesn't move and doesn't stretch at all. If you want I can post a photo.


Regards
ruud

www.f3p.eu

ruud, are you using a Spectra material?

Azarr

I have been using regular fishing line for years with good results. 17 lb test stretches enough to move with the airframe and is still highly effective. I unfortunately don't have the pleasure of tightening my pull pull lines every day....



Devin McGrath

Aww man Devin, you're missing out on the fun! When you're lucky, you get to tighten them 2 or 3 times a day...

Originally Posted by Azarr

ruud, are you using a Spectra material?

Azarr

Azarr,

Is Spectra the product or the brand?
The product I use is called Aramide (it's kevlar kind). It has a stretchratio of 3% max. It's a kind of yellow stuff.

Regards
Ruud

www.f3p.eu

Originally Posted by Ruud_NL

Azarr,

Is Spectra the product or the brand?
The product I use is called Aramide (it's kevlar kind). It has a stretchratio of 3% max. It's a kind of yellow stuff.

Regards
Ruud

www.f3p.eu

Spectra is the product, I think it's a polymere of some sort, just as aramide is kevlar. I'm going to try kevlar next, I haven't been able to get my hands on any, but have some on the way.

Thanks for your input,

Azarr

This outfit seems to have almost anything you could ask for in thread...

www.thethreadexchange.com

I got a spool of the #46 Kevlar, but I haven't used it yet

Dave