I'm working on a plan for an electric flyer with no control mechanisims showing. I've not seen them on full scale aircraft since 1920 and wonder why we don't "keep it inside" on our models. I'd like to try a method with Pull-Pull controls. What do you guys use to connect those servo arms to the control horns? Fish Line? Monofiliment line? I can't think of anything lighter or stronger.

Try a fishing line called "Spiderwire". It's similar to kevlar thread. Very, very strong and light. Don't use monofilament. It stretches.
Check the Du-Bro and Sullivan websites. They sell ready made kits for pull pull mechanisms that have all needed hardware. Once you see how they do it, it's easy to figure out how to do it on your own using swivels and such from fishing tackle.

Thanks, Greg! You gave me a suggestion and a source for education on the subject.
Bill

One reson we don't hide all control mechanizms on .40 size and smaller planes is we need the leverage of the longer control horns.

While the pull-pull system doesn't need quite as large a control horn (pull is more positive than push) You'll still have an interresting time getting the lines rigged evenly. The smaller the control horns and the smaller the servo output arm, the larger a deflection a TINY mismatch in cable length will make. (and the less room for error in lining up the horns with the hinge-line)

The alignment of the pull pull lines is something I forgot about. I use a computerized radio (JR XF421ex) and alignment with control horns is apiece of cake. If I can make it go, I sure will have to hook them up with both in perfect, centered neutral position. THANKS![img]i/expressions/face-icon-small-smile.gif[/img]

The pull/pull cables must not stretch under any circumstances. The spider wire fishing line I found was unsuitable. There is a web site called "intothewind.com" for kite flyers. They have various types of Spectra line at a very reasonable price. You can get it in different strengths. I Use 50#. It comes in rolls of different lengths.
I buy the 50# in a 200' roll. You can build a lot of pull/pull setups with that much.

I'm rigging my first 40 size plane with a pull-pull rudder system. I've done a park flyer.

I was planning to use nylon coated stainless steel fishing leader. Now I'm reading all sorts of stuff about spiderwire and kevlar. What are your insights on leader wire?

Thanks Roodester

Coated stainless leader should work fine. You'll need to remove the coating at the areas where you are making the actual connections, as it will quickly wear through anyway and that would loosen up the control system.

The stainless leader gets used by some CL flyers for insulated flying lines (allows sending a digital signal to a "RX" in the plane for up to 8 added functions with just 2 lines) and has to put up with some rigorous testing and stretch would be a BIG problem for the CL flyers.