Yesterday while flying my Midwest 300XS, one of the rudder pull-pull cables broke. I was using 135# test, nylon covered leader line. One end was secured at the rudder with a 4-40 eyelet, and the other end was looped through the servo arm and crimped. The servo arm was a heavy duty Du-Bro arm made of composite material. The cable wore through where it looped through the hole in the servo arm. The moral to this story is not to secure the cable as I did. I replaced the cable and put 4-40 eyelets at the servo end. This provides a somewhat less sharp edge where the cable wraps through the eyelet. This is a temporary fix as I need to come up with a more satisfactory method. The old method lasted for over a hundred flights. I think I will play with the idea of a pulley at the servo end. I haven't decided to keep the eyelets at the rudder end or to try and enlarge the eyelet surface where the cable attaches. My real problem is with my two larger models, a 1/3rd and a 35% scale models that have the same system as my Midwest. Any suggestions would be appreciated.
Cajuncharley

Get some of these Pull-Pull Wire Tensioners from SWB.

http://www.swbmfg.com/page5.html#wt

Nelson Hobbies has a real nifty way of securing cable without looping it.

try out Dons hobby shop system!! works great... the cables are Carbon-Kevlar!! good luck
Alex

All three of the previously mentioned ideas are good one....I am currently using the SWB method

shoot just go to the local hdwre store and get some 1/16 inch grage door opener cable it will fit in a 4-40 threaded couplers and just solder it in good and put a 4-40 kwiklink on it and never worry again

Heck, just get some 1/4" galvanized wire rope and use some Crosby clips to a steel door hinge.....

i have a 96 inch spook, 3 channel. have pull-pull on rudder and elevater. you can imagine force on rudder only ship this size. i use fishing snap swivels with standard pull wire and 1/16th copper tubing cut in 1/2 inch lentghs and crimped. havent had failure yet.