Drive line failure on .15 rigger

[Andris Golts]

Im running an .15 rigger powered by a Picco .15 round side exhaust motor mounted on rubber isolated motor mounts Octura 5 mm to .125'' flex hex connector coupled to a Hughey .125 flex shaft sleeved in a teflon liner which runs in a brass stuffing box there is a 1/4 '' gap between the flex hex and the teflon tube i solder the last 1'' of the flex shaft that go "s in the flex hex with stay bright silver solder and i leave a 1/8'' gap between the strut and the drive dog running a x440 / 3blade prop the flex shaft breaks right at the flex hex i also checked the flex shaft to flex hex alignment which seem s to be alright. Any suggestions would be helpfull !

 

[TimD]

Maybe when you are soldering the end of the shaft it is getting too hot and causing the flex cable to temper. ???

I only solder the cut end just enough to hold the strands together. I try and do it as quickly as possible to keep the heat to a minimum.

I've always had success with Hughey shafts.

 

[TomMoorehouse]

sounds like your doing everything right..... TimD might have the most likely idea?

 

[Propjockey]

motor mounted on rubber isolated motor mounts

How much 'give' is in the rubber mounts?

If it has too much at speed, the vibration could be throwing the alignment off in pulses.

You might try cranking down the mounts to reduce the amount of engine movement.

 

[Ron Olson]

I never solder the end that goes into the flex hex and have yet to have a problem. I use Hughey cables myself as much as I can.

 

[Chris Wood]

check to see that your cable isn't rubbing inside the stuffing tube in the motor area.. i also counterbore the strut about a 1/4 so that will give you some clearence on the drive dog so it doesn't bind up on the strut because the cable accually shortens when running..

hope i helped

chris