Servo push rod types
#1
Thread Starter
Join Date: Jul 2004
Location: Cape Town, SOUTH AFRICA
Posts: 579
Likes: 0
Received 0 Likes
on
0 Posts
Servo push rod types
I have sullivan Gold'n' Rods installed in a plane and had the trims neutral with neutral control surface deflection (rudder and elevator).
Yesterday was a warmer day than recent days have been and when I took off the plane climbed steeply. It took almost all of the available downtrim to maintain level flight, the rudder trim also had to be significantly adjusted.
I have put this down to the expansion of the push rod inner with the higher ambient temperature.
I propose to remove the yellow inner rod and replace it with a length of threaded metal rod inside the red sleeve.
Will this remedy the problem?
Daily temperature diference morning to afternoon can be quite significant at times and I expect this will be an ongoing issue.
Yesterday was a warmer day than recent days have been and when I took off the plane climbed steeply. It took almost all of the available downtrim to maintain level flight, the rudder trim also had to be significantly adjusted.
I have put this down to the expansion of the push rod inner with the higher ambient temperature.
I propose to remove the yellow inner rod and replace it with a length of threaded metal rod inside the red sleeve.
Will this remedy the problem?
Daily temperature diference morning to afternoon can be quite significant at times and I expect this will be an ongoing issue.
#2
Senior Member
My Feedback: (9)
RE: Servo push rod types
I never liked the red golden rods ,thought they were too flexable .Used to build them into the wings & make a curve with them . I have never had trouble with the blue colored ones,much stiffer . I think you may have had a bending problem from the heat . Metal rods might help but they may expand also . Good luck , MAX H.
#4
Senior Member
Join Date: Oct 2002
Location: Philadelphia,
PA
Posts: 2,065
Likes: 0
Received 0 Likes
on
0 Posts
RE: Servo push rod types
It is humidity as well as heat that causes changes in nylon rods. You can solve the problem with Sullivan carbon-filled pushrods- they are absolutely stable. If you want to use metal pushrods don't install a thick,heavy threaded rod, but use a smaller diameter music wire rod with soldered connectors at the ends. The plastic outer tube will provide the rigidity.