Rudder Control on a 2.5 Meter Span Model
08-10-2021, 01:50 PM
#1
Thread Starter
Rudder Control on a 2.5 Meter Span Model
I have a 2.5 meter (8 feet 2 inch) span xtra model that I have been renovating over the winter months here in New Zealand. Its by far the largest aircraft that I have worked on and my question is about the best way to couple up the rudder. In a previous life the aircraft had two individual servos at the rear that worked alongside of the elevator servos to power the rudder which meant that there were four servos in total located down at the tail end. My thoughts are that it may be better to place the rudder servos more toward the center of the aircraft for balance and utiilise a Pull Pull wire system to operate the rudder. If so, can anyone recommend the ideal system to do this. I know that Du Bro do manufacture so called pull pull systems and one I have examined is a type called 881 which apparently is for larger aircraft. Would that suffice for a plane of this size? Any advice would be greatly appreciated.
Thank You
Paul Beck.
Thank You
Paul Beck.
08-19-2021, 03:24 PM
#3
Thread Starter
Thank you. I have managed to track down what I believe the aircraft type to be which is a Hanger 9 Extra 330L designed by Mike McConville and is a 97 inch wingspan model. I bought what was a pretty delapidated model requiring a lot of work including numerous repairs and being totally recovered which is nearly now all complete. The plane came fitted with two servos per aileron, two per elevator and two for the rudder which were JR 811 types and which were used to power most of its control surfaces. It was powered by a ZDZ 80cc engine. From what I have gleaned from experts here so far, it could perhaps be far better to now use single high powered servos to operate the flight controls and I think these JR servos are of the older type with an output torque of around 60oz-in. Still, that may be ok for this plane but I am certainly open to advice on ideal or better servo types etc and my radio system is a Futaba 14SG.
I did recently rig up the aircraft with the engine etc in place to do a rough CG check and found it to be quite close to the nominated position without the weight of two rudder servos in the tail. But again perhaps using just one powerful servo back there may have little effect on this and be easier than the pull pull system. All that needs done now is to sort out the flight control power, check the engine, complete covering and it should be ready.
Thank you for any advice.
I did recently rig up the aircraft with the engine etc in place to do a rough CG check and found it to be quite close to the nominated position without the weight of two rudder servos in the tail. But again perhaps using just one powerful servo back there may have little effect on this and be easier than the pull pull system. All that needs done now is to sort out the flight control power, check the engine, complete covering and it should be ready.
Thank you for any advice.
08-19-2021, 03:41 PM
#4
My Feedback: (17)
I would consider using the Dubro 883 for the rudder on that plane.
As far as servos, voltage will be the key here. I would run a 6.0v (5 cell nimh, or equivalent from a regulator), Hitec HS-645MG servos on all surfaces, and do the servos as the aircraft was intended. If you have more than 5 servos, consider running a second battery & switch. I fly the same transmitter, and would use a R6014HS reciever, so you can put every servo on its own channel, so you have control over centering & end point adjustment.
You may want to look into a power management system, something like SmartFly or Boomer, depending on how aggressive you are going to fly this aircraft.
Best of luck.
As far as servos, voltage will be the key here. I would run a 6.0v (5 cell nimh, or equivalent from a regulator), Hitec HS-645MG servos on all surfaces, and do the servos as the aircraft was intended. If you have more than 5 servos, consider running a second battery & switch. I fly the same transmitter, and would use a R6014HS reciever, so you can put every servo on its own channel, so you have control over centering & end point adjustment.
You may want to look into a power management system, something like SmartFly or Boomer, depending on how aggressive you are going to fly this aircraft.
Best of luck.
08-20-2021, 02:37 PM
#5
Thread Starter
Thanks. Just to clarify...you don't recommend using just one servo on each aileron given the power that some of these new servos have, but instead stay with the two servo option which does require a bit of fine tuning.
