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Old Apr 04, 2007, 01:46 AM
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Park Jet Guru
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Seattle, WA
Joined Jun 2002
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Flight Controls

There are many ways the flight controls of this model could be set up. To actuate everything (stabilators, flaperons, rudders, canard, thrust vectoring, throttles) would require 9 channels and up to 8 servos! But on the other hand, this model could be flown just fine using tailerons only, with 3 channels and 2 servos. There are many pros and cons for all the different setups, but I chose to go with a middle ground setup on my model. It uses tailerons, rudder, thrust vectoring, and twin throttles, for 7 channels and 5 servos. It does not have flaperons or a moving canard. My rationale for this is:

* Flaperons aren't needed because this model already rolls well at high speed with the tailerons and well at low speed with the thrust vectoring.

* After giving it a lot of thought, I decided that a fixed non-movable canard would be the best way to go on this model. Although the real Su-37 has a moving canard, it isn't linked directly to the stabilators. It's actively controlled by a computer to provide high alpha stability and can move either with or against the stabilators, whichever is required. On an RC model we don't have that luxury and must slave it directly to the stabilators one way or the other. And I decided that simply leaving the canard fixed would cause it to stall early and reduce or eliminate the pitch-up that is common to highly swept wings with strakes. Flight testing has verified that this setup works as intended—this model has no high alpha pitch-up (like on the F/A-18 park jet).

As usual, rudder is optional on this park jet. It's nice to have but not required. I originally built this model without rudders thinking the yaw TV would be enough, but flight tests showed that the yaw TV response was so slow that it really wasn't effective for normal maneuvering. So I ended up retrofitting rudders into the model.

Attached is a chart below that summarizes all the channel assignments and mixes I used for my model. Note that I used all 7 channels of my Berg 7P receiver and used all 7 programmable mixes on my Futaba 9CA transmitter! This is not a simple model to set up, but once done it's easy to fly since everything is controlled automatically. All I have to do is flick a switch to turn the TV on or off! If you want to build this model but don't have a fancy transmitter, you can just build the mechanically slaved TV version. That eliminates the need for all the programmable mixes and 2 additional channels.
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Last edited by jetset44; Apr 05, 2007 at 01:44 PM.
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