degrees throw in the elevator
03-29-2004 | 12:01 AM
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From: Coquitlam,
BC, CANADA
degrees throw in the elevator
I am just finishing up my four star 40. I was wondering how much degrees throw in the elevator I should have. I am getting 10o degrees both up and down. That seems low to me. If it is low how can I get more degrees throw in the elevator? Positioning of the horn or is it all Servo are length?
Thanks
Thanks
03-29-2004 | 01:21 AM
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From: Craig, CO
RE: degrees throw in the elevator
The instruction book will list the throws for low rate and high rate. Throws are shown as amount of deflection at the widest part of the surface. (in inches either way from neutral).
For most planes of this type, a good starting point is:
Ailerons 3/8" low rate, 1/2" high rate
Elevator 3/8" low rate, 1/2" high rate
Rudder 3/4" low rate, 1" high rate
But....you should go with the factory recommendations.
These throws are assuming you have the plane balanced at the recommended CG. If the plane is slightly nose heavy, you can increase the elevator throw a little, but if it balances at the AFT CG maximum, you should DECREASE the throw on the elevator to 5/16" or even 1/4". Too much elevator on a tail heavy plane is disaster.
To increase throws, use the outermost hole on servo arm and innermost hole on the horn.
To decrease throws, use the innermost hole on servo arm and outermost hole on the horn.
You didn't say if this is your first aileron/low wing plane, but I might add something. If you used the kit ailerons horns as supplied, you will either have the same up and down throw, or you might have more down than up. The latter is not good, as you will have "adverse yaw". For instance, if you try to bank left, the right aileron, being more down than the left is up, will tend to yaw the plane to the right. With sufficient dihedral, the plane might even turn right when you wanted to go left, especially if flying slow at a high angle of attack. The right wing could even stall, causing nasty things to happen. If you have this condition, bend the vertical aileron horn arms (using 2 sets of pliers) back (toward the trailing edge), and lengthen the push rods. You can achieve the same effect by making a special servo arm/wheel that hooks the aileron pushrod aft of the servo wheel center line. If this confuses you, seek the help of a local flier experienced with "differential" ailerons. This is more than you asked for, but I have seen some nice planes ruined because of this.
BO
For most planes of this type, a good starting point is:
Ailerons 3/8" low rate, 1/2" high rate
Elevator 3/8" low rate, 1/2" high rate
Rudder 3/4" low rate, 1" high rate
But....you should go with the factory recommendations.
These throws are assuming you have the plane balanced at the recommended CG. If the plane is slightly nose heavy, you can increase the elevator throw a little, but if it balances at the AFT CG maximum, you should DECREASE the throw on the elevator to 5/16" or even 1/4". Too much elevator on a tail heavy plane is disaster.
To increase throws, use the outermost hole on servo arm and innermost hole on the horn.
To decrease throws, use the innermost hole on servo arm and outermost hole on the horn.
You didn't say if this is your first aileron/low wing plane, but I might add something. If you used the kit ailerons horns as supplied, you will either have the same up and down throw, or you might have more down than up. The latter is not good, as you will have "adverse yaw". For instance, if you try to bank left, the right aileron, being more down than the left is up, will tend to yaw the plane to the right. With sufficient dihedral, the plane might even turn right when you wanted to go left, especially if flying slow at a high angle of attack. The right wing could even stall, causing nasty things to happen. If you have this condition, bend the vertical aileron horn arms (using 2 sets of pliers) back (toward the trailing edge), and lengthen the push rods. You can achieve the same effect by making a special servo arm/wheel that hooks the aileron pushrod aft of the servo wheel center line. If this confuses you, seek the help of a local flier experienced with "differential" ailerons. This is more than you asked for, but I have seen some nice planes ruined because of this.
BO
