aviast
Well-Known Member
Hello,
The article "Algebra and the Elevator Control System" in the latest Kitplanes has prompted me to post this thread... I've long wondered how to calculate the forces on a control surface. Are there any good references available on the internet?
The Kitplanes article starts with the maximum stick force permitted by the FARs (167 pounds) and calculates the forces through the system to the elevator where that stick force results in an elevator moment of 1096 inch pounds of force. But how much force do you need to displace the elevator by (in this case) the maximum 30 degree deflection? (for a particular speed).
The reason I've wanted to be able to make this calculation is to calculate the forces to deploy the speedbrake on the Thatcher CX5.
This speedbrake is actuated by a Honda window winder mechanism:
Amazon.com: Dorman 741-565 Honda Civic Rear Passenger Side Window Regulator with Motor: Automotive
I don't know how much torque that motor produces, but I assume it's not a massively powerful unit. My ultimate goal is to design a drop-in replacement mechanism to manually actuate the speedbrake (ie. remove the window winder) with a similar cockpit control to a glider/motorglider speedbrake control.
The article "Algebra and the Elevator Control System" in the latest Kitplanes has prompted me to post this thread... I've long wondered how to calculate the forces on a control surface. Are there any good references available on the internet?
The Kitplanes article starts with the maximum stick force permitted by the FARs (167 pounds) and calculates the forces through the system to the elevator where that stick force results in an elevator moment of 1096 inch pounds of force. But how much force do you need to displace the elevator by (in this case) the maximum 30 degree deflection? (for a particular speed).
The reason I've wanted to be able to make this calculation is to calculate the forces to deploy the speedbrake on the Thatcher CX5.
This speedbrake is actuated by a Honda window winder mechanism:
Amazon.com: Dorman 741-565 Honda Civic Rear Passenger Side Window Regulator with Motor: Automotive
I don't know how much torque that motor produces, but I assume it's not a massively powerful unit. My ultimate goal is to design a drop-in replacement mechanism to manually actuate the speedbrake (ie. remove the window winder) with a similar cockpit control to a glider/motorglider speedbrake control.
