• Torque/Counterweight arms RSS Feed

    by Published on 10/04/2002 04:46 AM
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    2. b Chapter 3 - Canard/Elevator

    There is simply a ton of work to do on the canard and elevators. This section talks about the center hinge are, but as you can see above we lined this out and installed it during Head Start week with the rest. Then we measured from the center hinge out 20 1/2" onto both elevators and trimmed the torque tubes to this length. Then the concentric torque tubes are installed inside the elevator torque tubes. The concentric torque alignment is checked, and then a 3/16" hole is drilled through it and countersunk for a MS24694S-59 (I actually had to order longer screws from AS&S) and locking nut.

    Then the inboard counterweights can be installed on the center hinge arm. Note that my instructions and packaging didn't make it too clear that each outboard side of this arm gets 1 and 1/2 of the squared off counterweights with foremost holes getting a common 3 1/2" screw and space to hold them together. A call to the factory quickly clears this up.

    On the outboard side of the elevators you get to use your creative thinking skills. Here you have multiple independent variables which are all important. You need to cut a notch in the canard for the counterweight to rest in all of the way to the inner skin (5 1/4" long, 1 1/4" wide), which will get fine BID glass later. You also need to cut just enough of the torque tube back to allow the thickness of the arm to rest flush once that notch accepts the counterweight. Except that you can't put the counterweight arm in yet, because it's so bloody tight of a fit that it will never come back out, and it's CRITICALLY important that the angle of the counterweight just stops the elevator travel at 28 degrees Down Elevator. Good luck. I fiddled and fitted and cajoled everything pretty close, then once I had the counterweights in still had to give it a few love taps to align things properly. Might be a better way, but it didn't come to me. Need to sign up for those patience lessons, perhaps.
    Mounting the elevator canard inboard weight to prevent aerodynamic flutter
    Canard Inboard Counterweight (only 1 weight here)
    Cutting the outer canard counter weight recess pockets so that the outer counter weight stops control movement on the upper (inner) skin of the canard.
    Canard Outboard Counter-weight Recess

    Offset Torque Tubes

    Counter-Weights

    Center Weight

    Once the weights are positioned, they get the same screw treatment as the concentric torque tubes. Then the elevators need to be finished off, and as I have the fast-build Brazilian elevators I need to cut some foam to fill the open ends of the elevators with, micro, and BID.

    Counter Weight Fairing

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