Thread: Build Log Pike Precision - Baudis RDS
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Old Feb 03, 2013, 07:13 AM
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Joined Mar 2009
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optimized linkage should use all servo trow.

Originally Posted by ttraver View Post
To answer your question on the trimming, since this coupler doesn't have a particular position, you didn't have to worry about doing any of the servo zeroing with the coupler on. I just zeroed everything and left it on before I connected it while in the pocket.

Like in a conventional linkage, an RDS should ideally use all the available throw of the servo to get the best mechanical advantage. Since the flaps move asymmetrically (much more down then up), you have to digitally offset the flap servos before you connect the couplers. Or in other words, if the servos are neutral on the transmitter, the flaps should already be deployed some 30 to 40 degrees. You use the subtrim to bring them back to the desired camber position in every flight mode, I use all the available subtrim there is (maximum servo offset).

This makes sure that you use all the available servo throw. It is mechanically better (higher resolution, less slop, better use of available servo torque)

If you don't do that and you still get enough flap deflection, then the RDS geometry is not ideal. You essentially throw away almost half the servo throw. It is like a conventional linkage with a too small surface horn and a too large servo horn, which does not use all servo throw.
In RDS terms, the wiper angle is too large and could be reduced for an optimal linkage

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Last edited by RetoF3X; Feb 04, 2013 at 05:57 AM.
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