Cat,pumptato-cat wrote: ↑February 8th, 2023, 3:35 pm Hey all, anyone using a Freedom Flight torque meter? I have one and the needle always starts in a different place when I wind. It seems to center around 0.03oz. I wouldn't care normally but I've been getting inconsistent flight heights(for anyone with access to my flight log, I will update winding logs later tonight).
Here's an example:
Rubber: 0.094", 1.95g
Flight 1: 1.1oz max torque, 0.49oz launch torque, 115 winds 1:15, 17 dewinds. Flight height(Estimated using a laser pointer) around 23ft?
Flight 2: same settings except 116 winds, less dewinds I think? Details in log. 13ft. Absolutely no clue what happened there
Flight 3: same settings, still climbing very strong around 23ft, hit ceiling and crashed.
What's going on? I've noticed as the rubber stretches after the first run, it takes less dewinds or more winds to reach the same torque value. That seems normal but I also think the torque meter itself is inconsistent--the needle never starts at 0oz. I tried tilting the meter face to match with the needle at 0oz for starting, but the needle keeps shifting to the right and I don't want to have the meter face at a 90deg angle.
There's a wire hook that hooks onto a screw at the back-it is bent slightly at an angle. Is that a problem? (will provide pictures if I have time)
Context: I fly in a small dome--peak height 30ft, but seats(Auditorium) and curved ceiling cut flight area down to around 23ft or so. Sometimes there are slight air currents blowing upwards.
I'll add to what Coach Chuck noted. Other factors that can affect climb height. A bad launch where the airplane dips for a foot or so shortly after launch can remove up to 3-4 ft from overall climb height. It's like the airplane has to expend lots of power to overcome the dip and get climbing again. If the motor winding was not smooth and there are knot chains or knot "clumps" these don't release turns smoothly and climb height will be 3-8 ft less, depending upon how bad the clumps are. Air currents can cut down climb height even if they only cause the wing to rock occasionally. The airplane expends power recovering from each of these wobbles/rocking.
Also, if you're right on the margin of a workable rubber density the second flight might just not have the correct power curve (I think that this is the most likely issue) and you would need possibly another .002 - .004 g/in density. For example, if your current motor is .060 g/in, you might need .062 or .064 g/in; test it and see. Don't focus on the first use of the motor when testing. Look at the whole series of flights on each new motor (a good series for us will be six or seven flights, each with a few more max turns and gradually pushing higher and higher max torque). With careful winding procedures, we've gotten amazing flight on even the 8th or 9th use of a motor this year (this is rare; we'd never compete with a motor used this many times).
You've probably already seen that the first use of a rubber motor always climbs higher than later uses if wound the same. We consider the first use of a motor "throw away data". We'll never compete on the first use of a motor (1st use is also almost always lower duration and turns), so we don't push it and usually go with slightly less launch torque to just get it up to about 80% of ceiling height. The second use we start pushing the turn count and max torque and focus on launch torque to try to hit particular climb heights.
Brian T
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