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Old Nov 09, 2012, 06:15 PM
SteveM is offline
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Joined Dec 2002
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Got a Smartphone? - You've got an Incidence Meter!!

Search apps for "Clinometer" or "Inclinometer".
My son was messing round with his on his phone, and noticed that it showed a reading to within 0.1 degree.
Argument developed, as I doubted that the phone sensors would be good enough to ensure sufficient consistency/ wrong could I be!!
I downloaded it, placed phone on granite kitchen worktop, let it settle and took a reading.
took another the next day....same to within 0.1deg.
Despite this, if checked against set square, it was found to be (albeit reproducably) 0.9 degrees out, over the 90deg rotation.
Then noticed that aswell as the free app version, there was a chargeable upgrade (50p), which allowed calibration, and the ability to zero at any angle.
Did this, followed the instructions and, sure enough, could get it to scale perfectly between 0-90deg.
Cunning plan.......carefully marked out a sheet of 1/4" balsa, and with some CF rod/plastic tube/velcro/a spring etc etc knocked up the following:-
It is extremely accurate, simple & cheap to build, nearly all of its weight sits over the LE (so does not deflect flaps/ailerons etc), and the upgrade app was the cost of a Mars bar.(although, for our purpose obviously unneccessary as we don't need 1% accuracy, but the upgrade allows us to zero on the tailplane, then the wing can easily be measured relative to this)
You may need to reduce the width of the "V's" significantly for wings which are not constant chord, otherwise, as the LE or TE are only in contact at one point, at some distance from the rod, there will be some up/down play at the other end of the V. (I am sure you can see what I mean...I had to reduce mine since pic was taken)
Give it a works!!
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