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Old Dec 31, 2012, 11:49 PM
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Meringandan, QLD , Australia
Joined Jan 2011
2,960 Posts
Flaps Fitted and Tested, Serviceable

I have posted my Build and Maiden flight review on my blogg for the PC9.

I decided that the model did need flaps to help slow her down for landing on the rough surface of my park.

Before I did anything I gathered all required materials and had a very good look at the wings, and studied some photos of PC9's landing with flaps deployed.

That done, I decided on some down and dirty Zap Flaps which are not quite scale, but I had to leave some wing at the root so that structural strength of the wing was not compromised.

I marked up all of the areas where I'd have to take the scalple to the foam, measured carefully so that each side was a mirror image of the other.

The most time consuming part was finding 2 servos in my parts drawer which would function in the same direction. (thank goodness for the HK servo tester)

Once everything was marked up, I took a brand new hobby knife and made my cuts. The first was the servo recesses, then the servo lead channels, then the flaps were cut away from the wing. I then had to cut the hinges into place. These were carfully measured so that they were the same on each side.

I found some short servo rods which were ideal for the job, and then I measured and fitted the horns so that they had maximum strength and provided maximum throw.

All glueing was done with Zap 5 min epoxy.

Before glueing anything, the flaps were dry fitted and tested with the Y lead plugged into the servo tester.

Once all was correctly fitted and glued, I programmed the radio for 3 positions. Full Up, stage 1 and Full Down.
I used the servo slowing function on the DSX9 to slow the deployment of the flaps, so that any pitch attitude changes resulting from deployment were slowed. I did, however, make the retracting of the flaps as normal so that if anything were to go wrong when the flaps were deployed, then I could get rid of them quickly and sort out any other issues immediately.

The test flight.
I did a normal flapless take off, then climbed to height (60 + feet).
I brought the model around onto a long upwind, then deployed first stage of flaps.
No noticeable pitch attitude change.
I repeated the process for full flap with the same result.

On landing, I deplyed full flap on base turn, then brought her in.
On short final I chopped the throttle then used elevator to control the nose attitude as she sank in.
I was able to conduct a very well controlled landing as the flaps allowed the model to float through nicely as the speed bled off.


The next trick was to try using flap for take off.
I used first stage of flap for take off, which brought the model off the ground much sooner, permitting a very nice , scale looking, departure.

This has been the first time I have attempted to modify a model in this way.
Thanks to posts from others on various threads on how best to install flaps on a model, I have been able to considerably enhance my flying enjoyment of this model.
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