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Apr 27, 2014, 11:37 PM
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Matty12's Avatar
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I don't know bud, I'm still trying to figure that out too.

TBH im a bit upset at my self that I didn't buy a radian.

I rebuilt my dragonfly wings with a CF spar, they should be ready to cover in a few days. It would be nice if the spar could be pulled out and replaced as a build mod but the wings really need to be broken apart. Fortunately my wings were broken apart for me
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Apr 28, 2014, 10:42 AM
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Flew my Dragonfly again this week. Unfortunately is was flat with no lift so still do not know how it will thermal. After all the wing problems I will tend to fly this carefully and not stress the wings . It looks nice in the air and handles well, treat it as a glider and not warmliner and it may last.
Apr 29, 2014, 12:15 AM
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Matty12's Avatar
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Andy, you could use three sections of CF, one for the centre and then push epoxy and the remaining cf rods out through the existing spar to extend it. Drawback is you would need a really long drillbit as some of the formers are ply.
The existing spar is really inadequate, it would be so easy to install an extra spar if the wing was foam!
Apr 29, 2014, 03:04 AM
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Andy1248's Avatar
Thanks Matty, I will have close look at my wings to see what I can do.
Apr 29, 2014, 03:54 AM
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That probably made no sense but I could draw that if you like, it may help that I'm acquainted with the insides of the wing
May 04, 2014, 09:33 AM
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Covered my wings today, quite happy with the result. The finish of the epoxy on the body is still a bit lumpy but it's structurally ok.

I did connect up my ailerons, they are still red so look quite nice with the white wings (white is what I had laying around). Just need to reinstall the ele+rud servos and she will be ready for maiden!

I'm getting excited, hopefully this glider will finally do what I bought it to do or it will go in the trash!!
May 09, 2014, 05:53 AM
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I had a few really nice flights with the Dragonfly this afternoon, surprisingly after it's extensive repairs it flies quite nicely! I added some down thrust when I re-set the motor mount which results in a much more even acceleration, just a few clicks of trim and she was away!
Still using the silly 6x4 prop but that provides enough thrust for me. Re-maidened with 1600 3s, stock motor and 65g ballast in the nose. CG 65mm.

Before:


After:
May 09, 2014, 10:15 AM
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That is good news.... Mine is still sitting in the box, I will get to it as soon as I finish some rearrangement of the house first
May 10, 2014, 07:11 AM
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Matty12's Avatar
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I officially now love this plane!!

Dragonfly at the beach (3 min 21 sec)
May 19, 2014, 08:36 PM
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I am glad of your opinion now had to go to a different version of youtube to view the video though....
May 20, 2014, 08:18 AM
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Can anyone advise me on the shaft diam and spinner size required for this plane and stock motor? 3-4mm??
May 26, 2014, 05:35 PM
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Hi Matty!
Following numerous hints on the hobby king site I don't use the stock motor but a ntm 1200kv 28/36. The shaft is 4 mm and fit the original mounting for folding propeller.
David
May 26, 2014, 08:42 PM
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Matty12's Avatar
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Oh yeah, thanks for that. I did measure it but forgot to post my findings. It's a 4mm shaft and 40mm spinner.
Jun 05, 2014, 11:26 AM
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HK Dragonfly quality issues


I purchased the HK Dragonfly and I would absolutely not recommend this airplane to anyone (buyer-be-were). I make this statement for the following reasons!
Quality issues throughout the HK Dragonfly:
Worst of all is the wing. I was concerned about the wing quality from day one. I have extensive experience flying sailplanes and I flew this HK model 7 times before the wing failed!! The right wing failed at the point where the carbon spar ends (built up balsa wing with no additional reinforcing for the remainder of the wing). I was aprox. 1,200 ft. up making a gentle right turn, the main wing failed, the airplane went into a fast spiral (roman candle) and hit the parking lot, the LiPo’s (3S) went into spontaneous combustion, destroyed the motor (replacement motor for the improperly supplied HK motor), destroyed the ESC, never found the right wing half with aileron servo, destroyed my Futaba 2.4 GHz RX, and of course the Dragonfly was a complete loss!
The HK supplied Motor is not matched to the folding prop. supplied with the ARF (will result in motor burning up if the prop. / motor is not changed out – 3S bat. As recommended by HK).
Wing saddle was not properly molded, had to build up one side of the saddle so the wing and horiz. Stab. were level to each other.
Poor design for airflow, had to increase the airflow inlet/outlet so the bat and esc received cooling air.
Jun 05, 2014, 09:43 PM
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Matty12's Avatar
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Sorry to hear about your crash, if you look back through this thread you will see the same issues again and again.

Though with modification I'm finding mine flies nicely but these are not trivial mods.


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