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A Great (Blink) Success, if a little fat.

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A Great (Blink) Success, if a little fat.

Old 11-25-2013, 05:18 PM
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Aussie Damo
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Default A Great (Blink) Success, if a little fat.

Well my blink is back up and flying and what a hoot it is.

Its E powered with an outrunner brushless and a 2S 1300mAh battery all spinning a apc 6x4. Its rather fat in its current state after a few repairs at 9.6 oz but still has some go but not outright vertical. repairs are new tougher vertical stabilizer, reinforce leading edge on one side, some extra covering and some ballast in the tail to balance it out (all from putting it in a tree the other week after loosing sight of it trying to trim it out)

Apart from my habit of putting it in trees at the end of the flight while trying to land the only problem (if it even is one) is that I need a fair bit of up trim to get level flight, and as a result im loosing a fair bit elevator authority especially at slower speeds (hence the trees).

Here is what it is trimmed to for level flight at about 2/3 throttle (which it is motoring along at)



What do you guys think??? its balance is about 3/16 forward of where the plan shows and ive read on here with people having the CoG about 3/4 forward of what the plan shows (which would be about 17% of the MAC which i dont thing would be right)

Second question, what is it when the tail sort of corkscrews following the nose (ie the tail if traced from behind would be drawing .5-1 inch circles), it only happens at low speed in shallow angle of bank turns?

Any tips would be appreciated

When this one eventually dies I will definitely build another with a slight wider center box and no panel between the box and servo tray so I can lay my battery flat and slide it back as necessary to balance

Damo
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Old 11-25-2013, 10:48 PM
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combatpigg
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At 9.6 ozs the CG will be more critical than if the plane weighed 7 ozs, so work the CG back in 1/4" increments even if it means moving the motor back.
The fishtail at low speeds is from marginal fin area. The small fin gains effectiveness at higher speeds. The highly tapered wing doesn't help either. Wing tips with less than 4 inches of chord aren't doing much at this sort of wing loading.
Increasing the fin area [add a section in the middle of the existing fin] would shift the CG in your favor without a noticeable difference in weight if you choose good wood.

Last edited by combatpigg; 11-25-2013 at 10:56 PM.
Old 11-26-2013, 12:51 AM
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Aussie Damo
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Thanks Combat pig,
The fin size thing makes complete sense, is there a technical name for this??

CG wise I cant really move the motor back, its a x mount brushless so its attached directly to the firewall and that is epoxied in there well and good, also if i move it any more the prop will come close to hitting the leading edge.
I dont quite understand what you mean by adding a section in the middle of the fin.

Dont get me wrong, it flies pretty good, just a bit of a dog trying to land/slow speed, I guess that's to be expected from a heavy delta
Old 12-03-2013, 07:10 AM
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MJD
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On mine I ditched the pointy fin tip - pointy tips are nothing but drag generators - by clipping it to about 1-1/4" tip chord.

At almost 10 oz I think your days of flying slowly may be over..?
Old 12-03-2013, 10:34 AM
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Originally Posted by Aussie Damo
Second question, what is it when the tail sort of corkscrews following the nose (ie the tail if traced from behind would be drawing .5-1 inch circles), it only happens at low speed in shallow angle of bank turns?
Where does the front of your rudder terminate? It should be even with the forward spar, but from your pics, I can't tell.

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