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Aviomodelli Caproni Calif A-14 . . after the crash.

Jolly Roger
Posts: 573
Joined: 30 May 2015, 20:35
Location: Sutton Bank, North Yorkshire

Re: Aviomodelli Caproni Calif A-14 . . after the crash.

Post by Jolly Roger »

Hi Max,

I've loved following your rebuild - good effort!

Just to make sure we are confused, :D I'm pretty sure your wing area is significantly more than 0.57m2.

Even if Aviomodelli stuck with the high aspect ratio of the original (25), you would have 0.68m2. But it's much more likely they widened the wing chord a little, so you probably have nearer 0.75m2. The 4m Alpina has over 0.80, by comparison.

The effect of this will be to reduce your wing loading significantly.

Assuming your 4.5kg mass is correct, I'd expect your wing loading to be about 60g/dm2. This is 19.7oz/ft2, in old money.

Oooh, I do love a spot of arithmetic. ;)

Good luck with the test fly.

Rog
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Max Wright
Posts: 198
Joined: 10 Mar 2020, 19:57
Location: Clayton Bay South Australia

Re: Aviomodelli Caproni Calif A-14 . . after the crash.

Post by Max Wright »

Hi Rog

Thanks for that. The maiden will be delayed as I've discovered that the aileron in the right wing has developed a twist over time, which has resulted in wash IN . . .

Caproni Calif A14-47.JPG

So I have cut it free and I'm going to re-set it using ammonia/water. Shouldn't take long.

But today I'm hoping to meet the Scouts blokes at Blanchetown so I can photograph the prototype of the Motor Falke.

The calculation of the wing area were done by taking the span and then drawing two triangles, and subtracting one. The span is 2.00 metres. The root chord is 195mm and the tip chord is 90mm. Hopefully your arithmetic will give us a better result. 8-)

Cheers
Jolly Roger
Posts: 573
Joined: 30 May 2015, 20:35
Location: Sutton Bank, North Yorkshire

Re: Aviomodelli Caproni Calif A-14 . . after the crash.

Post by Jolly Roger »

Oh dear - wash-in is not a good thing. Hope it comes out ok.

Thanks for the chord numbers Max. Based on the wing platform, that gives an area of 0.7186m2. If the mass is 4.5kg that’s a wing loading of 62.6g/dm2, or 20.5 oz/ft2. Anyway, I’m sure it will fly well. :D
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Max Wright
Posts: 198
Joined: 10 Mar 2020, 19:57
Location: Clayton Bay South Australia

Re: Aviomodelli Caproni Calif A-14 . . after the crash.

Post by Max Wright »

Thanks, Rog.

62.6g/dm² is better than 78.9g/dm² :D
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Max Wright
Posts: 198
Joined: 10 Mar 2020, 19:57
Location: Clayton Bay South Australia

Re: Aviomodelli Caproni Calif A-14 . . after the crash.

Post by Max Wright »

OK Sorry about the delay. I've stopped work on the Falke build to concentrate on getting this model ready for Bordertown aero-tow on 27- 29th of this month. We are ready for a hand launch tomorrow. Fingers crossed.

I've filled the nose with lead shot and covered it with PVA to keep it in place, and glued the original lead plug in with silicone.

Caproni Calif A14-48.JPG

Then I assembled my VicRC large model CG machine.

Caproni Calif A14-49.JPG

Because of the swept back wings, I balanced it with the CG at 25% of the root chord.

I can always add some stick on wheel weights if I need to.

Caproni Calif A14-50.JPG

Here are some random shots of it sitting on the balancer . . .

Caproni Calif A14-51.JPG
Caproni Calif A14-52.JPG
Caproni Calif A14-53.JPG

When the retro fitted retract goes up and down there is a slight deflection on the balance pointer.

Hardly noticeable.

Don't know why I have an extra copy of the photo. :?
Attachments
Caproni Calif A14-54.JPG
Max
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Max Wright
Posts: 198
Joined: 10 Mar 2020, 19:57
Location: Clayton Bay South Australia

Re: Aviomodelli Caproni Calif A-14 . . after the crash.

Post by Max Wright »

Before we could start hand launching, my friend who was helping me, suggested we try lifting the model at the wingtips to confirm where the CG should be.

As the fuselage lifted clear of the table, a dimple about 50 mm across appeared in the middle of the upper sheeting of the wing; about 1/3rd the way out from the root.

It is clear that some internal damage has occurred to the spar at that location. A similar, smaller dimple also appeared in the other wing at about the same spot.

We decided that it would be necessary to insert a strip of 1 mm carbon fibre on its edge, into the wing.

Unfortunately I won't be able to do it before Bordertown, so the A-14 will become a hangar queen for the time being.

I will turn my attention in what free time I have, to starting the Motor Falke build.
Max
john greenfield
Posts: 497
Joined: 18 Mar 2015, 07:52
Contact:

Re: Aviomodelli Caproni Calif A-14 . . after the crash.

Post by john greenfield »

Max

Unless you intend to do violent aerobatics it is a bit extream to try lifting a model like your Calif by the wingtips. A much more realistic test of the strength of the wings would be achieved by lifting at around 1/2 span.
I do accept however that if you have a localised deformation in the wing skin, it needs investigation.

AEB
AEB = Aeronautical Energiser Bunny (with thanks to CW)
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Max Wright
Posts: 198
Joined: 10 Mar 2020, 19:57
Location: Clayton Bay South Australia

Re: Aviomodelli Caproni Calif A-14 . . after the crash.

Post by Max Wright »

Yes. We did it very carefully, John.

But it doesn't look good. :roll:

Cheers
Max
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