Auster A.O.P.9 build thread!

[danielburgess]

It seems I have 2 weeks off, so decided that I should finally try my hands at actually building something. I narrowed my choice to 3 planes;

1) Auster A.O.P.9 "British"
2) Fieseler Fi 156C-2 "German"
3) Kokusai Ki-76 "Japanese"

Reasons why I chose this, hmmm, I wanted abit of both worlds, a high-wing trainer, and war bird at the same time, and I just love the "STOL" characteristics all three possess!

Made a trip down today to Art Friends to stock up, be warned! There is no blue foam at Takashimaya branch, only Bras Basah has them, so I will be starting on the wing later.

Engine of choice is a .25 Thunder Tiger, contributed by a fellow forummer, and managed to get it back up and running!

Cheers!

[Tony]

Great choice of subject to model. The Auster is a pretty unique plane and a refreshing change from the all too many P-51's, P-47's etc etc etc. Looking forward to following your build thread.

[danielburgess]

Auster A.O.P.9

Thanks Tony, ya, to me the Auster A.O.P.9 is a combination of the Piper Cub, Bird dog, etc. Plus, I am a sucker for planes from the "Eagle Of The Crown".

I'll be starting on the horizontal and vertical stabilisers today, lazy me, they are the easiest pieces to build, and will be made from 3/16 inch balsa wood planks. Will post up the pictures by late afternoon or evening!

Cheers

[Tony]

Are you building from plans or your own design? I recall vaguely that Flying Scale Models (or could it be AMI) had a free plan for the Auster meant for a 25 engine quite sometime back. Are you using that plan?

[danielburgess]

scale.

Anyone knows what is a good scaled down ratio for this plane if I were to be using the .25 engine? I was thinking 1/6 scale, but is that too big?

Cheers

[Tony]

If the Auster is approx the size of a Cub then 1/6th will probably get you something like around about 65-70 in wingspan. Way too big for a 25. Try 1/10.

[danielburgess]

auster

Nope, no plans at all, I will go check up AMI for it though, 1/10 sounds good, so the wingspan will be about 1.11m if it is a direct scaled down!

Cheers

[Tony]

If you went with 1/9th scale, you'd get 1.23m. Perhaps a better choice for a more scale like flight (lower wing loading)? What is the wing area going to be like with 1/9th?

[danielburgess]

Auster.

Hmmm, with a 1/10th scale, I get a wing area of roughly 0.19 square metres, and with the 1/9th scale, I get 0.24 square metres.

Cheers!

[danielburgess]

Auster

I just finished with the vertical stabiliser, uploaded some pictures of them, sorry for the poor quality, it is a handphone camera. Will continue next with the horizontal stabiliser. I need some advise on hinges for the control surface, what do you guys normally use?

Cheers

[Tony]

I am a little it out of touch here with this size of plane but if you compare with say Pilot's Seduction 123 - a 25 class aerobatic plane, its got 465 sq in (3.229 sq ft) of wing area. All up weight (AUW) should be around 3.5 pounds or 56 oz. This gives a wing loading of 17.3 oz per sq ft. Quit decent for an aerobatic plane in this class.

If you go with 1/9 scale you get 0.24 sq m or 372 sq in = 2.583 sq ft. With an AUW of 56 oz you get 21 oz per sq ft. With that kind of wing loading, she is not going to be a floater. You'll need to get it down to about 14-15 oz per sq ft or less to get her to fly more scale like.

My two cents worth.

[danielburgess]

Auster.

Hmmm, ya, my plan now is to compensate by using a slightly longer wing, to increase the wing area. Is it cheating!? Ha ha, anyway, I just finished the horizontal stabiliser. Pardon my horrible building skills!

Cheers

[danielburgess]

Auster.

Hi,

Starting to plan out the fuselage now. Having a little problem, what is a good engine mount? I was thinking of 2 wood beams coming out from the fuselage parallel to each other. See the picture for details.

Cheers.

[Tony]

Hi,

Starting to plan out the fuselage now. Having a little problem, what is a good engine mount? I was thinking of 2 wood beams coming out from the fuselage parallel to each other. See the picture for details.

Cheers.

Or get a fibreglass radial engine mount from LHS.

[danielburgess]

Do they have it at Rotor? I am heading over there later to get some stuff.