RC India

RC Models => Kites, Trains, Free Flight and All Others => Topic started by: K K Iyer on January 27, 2025, 09:09:08 PM

Title: Auster AOP 9
Post by: K K Iyer on January 27, 2025, 09:09:08 PM
Hi everyone,

Next fortnight I'm going to Ahmedabad, where my childhood buddy's group flies every Sunday.
Thought of taking something different - an electric control liner and a rubber powered free flight.

This is the rubber FF.

Downloaded oz759 from outerzone
Took it on a pendrive to the printer and got a printout (A2)

Now the first problem.
It's built entirely out of 1/16" sheet.
Just 2 sheets of 1/16x3x12

But the sheets I have are 1mm and 2mm (nominally)
Actually 1/10" and 1/20"

1/20" felt too flimsy, so decided to go with 1/10"
Should have sanded it thinner, as it was very difficult to cut these small parts out (it's 12lb/cft!)

Cut the parts outline portion of the plan and glued it to the balsa.
Realised later that instead of cutting out not quite identical ribs individually, it'd have been far easier to sandwich rectangular blanks and sand them to shape.
Now it's impossible to cut the slots in the ribs for the flat LE&TE.
So prune the ribs and butt to the LE&TE.
Title: Re: Auster AOP 9
Post by: K K Iyer on January 28, 2025, 09:07:06 PM
A little progress today.
Shaping the LE, tapering the TE, and making all the ribs identical wasn't too easy due to the small size...
Title: Re: Auster AOP 9
Post by: Arvindkharebpl on January 29, 2025, 11:03:49 AM
Thanks Iyer Saheb for sharing beauty of real Aeromodeling . Nowadays I think no body making these rubber power model . keep it up ,I will also try to get in rubber power model also
regards arvind Khare
Title: Re: Auster AOP 9
Post by: K K Iyer on January 29, 2025, 04:08:43 PM
Quote from: Arvindkharebpl on January 29, 2025, 11:03:49 AMThanks Iyer Saheb for sharing beauty of real Aeromodeling . Nowadays I think no body making these rubber power model . keep it up ,I will also try to get in rubber power model also
regards arvind Khare

The best thing about these small models is the minimal cost. A single 3x36 sheet is enough. And you can get prop hubs and rubber from Mr Madhav Khare in Pune.
Title: Re: Auster AOP 9
Post by: sharlock on January 30, 2025, 08:14:47 PM
so you will cut all the parts using a cutter or do you have a scroll saw?
Title: Re: Auster AOP 9
Post by: K K Iyer on January 30, 2025, 08:43:04 PM
Basically you only need a steel ruler, a #11 surgical blade with handle, and a sanding block.
It helps if you have a razor saw and balsa stripper...
Title: Re: Auster AOP 9
Post by: K K Iyer on February 03, 2025, 08:07:20 AM
Bare bones. 17gms.
Title: Re: Auster AOP 9
Post by: K K Iyer on February 03, 2025, 07:17:01 PM
Cabin glazing, undercarriage, some stripes, and regn number pending.
Title: Re: Auster AOP 9
Post by: sanjayrai55 on February 04, 2025, 10:50:22 AM
Charming!
Title: Re: Auster AOP 9
Post by: WeekendFlyer on February 04, 2025, 11:52:21 AM
Very Charming  :hatsoff:
Precision work

Which material is being used for covering the model?
Title: Re: Auster AOP 9
Post by: K K Iyer on February 04, 2025, 11:31:19 PM
@Sanjayrai55

Thanks. Actually I was wondering ki aapka koi bhi comment kyon nahin aaya!
Title: Re: Auster AOP 9
Post by: K K Iyer on February 04, 2025, 11:33:48 PM
@WeekendFlyer

Thanks Dinesh.
Btw, I lost your phone number when my phone died recently.
Perhaps you could Whatsapp it to me.
Regards
Title: Re: Auster AOP 9
Post by: Free Flight on February 05, 2025, 07:02:52 AM
Wonderful creation. In my opinion, you achieved a respectable AUW weight. I don't see a DT attached yet. Highly recommend it for your latest creation.

PS : Looks like you have fixed the stab. Any built in incidence or you have a gap to adjust incidence with scraps?
Title: Re: Auster AOP 9
Post by: K K Iyer on February 05, 2025, 11:29:01 AM
Quote from: Free Flight on February 05, 2025, 07:02:52 AMWonderful creation. In my opinion, you achieved a respectable AUW weight. I don't see a DT attached yet. Highly recommend it for your latest creation.

PS : Looks like you have fixed the stab. Any built in incidence or you have a gap to adjust incidence with scraps?

Thanks Manav.
No need for DT as it isn't going to climb like your catapult gliders!
Too heavy for its 22" span 66sqin wing, 3.4oz/sqft.
Didn't have 1/16 sheet, only 1 & 2mm (actually 1/20 and 1/10")
I used the 1/10" to cut strips from.
Realised later that 1/10sq is 2.5 times 1/16sq.
And my balsa is 9oz/cft, not 6!

Fixed stab, but wing is on 2mm runners that can be sanded for incidence adjustment. Neat idea, no?
Title: Re: Auster AOP 9
Post by: Free Flight on February 05, 2025, 01:23:49 PM
That is very good weight using a bit heavy lumber. Yet 30 grams/ 66 square inches puts you at a descent 0.45
grams per square inch, quite good. Once blessed by the thermals gods, your model can easily be OOS. From my experience, most E20 models are about 30 grams at 70 square inch wing, and have gone OOS. 

Yes, neat way to adjust the wing incidence.

Wishing you the best for your trim and flight sessions. Let us know how it it all turned out as the model is beautifully crafted.
Title: Re: Auster AOP 9
Post by: K K Iyer on February 05, 2025, 03:10:30 PM
30 gms several steps before completion.

44 gms !
With cabin glazing, undercarriage, 5gm rubber and 5gms lead in the nose.

So the problem is not OOS, but whether it'll fly at all  :banghead:
Title: Re: Auster AOP 9
Post by: Free Flight on February 06, 2025, 06:38:12 AM
I see now. Misunderstood the photo above.

But you should be able to enjoy it. The difference between a high and low wing loading, assuming both are were trimmed well is the sink rate. Heavier models do not climb as high as the lighter model. Do let us know as to how it did.