A build-log of 1:16 scale GippsAero GA8

Started by tantragna, August 13, 2014, 08:31:49 PM

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tantragna

Hello folks, if anyone remember my early posts in this forum about my ambitious re-entry to the hobby with a professional approach. Well, I went busy buying all the THINGS necessary to make it happen and infact started the process little more than a month back. Sorry for the delayed relay of the things happening.

For a brief on how the model/aircraft looks, here is a below video of it.
www.youtube.com/watch?v=RE9kyPnp0_g

I started with a plan, fetching from wikipedia. Yes, if you notice the fin, we will find the mahindra logo. That is because, Mahindra Aerospace has acquired a major stake on the Australian GippsAero a few years back. I liked that aircraft so much, even before the facts of the Mahindra's domination and with that info, decided to build it as it is relatively simple [oops, I was wrong :giggle:] to build.

The build has been on and off since a month, 2nd July to be for exact start date. I got serious after the first sketch of the plan was ready and started to collect the necessaries to make it happen. The reason why I chose this aircraft was it is very much boxy, with rounded corners/edges, so thought will make a SPAD. Ooops again, it went on to knock off the 'S' and install 'C'. It became a bit more complex, nowhere near to simple. In the process of getting the material, I found a newer material, a coro again but with much difference. It is many times heavier to its equivalent 'flute coro', this new coro is cellular/honeycomb and has thick skin on one surface. It is a lot tough to work than the flute coro, depron and even the balsa, because it is really that tough. A couple of meters of cutting through and the blade looses it sharpness. A real pain in the rear side :giggle:


The scale of the model I chose was 1:16, which is 768mm, ie., about 2.5 ft in wing span and about 2 ft in length. Expected AUW around 500gms, 5 channel control with flaps. That is because of the first purchase of motor/esc could probably only support that size. Here is the few clicks I had during the initial days.

more soon...

tantragna

Used the nt-cutter blades to get a uniform trailing and leading edges [with some rcd help  >:D ]. Before to that, the aviation lamp wiring was donated by an old blown x'mer.

For the main-plane or simply the 'wing', I used a split 10mm carbon tube upto 80% of the entire span. The half tube was perfect to glue in and more than adequate for the strength. The bottom surface of the wing was the strong coro and two horns with a nylon toothpick each to hold in place with the epoxy.


tantragna

While the main spar was epoxied, went on to shop more build aid to make things easy..

Wanted the aerofoil supposed to be as stock as possible to look nearest to the real thing. Actually do not care if this thing flies or not.. just need a scale plane from external as much as possible! But still want to fly, lets see..

Even the good old guitar was kind enough to donate a couple [of what was left on it  :giggle:] of strings for the project.

yash10896

subscribed
good luck sir :)
seems like after i started building c17 members are getting interested in airliners :P
Regars
yash :hatsoff:
Challenges are what make life interesting and overcoming them is what makes life meaningful

tantragna

Ribs for better foil, and testing of the pins before gluing.. sorry for the mess on the table. The dining table is multitasking here than I had ever  :giggle:

The aileron control horn, rod/tube had to be customised due to its tiny scale. Good old ball point pen refills helped here.. Actually I need more now :giggle: Guitar string #3 plays its tune in tuning the aileron according to the 9gms rcb avionic servo and old debit card donated itself to become the horn [and more later].. And the x'mer's winding again for the aviation lamps through the wing base coro.. Formers and even longerons were cut for the fuse in the mean time..

Working with the cellular coro as mentioned earlier was a real pain, especially on the hard side [fake wood finish]. :'(

haha Yash  ;D!!

tantragna

Actually I have become toooooo lazy to even post nowadays.. too bad for myself grrr...

Back to the story,

Started to make a template with a odd-piece of the coro. added more measurements, with the uber-main components and more markings! As I told just above, my fat hind made its way to declare it as the final fuse.. so be it!

I was just amazed how tough the coro was and its loading capabilities. impressive. But strongly suspect it to be come a fat [say heavy] lady, and remain on ground for ever  :banghead: Again, lets see!

Original plan was to make use of the formers and longerons and use the flute coro for the skin, thereby being light. But I always go for strength and rarely for light weight, and if I recall correctly the last challenge in late 90's was the same issue and the airplane went on to become 12+kilos for a tiny 'super tigre 60'... dammit, not again! :o

Now the project really starts to crawl. [all these happened about a month back, so roll back 30days for it]

tantragna

It gains its heels.. the old paint tin's handle is the rear landing gear strut and the old discarded ball point pens for the front one [experimenting out here]

And more grooving and gluing, to fit as many strengthening as possible [+ more weight  :banghead:]. Really cant help myself here..


tantragna

#7
Patching this odd fuse piece [supposed to be a template] was getting to be a real pain now.. tail went on to show up like a real one, and engine cowling was fabricated.

Controls installed for a preliminary taxi test and it was a pleasure to see it roll with acceptable accuracy with the home-made steer wheel assembly. And it finally broke, when I pushed when the front wheel had locked and redid with relative ease the same day.

And the progress is more or less like this since a couple of weeks.. Will complete soon, also the weather has picked-up and have to wait for a better day to [try to] maiden it. Hope it flies [though the chances are 50/50].. if not, it will be hanged from the ceiling for eternity, post to stripping all the electronics  :giggle:

Edit: adding taxi test video

www.youtube.com/watch?v=lrGMilpX390

docnayeem

Great build....

tantragna


sanjayrai55


K K Iyer

Went through all the pics three times to appreciate the effort put in.
Lovely curvature on fuselage edges. And great edging of control surface external edges.
Very nice.
(BTW what about the top surface of the wing?)

tantragna

Thank you Sanjay sir.. Iyer sir, will be using 3mm flute coro to cover the top surface as per the original plan and all the remaining of the fillings too. then would be painting the white with enamel paint, then using signboard stickers or black enamel. Red stripe will be signboard sticker and so does the reg# and mahindra logo.

tantragna

Top openings of the fuse done, windshield/windows pending for acrylic/perspex work.. or maybe even just plain cellophane tape :giggle:

Wing controls [ailerons+flaps] installed, with an extra rib on port side. The nose wheel seized and had to be re-done, so removed here..

tantragna

Wing was being capped as replying to you Iyer sir ;) Here is the details..

tantragna

more wing capping details..

docnayeem

It's gonna be a masterpiece... Excellent workmanship....
By the way...  What is the cowl made of?  And as you said this coro is heavier.. Any estimate of the AUW?

tantragna

According to the scale max auw was supposed to be 440gms, but this one might hit ~600gms.. cowl is also coro. not a piece of wood used so far..

Hmm, masterpiece i doubt; challenging, u bet! I had faaaar better ones done in the past. will do a 1:8th scale soon, that should be close. its a challenge with micro scale to detail with functionality. Lets see, it all depends on how much I can afford..

K K Iyer

With all due respect, may i make a suggestion?

Before starting the next scale model, decide whether intended as a flying model, or only static/ ground runner.

Hope to see a project like this from you soon (pl see pic)

tantragna

May be sometime sir! need to feel the air for a while, before settling back inside 4 walls.. had seen in your earlier posts in another thread, very detailed and scale. need a dedicated space for such thing, definitely not the dining table stuff :giggle:

K K Iyer

Hey, hey, not my build.
This is world famous stuff on the net!

sanjayrai55

Tantaranga keep that weight under control!

At 2.5 feet that model should be less than 600 grams AUW :D

tantragna

yup sir, dying hard to keep it under control :giggle:

Below is my[oops.. our] earlier attempt on a scale build,

with early morning visitor

committment pic 2

poser :P

part in skeleton

fully skeletal

this thing went on to become 12+kilos  :banghead:

this is the only pic of completion with its owner

this was the color scheme/livery chosen for the model..

K K Iyer

Next time, to go below 12kg, dont cover with gold!

Forget/remember the failures.
Then carry on.
This so called 12kg model actually looks good, and probably weighs only 2kg!
Well done sir.

tantragna

hehe, what not went into it.. it was a chaos in finalising the building materials, went right from balsa, teak, ply and even duralumin.. and please dont address me 'sir', Iyer sire.. main bahut chota hun aap se..