RC India

This is adapted in Corro from the Great Planes Piper Cherokee Archer, plans available on outerzone.co.in

(http://s25.postimg.org/cjw4vrz9b/IMG_20150727_052031.jpg)

(http://s25.postimg.org/8dbagfznj/IMG_20150727_052046.jpg)

(http://s25.postimg.org/ego9mm0jj/IMG_20150727_052104.jpg)

Started with the fuse and tail feathers

(http://s25.postimg.org/ys048wsvz/IMG_20150727_052120.jpg)

(http://s25.postimg.org/wuysqlcu7/IMG_20150727_052125.jpg)

(http://s25.postimg.org/7eqc0ewxr/IMG_20150727_132545.jpg)

(http://s25.postimg.org/9brniqczj/IMG_20150728_102039_HDR.jpg)

(http://s25.postimg.org/3z2t4lp33/IMG_20150728_114034_HDR.jpg)

(http://s25.postimg.org/q9v9ibbr3/IMG_20150728_200208_HDR.jpg)

(http://s25.postimg.org/cewyzuhbz/IMG_20150728_200244_HDR.jpg)

(http://s25.postimg.org/daov1k1mn/IMG_20150727_072350.jpg)

(http://s25.postimg.org/590mjniv3/IMG_20150727_083024.jpg)

(http://s25.postimg.org/gk3a80pq7/IMG_20150727_110836.jpg)

(http://s25.postimg.org/w84het5bz/IMG_20150727_110813.jpg)

Planning to use a CF main landing gear, which will require a fair amount of fitting of a LG baseplate

Also, a seriously involved topsides consisting of a Cockpit and turtle deck

Sanjay ji a beautiful choice. Just dusted out my old cherokee - a biofom model which has a cox engine.

A lovely looking model, {:)} have seen the yellow version of this in my field.

Ashok-ji - looking at that is giving me a serious inferiority complex  :o

Lovely one. Is that balsa skin covering the foam wings?

Jana - I have a long long way to go still.

Also putting flaps

Sanjayji I am sure you will do a better job.

The wing is balsa frame (leading and trailing edges and balsa ribs) with biofoam sheeting. Actually, the biofoam was given one coat of araldite and left at that. So after years of gathering dust, took it out and will complete it before this flying season. Sanded part of the fuselage today. Will modify it to electric. I will stop here and not hijack your thread.

Fuselage paint needs time to dry in this weather, so on to the wing

(http://s25.postimg.org/6okkrcdhb/IMG_20150728_190341_HDR.jpg)

(http://s25.postimg.org/cs6qozt4v/IMG_20150729_063609_HDR.jpg)

Landing Gear Block

(http://s25.postimg.org/jq69h71vj/IMG_20150729_073618_HDR.jpg)

(http://s25.postimg.org/ctgoieuyn/IMG_20150729_074257_HDR.jpg)

(http://s25.postimg.org/ggwfoh35r/IMG_20150729_125742_HDR.jpg)

(http://s25.postimg.org/67zd4wpq7/IMG_20150729_195728_HDR.jpg)

(http://s25.postimg.org/smh1l4shr/IMG_20150729_195714_HDR.jpg)

(http://s25.postimg.org/dljchlz5r/IMG_20150729_201430_HDR.jpg)

(http://s25.postimg.org/5ercq1933/IMG_20150729_201440_HDR.jpg)

(http://s25.postimg.org/vvvgrlglb/IMG_20150729_202325_HDR.jpg)

Sir,
UC is CF or painted dural?
I find at least one new intriguing item in every new model from your hangar!
Regards

Iyer sir, it is CF.

I wanted to buy an Alloy LG from HK, but it was out of stock. This was about $ 2 or so more, so I took it.

Hope it does the job  :)

Great work Sanjay sir

Thank you Sujith. Long time; trust you are well

Coming up very well Sanjay sir...

Excellent work sanjay sir {:)} {:)} :salute: :salute:

Its a corobalastic built sir.

Thanks Girish

Thanks Gaurang

:thanks:

Quote from: rastsaurabh on August 01, 2015, 12:46:53 PM
Its a corobalastic built sir.

Corroballistic Saurabh?  :giggle: :giggle:

I guess I say  :thanks:

I was emphasizing on coro and balsa
But u defined better ballistic build with coro and balsa.

Cockpit/Cabin started

(http://s25.postimg.org/8vtvcdp33/IMG_20150730_184051_HDR.jpg)

(http://s25.postimg.org/hkcf62fcv/IMG_20150730_184447_HDR.jpg)

(http://s25.postimg.org/5widbiq7z/IMG_20150730_184442_HDR.jpg)

Aah, corobalsiaticious?  :rofl:

As a corro bend is rounded, on the fuse top, to get a better fit I kept a little overlap.

(http://s25.postimg.org/6sjg4ppa7/IMG_20150730_195551_HDR.jpg)

(http://s25.postimg.org/dmp5gnsjj/IMG_20150730_185310_HDR.jpg)

(http://s25.postimg.org/xrnazvbr3/IMG_20150731_113137_HDR.jpg)

(http://s25.postimg.org/ik2q1ruin/IMG_20150731_204410_HDR.jpg)

Looks like the cabin topsides of a boat - a Cabin Cruiser  ;) ;D

Sanding Sealer

(http://s25.postimg.org/v6d4ylwzj/IMG_20150801_104144_HDR.jpg)

(http://s25.postimg.org/88qd942tb/IMG_20150801_104155_HDR.jpg)

Nice idea on using the balsa for the cabin sir. gives the perfect shape. :salute:

Not much choice actually. Balsa, or HD Foam

Wonder how I missed this build.....

Sanj you have a production line going...

Another super build going on here...what next??

 :rofl:  VC once called it Gurgaon Corro Factory  :giggle:

Yes VC you hit the nail on the head. Corro Factory is indeed the one at Rai residence.  
Glad it's at Sanjays than anyone else's .

Sanj, at least you share all your expertise and knowledge with all of us at RCI.

We are all always learning. I for one at 56 years of age have learnt how to build  Corro planes that can actually fly like balsa ones.

Inspiration and knowledge gained  by your prolific building.

Progress

Wing completed

(http://s25.postimg.org/r93nefebj/IMG_20150803_063358_HDR.jpg)

(http://s25.postimg.org/5b76kmzb3/IMG_20150803_121100_HDR.jpg)

(http://s25.postimg.org/vyy6grupr/IMG_20150803_121025_HDR.jpg)

(http://s25.postimg.org/ephpi64vz/IMG_20150803_121139_HDR.jpg)

Cabin/Cockpit complete

(http://s25.postimg.org/950mtsgn3/IMG_20150803_120903_HDR.jpg)

(http://s25.postimg.org/3ksqww75r/IMG_20150803_120917_HDR.jpg)

(http://s25.postimg.org/eqrnbl6pr/IMG_20150803_131737_HDR.jpg)

Awesome build :D {:)}

Looks real scale. Waiting for complete plane

Thank you Kiran and Satish Satz  :thanks:

(http://s25.postimg.org/r01xu4t33/IMG_20150804_065219_HDR.jpg)

(http://s25.postimg.org/pz1p50c3j/IMG_20150804_065228_HDR.jpg)

Not entirely happy with the corro turtle deck.

I thought the corro would be rigid enough although I had to flatten the flutes on one side for the bending. It wasn't  :(

Next time I will use balsa stringers on the formers

(http://s25.postimg.org/6jqxbwitb/IMG_20150804_065242_HDR.jpg)

Making an engine cowl. Fabricated from Balsa bits and pieces lying around: means lots of cyano and lots of sanding  ;)

(http://s25.postimg.org/6igzihgzj/IMG_20150805_065633_HDR.jpg)

(http://s25.postimg.org/fu31fftj3/IMG_20150805_065642_HDR.jpg)

(http://s25.postimg.org/ontxwjghr/IMG_20150805_121026_HDR.jpg)

great! sir

coming out very nice sir. :salute:

Thank you Abhay and Jana  :thanks:

Elevator Servo

(http://s25.postimg.org/htstyc2m7/IMG_20150806_140000_HDR.jpg)

(http://s25.postimg.org/6vhkg5e0v/IMG_20150806_140006_HDR.jpg)

(http://s25.postimg.org/j6aj0801r/IMG_20150806_140014_HDR.jpg)

(http://s25.postimg.org/ujx2bfakf/IMG_20150806_140038_HDR.jpg)

(http://s25.postimg.org/htstyc2m7/IMG_20150806_140000_HDR.jpg)

(http://s25.postimg.org/6vhkg5e0v/IMG_20150806_140006_HDR.jpg)

(http://s25.postimg.org/8ei0i8qwv/IMG_20150807_060512_HDR.jpg)

(http://s25.postimg.org/e04fmarlr/IMG_20150807_124206_HDR.jpg)

(http://s25.postimg.org/up5vi7o73/IMG_20150807_124242_HDR.jpg)

(http://s25.postimg.org/8jqd5nnlr/IMG_20150807_124306_HDR.jpg)

Sanjay sir, nice build. What is the source of white ply?

Thank you Mohan

It is from RC Bazaar. Price is OK but be careful on shipping. Earlier I had got from Krunal (Gajjark)

exellent job sir!!

Thank you Prabal

Complete, finally. Really took a long time

(http://s25.postimg.org/4eonb84lb/IMG_20150808_205156_HDR.jpg)

(http://s25.postimg.org/ar3sl27nj/IMG_20150808_205144_HDR.jpg)

(http://s25.postimg.org/xicv7gsov/IMG_20150808_205119_HDR.jpg)

(http://s25.postimg.org/691hsyrlr/IMG_20150808_205103_HDR.jpg)

(http://s25.postimg.org/pupyp5u0v/IMG_20150808_205008_HDR.jpg)

(http://s25.postimg.org/4eonb84lb/IMG_20150808_205156_HDR.jpg)

Biggish model. 62" span, 2.8 Kg. Using an OS 55 AX

Hope there is fair weather tomorrow

Surely it will be less than 30km we have here!
That Cherookee will fly just fine.
Best of luck.
Just think of all the people you have inspired into coro...

Unbelievable finish, best wishes for maiden flight👌

Sir........ji.       no words for this scratch build......its like a RTF.

Raining and raining since 6 am without let up. No chance for maiden. And unless Anwar relaxes till next weekend this model won't make the sweepstakes :(

Excellent work and best wishes Sanjay sir :hatsoff: :hatsoff:

Builds getting better by the day
Beautiful build as usual. Best wishes for a smooth maiden.

Sanjay sir... U have used 3mm corp for ic engines???

It's great as usual.

Quote from: K K Iyer on August 08, 2015, 10:09:45 PM
Surely it will be less than 30km we have here!
That Cherookee will fly just fine.
Best of luck.
Just think of all the people you have inspired into coro...

Thanks Boss. But.... the rain started at 6 am and continues!

Thank you Mohan and Saurabh  :thanks:

Quote from: Dr. Abhishek Agrawal on August 09, 2015, 08:33:37 AM
Excellent work and best wishes Sanjay sir :hatsoff: :hatsoff:

Thanks Doc

Quote from: ashok baijal on August 09, 2015, 09:16:49 AM
Builds getting better by the day
Beautiful build as usual. Best wishes for a smooth maiden.

Thanks Ashok-ji. But the rain......

Quote from: Devanesan Andrews on August 09, 2015, 09:26:33 AM
Sanjay sir... U have used 3mm corp for ic engines???

Dev the fuse is 4 mm Corro with 2 mm ply backing in front, wing is 3 mm, tail feathers and ailerons are 3 mm doubled

Thanks Satish  :thanks:

This looks like a balsa ARF model. Kudos sanjai sir for the finish .  :salute:

Arre waah waah waah, arre waah waah waah arre waah waah waah.
Awesome build.

Thank you Jana and Nitesh  :thanks:

 :salute: fantastic :bow: :bow:

Thanks Rohit

Looks fantabulous

Thank you Ghanesh

This model definitely needs to flaunt a Piss on Balsa sticker.  Fantabulous Model.

Thanks Colonel saheb :D

Let's hope the weather is good this Sunday. Maiden planned

Yes sir my papillon is also waiting.

Finally maidened it  ;D ;D

High winds. So I asked my good friend Group Captain Ramesh Tahlan (retired) to maiden it  ;)

I had taken my camera, but realised I had left the memory card in the laptop since the last time I used it. So - Girish's camera

https://youtu.be/8MYvzAPYFzk (https://youtu.be/8MYvzAPYFzk)

So we have some very good video of landing and take-off, and some very good audio in between  :rofl:

The model flies very well. Despite a strong cross wind, it was very steady and stable in the air. Although it cruises at 40% throttle in a very scale like flight, it is capable of most sport aerobatics

Would highly recommend it for someone who wants to make a 46 size Sport Model

Maiden last day! Wow  {:)}

Thanks Ashok-ji. Finally had some clear weather - very windy though

After the maiden..... ;D

(http://s25.postimg.org/6ark40mrj/IMG_20150906_WA0010.jpg)

(http://s25.postimg.org/wx40szqyn/IMG_20150906_WA0026.jpg)

Sir, it nice to see coro getting into Nitro... hope this will attract many more to try their hands on coro.

from far its hard to tell its balsa or coro.

regds
SR

Thanks Saurabh

Actually Spads started purely in Nitro. The original site was spadtothebone.net and still is. The mirror site with forums is spadworld.net. One of the reasons was Spads were perceived to be heavy, and Electrics in those days meant brushed, geared motors and NiCd or NiMh batteries!

The only popular electric spad I have known is Bex's Avispad. In fact when I started out in Electric Spads I, and many others built this - I built 3  ;D

Later on I started adapting balsa-nitro designs I found to electric, with some success. As I progressed, I discovered with proper build techniques, Corro could be built lighter than balsa!

I got a PM, which I choose to answer here, just in case any others have similar doubts

"hello sir,
this pm is regarding the piper cherokee of yours.
will a 3536 1100kv suffice?"

Anyone who has followed my Corro builds will realise I have done a large number of Balsa/Nitro conversions to Corro/Electric. Although I do not claim to be, nor am, any sort of authority, a few fundamentals based on schoolboy physics tell me:

A prime mover, whether an electric motor or engine has a few basic output characteristics _

Power - measured in Watts or HP normally
Torque - unit is eg N-m, dyn-cm, foot-pound etc
RPM - inv. sec
Power = Torque X RPM; ie the rate of doing work

For an electric motor: Power = V X A
For an IC Engine, Power = PLAN X K
P= Brake Mean Effective Pressure, a combination of Compression Ratio, Fuel Thermal & Combustion Characteristics etc.
L A = Length X Area or swept volume in cylinder
N = RPM
K is a constant depending on Units of measurement eg MKS, CGS, FPS systems

For a model to fly successfully, the prime mover (or Power Source) should be able to swing a propeller of desired diameter and pitch at a desired RPM. Which would need appropriate Power, and Torque.

In the case in question, the Cherokee as stated earlier has a weight of 2.8 Kg, or ~ 6.2 lbs. It is a low wing sports model, and would need 100-125 W/lb to fly, going by a rule of thumb. It would therefore need about 620 - 775 Watts power.

The motor in question (Avionic) has the following performance data as per RCB website

PROP – 10x7E
● Get 1600gms Thrust
Lipo – 3cell 11.1V
Operating Voltage – 10.8V
Amp draw at load – 32.7 amp
ESC - 30 amp
Power – 327W


PROP – 11x5.5E
● Get 1900gms Thrust
Lipo – 3cell 11.1V
Operating Voltage – 10.8V
Amp draw at load – 32 amp
ESC - 30 amp
Power – 300W


PROP – 9x4.7E
● Get 2000gms Thrust
Lipo – 4cell 14.8V
Operating Voltage – 13.8V
Amp draw at load – 42.5 amp
ESC - 40 amp
Power – 595W


PROP – 10x7E
● Get 2300gms Thrust
Lipo – 4cell 14.8V
Operating Voltage – 13.6V
Amp draw at load – 48.5 amp
ESC - 40 amp
Power – 630W


PROP – 11x5.5E
● Get 2700gms Thrust
Lipo – 4cell 14.8V
Operating Voltage – 13.6V
Amp draw at load – 47.2 amp
ESC - 40 amp
Power – 613.6W

So it is clearly not enough Powr.

Another point which I would advise caution on in selecting a motor - do not go by the maximum output of the motor. If you have to fly at full throttle continuously it is not a very smart selection at all! Better have a motor of at least 25% higher rating.

hello,
thank you for answering my queries.
but cant the model be built lighter? (i.e when you remove the engine, its accessories and extra supports for the engine)
the weight would significantly go down.
or another method,
scaling the plans down a little.
I obviously may be wrong in what i am suggesting above! ;D

In my experience, once you cross a certain threshold, eg a 25 size engine, the motor/engine equation shifts in favour of the engine. ie, the Battery/ESC/Motor combination will start to weigh more for a decent flight time (7 minutes or more)

There is not much weight reduction for fuse strengthening: you still have to design for the power and torque

On scaling the plans - I don't venture much into the Airframe design, so I cannot comment. Suffice to say that IMHO it really needs very advanced knowledge to be done properly. If someone wants to do a Mickey Mouse job, that is their affair

@sanjaysir .... aaap toh senti ho gaye yaaaar !!!!!!

Sorry sir if i have hurt your feeling or have said anything wrong.....
From the message of shavik sir above,
i feel that i have done something wrong.

I deeply apologize....

Not at all Prabal!

Don't worry about Shauvik - nowadays he comes on the forum once a year and creates some hungama then vanishes  :rofl:

@prabal  dude   hah ha ha  .. no need to apologise .... i was joking


@sanjaysir - u still owe me a plane ................   hungama apna style hai sirjeeee

Quote from: prabal276 on October 11, 2015, 07:09:16 PM
but cant the model be built lighter?

@prabal276,
Nothing wrong in your post, just that you could have thought a bit more about your query.
If it could be built lighter (without sacrificing strength and economy) Rai saheb would probably have built it lighter.
His specialisation is coro conversions of dozens of well known designs.
He has been able to bring down the airframe cost to Rs 500 or so, and now even the weight below that of an equivalent balsa/ply model.
So I think the answer is Yes, it can be built lighter, but for the same strength, it may be costlier!
(As Shauviks says, you made Rai saheb go senti..., and, as he says, no need to apologize. You too are doing some good work)
Regards.

Link to all pictures:

https://postimg.cc/gallery/1zs84yfbg/