Hi All,
   I am new to RC aircrafts, and m very much interested in making a 1:12th scale SR71 using balsa wood.
   Please let me know :
      how can I make a A4 size plan to 1:12th scale plan ?
      Store where can I find balsa wood in Mumbai or online ?
      How many sheets of balsa will I require ?

Thanks,
     

Welcome onboard nit23s.. very ambitious to say the least, SR71!

Scaling a plan, the easiest way is using a graph paper, and the novel idea would be through a cad drawing. Balsa can be found in various online shops, like rcbazaar.com, rcproduct.in, etc. good luck..

@nit23s,
SR71 in 1/12 scale
9 ft long, 55" span, 12.5 sqft wing area.
Needs many thousands of Rs worth of balsa.

If this is your first model, one word of advice:
DONT.
But if you must,
Send a pm to gajjark (ahmedabad). He usually has balsa. Good rate, excellent packing.

Better idea - try it in depron. Easier and much cheaper. Large sheets instead of sticking 3" sheets of balsa together.

(BTW what power plant are you planning to use?)
Best of luck.

http://www.rcindia.org/rc-general-topics/converting-plans-to-tiled-plans/

Hi!
Thanks for your reply, Yes this is my first model, so would like to take your advice and go for a 1:6th scale which is good enough. can you sugeest me a way to convert a plan to 1/6th sale.
I have the attached plan. is it good enough to start with.

oh dear.. the lower the scale difference you go, the bigger the model becomes. so its like you should be doing 1:24 for halving the 1:12 scale as you intended earlier. aaand, thanks for the plan

Thanks for that.
will go for 1:24th, but will this plan work.
Can u give me some idea about hw can i start?
Looking out for balsa from rcbazaar.com.
There are many sizes available, which one to go for ?

before you dive into the balsa sizes..its better to decide what electronics you want to use..

Well sir building is a different thing and flying it is another. if u don't ve any prior experience of flying a plane then it ll be really difficult to save your precious model. if you are new to flying then I would suggest you to rather go for a trainer.

Hi,
  Planning for 4 Powerful Brushless 4300KV motor 64mm EDF's, 6 Channel Transmitter and Receiver, Servos, ESC's. The plane will be flown by a experienced personnel, so no problem with that.

Well..... SR 71.... no way.... it may well end up as a museum piece at your home and you may not want to fly it.  The fear of flying it is obvious.... the plane will fly fast.... real fast......  I am sure not many in your city will be able to handle it.  Secondly it will need something of a small runway and a good clear patch to make its approach for the landing. 

Its a bit of a highly ambitious project. 

My advice..... if you want to enjoy the hobby and fly yourself....... go for something which you can fly yourself...... start with a slower model and then graduate to a faster one.

Best Wishes.

  sample

Agreeing no more with Shobhit Sir would also like to point out the picture you posted is no plan but merely a photographs of cross sections from all dimensions. you would need balsa cutout plans to proceed further.

Hi,

  Please can anyone provide me the balsa cutout plans for SR71 or any idea about how can i get it, need to start working on it.

Thanks.

Get some depron and basic electronics, build a simple high winger/trainer from plans, like the Blue Baby or some FT swapables. You'll understand what it really takes to build a flight worthy model and if you still see the SR71 flame burning inside you, then you might be ready to build it.

Remember, you can't make biriyani without knowing how to cook rice.

It is like learning to drive on a Bugatti Veyron.

Thanks for your thoughts,
   Need solutions rather than faults. 

@nit23s,
Looks like you misunderstood well intentioned advice.
That being as it may, here are the plans and a construction article for a 38" span SR 71 in balsa and ply.
Includes list of materials required.
It's for a glow engine, but you could convert it to electric.

http://www.outerzone.co.uk/plan_details.asp?ID=6111

where can i find good b-cut 3mm balsa sheets in mumbai?