RC India

General Topics => Beginners Zone => Topic started by: agpraneet on July 01, 2013, 06:57:54 PM



Title: Need advice on a scratch built plane
Post by: agpraneet on July 01, 2013, 06:57:54 PM
Influenced by the plans for blubaby, we have tried to build a plane. We had a lightweight fuselage available, taken out from a wooden model. So decided to use that. So scaled the whole thing down to the fuselage size. So, the 42" wings are now 52 cms or 20". Now, the problem is we don't know if it can fly. If it can, can someone suggest the appropriate electronics. We are in this hobby for long and would prefer components that can be used afterwards as well. Like a 4 channel radio with sim etc.

Specs:
52 cms wingspan
flat bottomed aerofoil
chord length 10.5 cms
Material: Polystyrene (thermocole)
Total weight: 70gms

Thanks in advance

Pics: https://drive.google.com/folderview?id=0B7otepoRGh0QRHFWM3BkZVE1ZFk&usp=sharing


Title: Re: Need advice on a scratch built plane
Post by: kaarthic.r.b on July 01, 2013, 07:41:57 PM
9 gram servos:

http://www.rcbazaar.com/products/794-avionic-av9a-9g-servo.aspx

motor :

http://www.rcbazaar.com/products/1476-odin-2730-kv1300-thrust-440-gms.aspx

ESC:

http://www.rcbazaar.com/products/806-avionic-20amp.aspx

battery:

http://www.rcbazaar.com/products/1212-wolfpack-1000mah-20c-74v.aspx

Tx and Rx:

http://www.rcbazaar.com/products/1773-avionic-rcb7x-7ch-tx-with-7ch-rx-and-wireless-simulator.aspx


Title: Re: Need advice on a scratch built plane
Post by: kaarthic.r.b on July 01, 2013, 07:51:50 PM
If you want to know the result then fly it..... :giggle: :giggle:


Title: Re: Need advice on a scratch built plane
Post by: agpraneet on July 01, 2013, 08:15:42 PM
Thanks Karthic. I guess we will do that. Just wanted to know if he 20" wingspan with that weight can fly :-). Most of the plans are 40-42" models only

Thanks for the components. Can you explain how the brushless motor is selected? And can you suggest a cheaper tx/rx?


Title: Re: Need advice on a scratch built plane
Post by: kaarthic.r.b on July 01, 2013, 09:00:23 PM
6ch channel radio :

http://aeroworks.co.in/store/index.php?id_product=115&controller=product

you can select the motor depending  on weight of the plane


Title: Re: Need advice on a scratch built plane
Post by: agpraneet on July 24, 2013, 04:16:10 PM
okay. now that I have purchased the rx/tx (a 6 channel flysky ct6b), I am back to choosing a power system. What I am currently lookin at is

http://www.rcdhamaka.com/index.php?main_page=product_info&cPath=100_93&products_id=273

or the one suggested by kaarthik.

for the prop, I am thinking of a 8x6 prop after reading on the internet. And this is supposed to be a trainer. For the ESC, I plan to go with the one suggested by kaarthik

for the battery, i plan to use a 900mah battery to save on some weight.

http://www.rcbazaar.com/products/1737-wolfpack-900mah-20c-74v.aspx

I am looking for a go ahead for the above mentioned scratch build. Is it good to go?


Title: Re: Need advice on a scratch built plane
Post by: sanjayrai55 on July 24, 2013, 08:06:42 PM
I do not agree with your basic premise. A 20" span model is always difficult to fly. As a beginner you will have difficulty in all 3 x-y-z dimensions, and should have a large wingspan, the larger the better. Choose your equipment around this. The better quality equipment you get, the happier you will be. Don't go for cheapest.

I suggest for the first model buy a good kit, or enlist a very seasoned modeller to guide you. Keep it simple at first. Trust me, when you are in the air for the first time, your hands will be literally very full. The last thing you want is faulty equipment or a faulty model.

Don't be in a hurry to scratch-build. There will be plenty of time for that. First get familiar with the basic fundas, both of flying, and of a flying model's characteristics. If you must, go with a proven design, which is easy and uncomplicated .

Good luck!


Title: Re: Need advice on a scratch built plane
Post by: shauviks on July 25, 2013, 12:52:54 AM
+1 Sanjay sir
Definitely 20 inch wingspan is a very difficult plane to control.As a beginner i would suggest you to go for some tested begginer models like easy star 2 from RC Dhamaka or sky surfer from RC Bazaar.

Keep the scratch built model aside for a few days learn to fly in a trainer model. Get the experince then try a scratch built coz in scratch built model u will never come to know what went wrong and eventually u will loose interest in the hobby .........



Chheeeers


Title: Re: Need advice on a scratch built plane
Post by: PankajC on July 25, 2013, 01:38:29 PM
@Agpraneet - my few bits of information on scratch builds....

The plane with dimensions that you have posted already has a wing cubic loading close to 6 oz/cu-ft. as per the calculations available online. This is close to the limit of the loading necessary for glider category.

Do not power up, it will increase the wing loading e.g. even a 30 gm increase in wt would make the wing loading close to 9 which is somewhere in the range of acrobatic planes, further I do not think battery, motor, prop, receiver, servo all could ever total to under 30 gm...

At best use this as a chuck glider and enjoy your creation.