Hi Experts,

I have plans to make a cardboard based airplane. The expected weight of the final assembled device will be around 400-600 grams.
The airplane will fly only straight and in a circular path(tied with a cord to a center point i.e. NO radio control and servos and ESCs).

I looked around to get an idea of a powerful motor which can generate enough thrust for this device for a good flight. I got this link http://rcbazaar.com/products/159-odin-3800kv-brushless-motor-for-450-size-helis.aspx which talks about a powerful motor.
This motor is said to be capable of generating a power of upto 380 Watts. The motor weighs around 65 grams. The motor is supposed to be used in a 450 type helicopter. The reason I am interested in this motor is its cost?

Could you please clarify the below for me:
1) Can I use this motor in my airplane(which is not a helicopter)? If yes then what propeller and battery should I be using considering the final weight of the assembly?
2) What should be the wingspan of my airplane keeping in view the weight of the total device and motor power?
3) Apart from battery and motor, what else I might need for making my airplane work?
4) Any other inputs will be appreciated.

Thanks,
Nadia.

Cardboard i'm not sure, foam or coro will better. The motor you have pointed to is not suitable for three reasons 1)its a very high kv motor not suitable for direct drive 2) you'll need an esc to run it 3) very expensive for what you are trying to do.
A speed 400 brushed motor should be good enough and aim for weight less than 300 grams.
Also read this for some ideas:
http://www.rcgroups.com/forums/showthread.php?t=229024

Welcome to RcIndia, do read through "Beginners... Start Here" link at the top.

why don't you try to setup electric power on control line model? in fact i also started working on airplane "without RADIO" and so i choose control line before more than an year(pity-not giving dedication)...I'm trying something like bluebird (24" span), yet not complted  

Quote from: SunLikeStar on December 05, 2011, 02:41:21 PM
A speed 400 brushed motor should be good enough and aim for weight less than 300 grams.

Thanks for the reply.
Where do I buy speed 400 motor from? Any online store/link..

Quote from: PiyushI on December 05, 2011, 03:28:21 PM
why don't you try to setup electric power on control line model? in fact i also started working on airplane "without RADIO" and so i choose control line before more than an year(pity-not giving dedication)...I'm trying something like bluebird (24" span), yet not complted 

do you mean your batteries are not on-board?
What material have you used for making the plane's body?

@nadia
its soft balsa wing with hard balsa fuselase... as you said, "plan" for battery is not on-bord, but yet not finished

Quote from: PiyushI on December 05, 2011, 03:50:13 PM
@nadia
its soft balsa wing with hard balsa fuselase... as you said, "plan" for battery is not on-bord, but yet not finished

can i see a pic of it?

Quote from: nadia on December 05, 2011, 03:43:04 PM
Where do I buy speed 400 motor from? Any online store/link..

You can use this motor with a 3s lipo.
http://robokits.co.in/shop/index.php?main_page=product_info&cPath=2&products_id=208&zenid=ea772bafa630081cb6e28216c52c99f5
If you want to be able to switch the motor on/off while flying then you'll have to connect a relay between the motor and lipo. keep the lipo on the plane and power supply for relay in your hand. I think robokits.co.in have relays also.
Or you can have a cutoff circuit between the motor and lipo which will switch your motor off when the voltage is below 10v and you can land your plane.

[Admin Note] Unwanted "Quote" removed... use "Reply" instead... See usage guidelines : http://www.rcindia.org/rc-india-forum/forum-usage-tips/

Any idea about the weight of the motor?
I am planning to go for this battery
http://robokits.co.in/shop/index.php?main_page=product_info&cPath=13&products_id=68&zenid=ea772bafa630081cb6e28216c52c99f5
Would this battery be ok?

70 - 80 grams may be but i'm just guessing, better contact the vendor about it.
Have no idea about lion batteries so cant comment on that. Any ways it says 1C discharge which is too low for running a motor. you should get a 3s lipo, 350 or 500 mAh.

Thanks for the inputs.

I am a little confused about the battery. The battery and charger pair is one component which is somewhat expensive.

I will surely be trying more powerful motor in the future. Keeping this in mind, which battery should I go for so that I dont have to buy a battery pack again when I replace the motor?

Thanks,
Nadia.

I got a reply from the vendor about the motor:

1) The motor is an in-runner 12V DC and does not come with a propeller adapter. I need to buy a propeller and an adapter for that. I have never bought one before. Could you guys give me some link where I can order the propeller, adapter and related stuff? The spec of the motor says that the shaft has a diameter of about 2.3 - 2.5mm.

2) I saw a few posts on this forum and noticed that an in-runner motor may need a gearbox!! Will I need a gearbox too(for auw of 300 gms)? If so then which one should I buy? Link please if possible 

Thanks.
Nadia.

Thanks for the inputs experts.

I have ordered  this motor http://robokits.co.in/shop/index.php?main_page=product_info&cPath=2&products_id=208&zenid=ea772bafa630081cb6e28216c52c99f5.

1)I spoke to the vendor who said that I will need to buy propeller adapter for this. Could you guys advise which one should I go for?
2)Which propeller should I go for if the expected auw of my plane is 300-350 gms.
3) Will I need gearbox as well? If yes then which one?

Thanks.
Nadia.

Moderator note: Merged with your existing thread, please keep all discussion related to this project in the same thread for the sake of continuity.

The diagram on your motors page clearly states the shaft size is 2.3mm so that's the adapter you need. Get a 5x4 prop and you wont need a gearbox. There are lots of hobby shops you can buy these stuff from including lipo and charger. For the list of shops check the "Mega list of all RC outlets in India" thread.
ps: here is a suitable adapter
http://www.rcbazaar.com/products/247-23mm-jj-prop-adapter.aspx

I'm confused on few things since original post called for No RC
1) without Rx how will the esc power up the motor?
2) how does the material, being cardboard, provide shock absorbing capabilities to cushion the lipo and motor in a not-so-perfect contact with the ground?

Pankaj, its a control line model, no Rx and no esc. Check out the link in posted in reply #1.

Pankaj,

My fuselage will be made of light cardboard. I will surely place a supporting foam around the battery and motor so that nothings breaks(hopefully) in case of crash landing.

Anyways, I chose cardboard just because this is my first project and I want it to be as cost effective as possible. The first of mine is going to be a TEST ONLY model(understanding of concepts).  If the test flight goes somewhat ok, the next project will be to prepare a new model with esc, motor, servos and radio control.

But for me the first big thing is to see this light-cardboard plane flying using control-line. 

Cheers.

@SLS, didn't know that we could connect motor directly to the battery hence the question about Rx and ESC (still don't know about speed 400 though)

missed on this topic as it read, cardboard plane.....

regarding the c/l (control line) plane the motor you are suggesting is a 3 TREMINAL motor (3phase  AC), all brushless motor are the same, and the batteries we get to power the motor are 2 terminal (DC), hence we need the ESC to convert it as well as to control the speed. ( same as the throttle servo on a glow plane)

getting into C/L will be highly appreciated by me.. any help will be supported to u as best as i can from my side.

classically CL has to have a engine with specific amt of fuel in the tank which will decide the flight time. and you will have no throttle control.

but since your idea is of electric. you can go ahead with it also.  all you will need now is a DC motor/ brushed motor which will act as ur engine  and a small capacity battery which will act as your tank. keep the battery capacity less or you will end up turning whole day.

and for the control of a control line :
CL has only one axis controllable i.e pitch, as it circles you it has no turning (roll or pitch)
you will need two lines in your hand one for up throw and one for down ( understand form the drw below) which will be connected to your handle . pulling one line will make the nose pitch up and other pitch down.

whn you pull line1 the elevator pitches up, and line 2 pitches down (connect pushrod to a control horn to the bottom side of the elevator..!) pic of handle also enclosed.)
hope u can understand the pic.... any quries are most welcomed .. ( my ph no is  in my signature)

Quote from: R/C vish on December 09, 2011, 04:19:38 PM
the motor you are suggesting is a 3 TREMINAL motor (3phase  AC), all brushless motor are the same, and the batteries we get to power the motor are 2 terminal (DC), hence we need the ESC to convert it as well as to control the speed.

Please read the complete thread, the motor we are talking about now is a 12v DC brushed motor.

sorry missed on that... any ways for rest all it looks good.!

I have looked on rcbazaar and robokits but still not able to find a suitable li-po battery for my motor.
could you guys provide some online link where I can order this battery? I am looking for a lightweight battery.

this can be used..!
http://www.hobbyking.com/hobbyking/store/__7292__Rhino_750mAh_3S_11_1v_20C_Lipoly_Pack.html

I received the motor yesterday through courier. To my surprise the weight of the motor is nowhere near to what the vendor claimed.

The actual weight is around 125-140 grams. A big challenge now for me is to keep the auw of my plane to a minimum.

If the motor and battery assembly itself weighs more than 200 grams then its difficult to keep the auw to be less than 400gm(this is the min I am assuming). I have no prior knowledge of aerodynamics. Can experts please advise me about:
1) How much the wingspan & wing-area should be
2) What should be the length of the fuselage?


Thanks for the help guys.

Hi,

At the moment my project is a control line-one but I would like to promote it to wireless radio once it is working.

1)I would like to go for the cheapest radio controller and recievers. Could you guys please guide me about this?

2)Also, I am a total newbie to flying. How can I get access to a simulator to learn flying?


Thanks.