RC India

RC Equipments => Electric Power => Topic started by: khan007 on January 16, 2014, 04:46:21 PM

Title: prop size help
Post by: khan007 on January 16, 2014, 04:46:21 PM
friends what prop size do u sujest for 800g electric plane(suggest me the motor's kv too)
Title: Re: prop size help
Post by: Nithinraj Kotian on January 16, 2014, 05:29:53 PM
Emax CF2822 1200KV  prop: 9*5, 10*5
Title: Re: prop size help
Post by: utkarshg13 on January 16, 2014, 05:35:47 PM
Try out this link:
http://www.rcdhamaka.com/index.php?main_page=product_info&cPath=100_93&products_id=391 (http://www.rcdhamaka.com/index.php?main_page=product_info&cPath=100_93&products_id=391)
:hatsoff:
Title: Re: prop size help
Post by: khan007 on January 16, 2014, 05:54:08 PM
how about a 1450 kv motor and 7*4 inch
Title: Re: prop size help
Post by: khan007 on January 16, 2014, 05:55:45 PM
will be 1450kv and 7.3 effective
Title: Re: prop size help
Post by: Nithinraj Kotian on January 16, 2014, 06:00:22 PM
go for 8x6 slow fly prop.
Title: Re: prop size help
Post by: manojswizera on January 16, 2014, 06:07:04 PM
Instead of going for 1450 kv.
go with CF2822-1200 kv and 9inch prop.
Title: Re: prop size help
Post by: Nithinraj Kotian on January 16, 2014, 06:17:25 PM
@swizera: he already brought 1450kv motor i guess  :headscratch:
Title: Re: prop size help
Post by: manojswizera on January 16, 2014, 06:24:38 PM
If he already bought , then its his wish  :)
I doubt that motor can give enough thrust .
Title: Re: prop size help
Post by: khan007 on January 16, 2014, 06:36:05 PM
any possibility to increase trust ?like increasing the prop size
Title: Re: prop size help
Post by: khan007 on January 16, 2014, 06:38:49 PM
i mean without changing the 1450kv motor
Title: Re: prop size help
Post by: khan007 on January 16, 2014, 06:42:20 PM
i got a 1450kv motor and 8.4 inch prop.does it can give me enough trust to lift 800gm weight
Title: Re: prop size help
Post by: khan007 on January 16, 2014, 06:49:29 PM
help me pls
Title: Re: prop size help
Post by: Nithinraj Kotian on January 16, 2014, 06:54:57 PM
sell your 1450kv motor and buy Emax 1200kv motor from Rcdhamaka.  :hatsoff:
Title: Re: prop size help
Post by: rastsaurabh on January 16, 2014, 07:02:30 PM
Battery is 2S or 3S ??
Title: Re: prop size help
Post by: khan007 on January 16, 2014, 07:04:38 PM
any more ideas
Title: Re:
Post by: docnayeem on January 16, 2014, 07:05:41 PM
Khan007 firstly ... Know the model ... Is it a glider ? Scale ? Jet ? 3D .... This will decide what thrust and what speed is required to keep it airborne ... And then finalize the power config ...
Title: Re: prop size help
Post by: manojswizera on January 16, 2014, 07:07:13 PM
Khan , you have place order or you have it with you.
If you have just place order than , you can request them to change as they cost same.

If you had it with you , then no choice , make smaller plane with weight less than 500 gm and use on it.

If you really want good thrust of nearly 800 gm than go with other motor. CF2822 will also not give you 800 gm thrust , but can fly your plane.
Title: Re: prop size help
Post by: khan007 on January 16, 2014, 07:07:25 PM
its a 2200 mah 3s battery
Title: Re:
Post by: docnayeem on January 16, 2014, 07:16:27 PM
Like for a 800 gms  jet u will need a small prop is it has high wing loading and needs speed more than thrust to keep it air borne ..on the other hand if its something Like a slow stick u will need thrust and not speed so need a bigger prop ... And all this will dictate the motor battery ....
Title: Re: prop size help
Post by: khan007 on January 16, 2014, 07:29:13 PM
this the plane photo 36inch wing span
Title: Re:
Post by: docnayeem on January 16, 2014, 07:33:15 PM
Done this from some plan ? Wings don't seem to have aerofoil so won't have lift not a it will be tough getting it airborne as will require a large high pitch prop coz its only speed thats going to keep at aloft ..... Correct me if I am wrong ....
Title: Re: prop size help
Post by: khan007 on January 16, 2014, 07:38:06 PM
it got aerofoil wing
Title: Re: prop size help
Post by: khan007 on January 16, 2014, 07:43:28 PM
but its made from aluminium rod ,and coro plastic board,thats why it look like that
Title: Re: prop size help
Post by: utkarshg13 on January 16, 2014, 07:47:58 PM
This model is similar to Moss glider model i build. Only the wingspan is different. Mine was around 40" and wasn't having airfoil shape. I used 1200KV motor for it with 20A ESC and a 2S 1000mAh battery and GWS 9X5 prop.
I don't know why your model is so heavy... 800gm... since, it seems to be a slowstick...
Title: Re: prop size help
Post by: utkarshg13 on January 16, 2014, 07:49:51 PM
I too used coroplast for wingspan and carbon fibre rod of 12mm square cross section. AUW of my model was approx. 500gm... Not above...
:hatsoff:
Title: Re: prop size help
Post by: manojswizera on January 16, 2014, 07:52:54 PM
just my sujjestion.
you can add small 7 -8 inch dihedral, on both sides. That will increase the wing area, and will glide more. will also need less power, increase stability.
Title: Re: prop size help
Post by: khan007 on January 16, 2014, 07:53:36 PM
bro the coro board is so flexible so i used some wooden rods-taken from coconut plant -and the battery is 2200mah battery.the total aeroplane weight is around 700g
Title: Re: prop size help
Post by: khan007 on January 16, 2014, 07:59:59 PM
does that means i need to bend by fuselogue
Title: Re: prop size help
Post by: utkarshg13 on January 16, 2014, 08:00:30 PM
After adding these rods i am sure your wing would flutter... adding some dihedral would definitely give a good glide and adds to stability as well...  
Title: Re: prop size help
Post by: khan007 on January 16, 2014, 08:02:46 PM
how to add dihedral on my wings
Title: Re: prop size help
Post by: khan007 on January 16, 2014, 08:03:34 PM
i dont know anything about dihedral
Title: Re: prop size help
Post by: utkarshg13 on January 16, 2014, 08:05:18 PM
Adding a pic
Title: Re: prop size help
Post by: khan007 on January 16, 2014, 08:12:31 PM
nice
Title: Re: prop size help
Post by: utkarshg13 on January 16, 2014, 08:16:03 PM
I hope now its fine with you... This model flies very nicely... :thumbsup:
Title: Re:
Post by: docnayeem on January 16, 2014, 08:17:12 PM
@utkarshg 13 ... I agree a poly dihedral will add to stability and will also decrease wing loading
Title: Re:
Post by: docnayeem on January 16, 2014, 08:17:48 PM
Go ahead Mr. Khan ....
Title: Re:
Post by: docnayeem on January 16, 2014, 08:19:45 PM
One more thing I would suggest is don't use coconut sticks ... Cf rods are ideal ... But if not use plastic electrical casing cover it works best and is light
Title: Re: prop size help
Post by: utkarshg13 on January 16, 2014, 08:38:23 PM
Plastic casings.... :thumbsup: :thumbsup: :thumbsup: good idea. Even i would use these...
:hatsoff:
I think balsa sticks could also be used and are much cheap. Available on Rcbazaar...
Title: Re:
Post by: docnayeem on January 17, 2014, 09:31:30 AM
Balsa sticks are expensive compared to these electrical casing ... One more thing which I use is pine wood sticks u can get those cut in 4 mm  and 6 mm from a saw mill if u have any close by ... Even those are light and tough ...
Title: Re: prop size help
Post by: Nithinraj Kotian on January 17, 2014, 10:29:25 AM
or you can use light wooden corner beading's which are easily available in local hardware shop. :hatsoff:
Title: Re:
Post by: docnayeem on January 17, 2014, 10:39:47 AM
So back to your question mr khan .... If u can reduce the weight if not let's see about power config...
Let's say we give 1:1 thrust so we need around 800 gms  of thrust ... Let me see what u have ....
.
Title: Re: prop size help
Post by: manojswizera on January 17, 2014, 10:43:10 AM
Quote from: khan007 on January 16, 2014, 08:02:46 PM
how to add dihedral on my wings
Cut 7 inch coro sheets with same chord as your wings. Take small 4 pieces of cycle spokes approx 5 cm. Bend them at an angle, you need for your dihedral.
insert the spoke in coro flute at the leading and trailing edge of your wing, fix it will CA.
put the other end in dihedral part of coro, fix again with CA.  

Call if u didn't get clear.
7768069805
Title: Re:
Post by: docnayeem on January 17, 2014, 10:44:22 AM
You have a 1450 kV motor I guess its emax and two cell ( please specify ) if its two cell then 8*4 prop that u have and this motor will hardly give y a thrust of around 500 gms ... Its is OK but might not be sufficient if its a 3 cell motor then we will get a thrust of 1.8 kgs  that's great enough ...
Title: Re: prop size help
Post by: rcrcnitesh on January 17, 2014, 02:08:00 PM
which 1450kv motor ???
Title: Re: prop size help
Post by: khan007 on January 18, 2014, 12:41:42 AM
Mystery A2208-14 1450kv
Brushless Outrunner Motor