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Help, need a large, low kV motor.

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Old 03-23-2012, 05:35 AM
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AmishWarlord
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Default RE: Help, need a large, low kV motor.

Don't forget about the other motor.
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Old 03-23-2012, 06:08 AM
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Default RE: Help, need a large, low kV motor.

I've got a 65-70 motor that I was going to use in a giant stick but those four, 4,000mAh 5s packs just cost too much for me to fly as much as I want to fly. 55cc gaser even beat out my G4500's.
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Old 03-23-2012, 10:23 AM
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Default RE: Help, need a large, low kV motor.


ORIGINAL: AmishWarlord

They have some 80-50 50cc class motors in stock

http://www.hobbyking.com/hobbyking/s...ner_Motor.html
Holy crap! Sorry about that but 5.3 KW? My how electric flight has change
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Old 03-23-2012, 11:02 AM
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Default RE: Help, need a large, low kV motor.


ORIGINAL: AmishWarlord

I've got a 65-70 motor that I was going to use in a giant stick but those four, 4,000mAh 5s packs just cost too much for me to fly as much as I want to fly. 55cc gaser even beat out my G4500's.
I am using 8 or 10 cells in my Gian Stick. Actually with 8 cells it is overpowered (19-10 prop). With 10 cells the power is obscene, and you can do VTO, unlimited vertical. I use 4 cell packs (2x4) or 1 6 cell and one 4cell. The motor is from Hobby Partz ($47). A blast to fly... Most of the time I just use 2x4. No way you would need more than 10. Actually maybe 9 would be perfection...

Gerry
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Old 03-23-2012, 11:13 AM
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Default RE: Help, need a large, low kV motor.


ORIGINAL: AmishWarlord

Well Gerry, price 10,000 mAh at 12s for me.

Wow, do you really need 10,000? I am using 5000 cells with a lot of success (so I am thinking of the price of the 5000, sorry)... I use a 1.6 motor with 19-10 prop. I am happy with the duration of the flights:-)

I guess it is a delicate balance of a series of factors. a) do you need that much juice (10000 ma, is a weight issue), and b) do you really need 12 cells? Using less cells would allow you to use a bigger prop (provided you still make enough power).

The power I get of this $47 motor from hobby partz is amazing. I just got MA and there is a nice article about a powerful charger and power source for big cell users.

Gerry

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Old 03-23-2012, 11:19 PM
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Default RE: Help, need a large, low kV motor.

Wow, do you really need 10,000?

I think you do it you want to swing two 24X16 4-blade props
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Old 03-25-2012, 12:18 PM
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Default RE: Help, need a large, low kV motor.

 Hi all, I have been watching HobbyPartz,Hobbyking,Nitroplanz etc...  For Tacon, Exceed monster and such, all are "out of stock" . Seems to me all of their stock is depleated and not being restocked. Also, any experiences with these motors would be helpful. I am building Top Flight 1/6 gold  editition P51 kit that will be FAST ELECTRIC.                                      
                                                                                                                                       
                                                                                                                                                                    Thank,
                                                                                                                                                                     Eric.
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Old 03-25-2012, 01:27 PM
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Default RE: Help, need a large, low kV motor.

1/6 is kind of small with the motors that we are talking about here.


But here goes.

You say fast. So your willing to trade flight duration for speed correct?

You'd rather fly 100 MPH for 2 mins than 65 MPH for 6 mins correct?

So we'll take 200 watts per pound.

Your goal weight is going to be 23 pounds.

23 x 200 is a 4,600 watt system

now take 4,600 watts and divide by 3. This gives you a motor weight in grams that can handle that many wants and not run hot.

4,600 w ÷ 3 = 1,533 grams

Lets just look at Great Planes Rimfire motors.

There 65cc motors weights 1,480g which within a 53g range and they claim that the motor can handle 6,500 watts.

OK the motor is rated at 160kv -20% loss we get 128kv

The 65cc motor will take a 15S pack. 55.5 volts

55.5 volts should give us 7,104 RPM

7,104 RPM on a 20X16 MENZ 2-blade wood prop will give,

21.6 pounds of thrust
a prop speed of 107 MPH
4,585 watts
82.6 amps
a 2.5 min run will cost you 3,440 mAh
+20% reserve = 4,128mAh
so you need three 5S 4,200mAh packs.
and a HV 100A ESC

Now you have a 100+ MPH Electric Mustang







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