how many cells do i need for my astro cobalt motor?
02-03-2003, 02:52 AM
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how many cells do i need for my astro cobalt motor?
how many cells do i need for my astro cobalt motor? ok i am new to electric i just got a p 39 that was setup for electric i need to know what would be the best setup to use . the moter is a astro-40
challenger cobalt motor i was thinking about 23 c cells at 3000 mah would that be enough really need help here.
thanks
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challenger cobalt motor i was thinking about 23 c cells at 3000 mah would that be enough really need help here.
thanks
[email protected]
02-04-2003, 03:05 AM
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how many cells do i need for my astro cobalt motor?
I would recommend that you call Kirk Massey at New Creations to ask the question...he is most helpful to folks. 936-856-4630
W. Stewart Tittle
W. Stewart Tittle
02-06-2003, 12:11 AM
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how many cells do i need for my astro cobalt motor?
Can you please post more info on the plane please?? Is the astro geard or direct drive?? what does the plane weigh? Is this the P39 from top flight?? Does it have landing gear ? or is it a hand launch? Here are a couple rules of thumb,If this is the fighter plane you'll need 75watts per pound to rise off ground.Another thing I always check is static thrust.If the plane weighed 8lbs I would want AT LEAST 3.5LBS of static thrust.I check this by tieing the tail to a fishing scale that is anchord to the ground.With the batteries topped off push the throttle to "WIDE OPEN!!"and read the scale. Do you have a "ASTRO WATT METER" I f no, then go buy yourself one!. Here is a good program to calculate a planes performance,www.motocalc.com they even offer a FREE 30 day trial.Good luck,stefanP 
02-23-2003, 05:09 AM
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how many cells do i need for my astro cobalt motor?
You also need to know if is a F.A.I. wind motor. The regular 40 is good to about 24 cells. The FAI is around 10 cells, if memory serves me! Look up astro flight or Leasure Electronics for references. I am going with a 40 geared turning a 18/8 prop 21 cells. This is for a 60" Fokker Triplane.
Frank
Frank
04-15-2003, 09:42 PM
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how many cells do i need for my astro cobalt motor?
Yard you need to know if the astro motor is a standerd cobalt or FAI motor.I used a regular astro geard 40(which is a 1:68 to 1 ratio)on 16 cells.APC 13/8"E" prop @28 amps =560 watts. If you have a "Astro SUPER BOX" this is a 3to1 ratio so it will let you swing very large props as frank mentioned.Your plane is a fighter plane so I would steer away from a super box.Also standerd astro motors are good for 35amp static draw and there best efficent at around 25amps.A 13X8 APC-E prop with 20 cells will give you 840 watts drawing 34amps static. Good luck,stefanP
