lipo packs & prop selection
08-25-2008, 08:39 AM
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lipo packs & prop selection
Hi Everyone
I have a question on which lipo battery should I use on an airplane I have.
The plane is a Lil Rascal with 30" wingspan, 10 oz. flying weight, 28-26-1000 rimfire outrunner brushless motor, 12 amp silver series ESC. The stock motor on this plane is a 180 size brushed & geared motor and comes with a 6" propeller that makes the plane look scale.
Since the new motor has a lot of more power than stock motor I'm concerned with torque. The new motor turns 1000 revolutions per volt so I'm inclined on using a 7.4 volts pack and I'm willing to increase prop size to a maximum of 7"X6" to deal with power & torque.
What pros/cons 7.4v & 11.1v have (aside from weight & size) and which lipo pack (2c or 3c) do you suggest for this setup?
Which size & type (slow flyer, APC or GWS orange type) do you suggest for this setup?
Any help will be appreciated,
I have a question on which lipo battery should I use on an airplane I have.
The plane is a Lil Rascal with 30" wingspan, 10 oz. flying weight, 28-26-1000 rimfire outrunner brushless motor, 12 amp silver series ESC. The stock motor on this plane is a 180 size brushed & geared motor and comes with a 6" propeller that makes the plane look scale.
Since the new motor has a lot of more power than stock motor I'm concerned with torque. The new motor turns 1000 revolutions per volt so I'm inclined on using a 7.4 volts pack and I'm willing to increase prop size to a maximum of 7"X6" to deal with power & torque.
What pros/cons 7.4v & 11.1v have (aside from weight & size) and which lipo pack (2c or 3c) do you suggest for this setup?
Which size & type (slow flyer, APC or GWS orange type) do you suggest for this setup?
Any help will be appreciated,
08-25-2008, 11:08 AM
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RE: lipo packs & prop selection
prflyer
Go back to the motor manufacturer's specs and start there with the recommended prop size. Even check that with a watt meeter to be sure you are drawing less than the controllers maximum. If you don't have a watt meeter, quit flying until you do. It's about as necessary as a prop. Battery, a 3c is going to give you more performance and duration compaired to a 2cell. Lil Rascal is a sweet flying sport bird with limited airobatic ability, high lift wing. You should be able to carry a 1320 or so battery. Any battery you buy today should be capable of 20C if its not old shop stock. I have been buying my batteries from United Hobbies for the past several months based on a flying buddy's experience of more than a year with the Zippy 20-30C and higher quality Polly Quest. My experience for 3-4 months has been also good. Get the same flying time (3D) as with my Thunderpower and max amp cells for about 1/2 the price. No bad experiences to report. Have ordered on a Friday and received order on Monday. Don't know how that one was done, but true, usually a week. Better than some USA shops. ENJOY
Go back to the motor manufacturer's specs and start there with the recommended prop size. Even check that with a watt meeter to be sure you are drawing less than the controllers maximum. If you don't have a watt meeter, quit flying until you do. It's about as necessary as a prop. Battery, a 3c is going to give you more performance and duration compaired to a 2cell. Lil Rascal is a sweet flying sport bird with limited airobatic ability, high lift wing. You should be able to carry a 1320 or so battery. Any battery you buy today should be capable of 20C if its not old shop stock. I have been buying my batteries from United Hobbies for the past several months based on a flying buddy's experience of more than a year with the Zippy 20-30C and higher quality Polly Quest. My experience for 3-4 months has been also good. Get the same flying time (3D) as with my Thunderpower and max amp cells for about 1/2 the price. No bad experiences to report. Have ordered on a Friday and received order on Monday. Don't know how that one was done, but true, usually a week. Better than some USA shops. ENJOY
09-01-2008, 07:03 PM
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RE: lipo packs & prop selection
ORIGINAL: prflyer
Hi Everyone
I have a question on which lipo battery should I use on an airplane I have.
The plane is a Lil Rascal with 30" wingspan, 10 oz. flying weight, 28-26-1000 rimfire outrunner brushless motor, 12 amp silver series ESC. The stock motor on this plane is a 180 size brushed & geared motor and comes with a 6" propeller that makes the plane look scale.
Since the new motor has a lot of more power than stock motor I'm concerned with torque. The new motor turns 1000 revolutions per volt so I'm inclined on using a 7.4 volts pack and I'm willing to increase prop size to a maximum of 7"X6" to deal with power & torque.
What pros/cons 7.4v & 11.1v have (aside from weight & size) and which lipo pack (2c or 3c) do you suggest for this setup?
Which size & type (slow flyer, APC or GWS orange type) do you suggest for this setup?
Any help will be appreciated,
Hi Everyone
I have a question on which lipo battery should I use on an airplane I have.
The plane is a Lil Rascal with 30" wingspan, 10 oz. flying weight, 28-26-1000 rimfire outrunner brushless motor, 12 amp silver series ESC. The stock motor on this plane is a 180 size brushed & geared motor and comes with a 6" propeller that makes the plane look scale.
Since the new motor has a lot of more power than stock motor I'm concerned with torque. The new motor turns 1000 revolutions per volt so I'm inclined on using a 7.4 volts pack and I'm willing to increase prop size to a maximum of 7"X6" to deal with power & torque.
What pros/cons 7.4v & 11.1v have (aside from weight & size) and which lipo pack (2c or 3c) do you suggest for this setup?
Which size & type (slow flyer, APC or GWS orange type) do you suggest for this setup?
Any help will be appreciated,
You need to balance battery voltage versus prop size (and keep the motor within its max amps/watts limits). Now that is a 1000Kv motor which is rated for 12A/135W continuous and 15A max. "surge". With such a low Kv you will HAVE to use 3s, otherwise you will need a ridiculously large prop to make the most of the motor. For 3s I would suggest a 10x6 GWS HD: my testing produced this: 10.9v, 10.35A, 112W, 6870rpm, 39.0mph, 673g, 23.70oz, 6.01g/W. A 10x4.7 AC SF drew just over 12A and the motor got VERY HOT, VERY FAST. I think their 15A max is pie in the sky!
On 3s you could be very tentative and use an 8x4 GWS HD, if a 10x6 GWS HD is too big for the plane, though an 8x4 would only draw 5.25A/57W and get you 14.68oz @ 33mph. I'd guess that a 7x6 on 3s would draw about the same.
If you were to use 2s and the 7x6 you mentioned, I doubt you'd draw more than 3A. To get anywhere near 12A draw on 2s you might need a 14" prop, and I can assure you that motor doesn't have enough torque to swing something that size [nor would you have any ground clearance]!
