How to find the right PROP?

Helifly · Dec 29, 2002, 01:12 AM

Is there a web site on how to find the right prop/gear ratio to use? I don't know planes like I know helicopters. I want to make sure I'm not pulling too many amps.... and have a prop for the best proformance.

I have The Champion and I'm looking to put a brushless motor in. Right now I have the Orion, I don't know what prop or gear ratio is right for the motor. Thanks a lot

touser · Dec 29, 2002, 01:35 AM

I was also wondering about this for a crazy 8 and a jeti 15/4 brushless. But if there is a website or some information out there that will teach me how to determine the best prop for the plane that would be great.

kmashima · Dec 29, 2002, 01:44 AM

You can use Motocalc or Ecalc to figure out the right prop. Most of us use APC- E (electric) props. They have the largest variety from small to very large. You can download from www.motocalc.com for 30 days free. You will need to program to tune your system. There are too many variables to do this by hand for a new plane. You have the plane config, motor, gearing, prop, battery type & number of cells.

The programs will let you experiement so that you will have the ability to NOT CRASH on your first flight. And you will have an expectation of how long your flight will be (approximately).

-- Kyle

GregG · Dec 29, 2002, 10:30 AM

Using one of the 'Calc programs is a great way to get things into prespective. They'll allow you virtually to try different cells, cell counts, props, and gear ratios. You can usually get the motor specs from the motor manufacturers web site to add to a 'calc program.

It also depends on the airframe style and the way you want to fly it. Sleek race type airframes get along best with around 1/1 diameter/pitch ratio. Aerobatic planes or those with a bit more drag like appox. 1.5/1 ratio. 3d airframes seem to like a 2/1 ratio.

Looking at the plane from the Hobby Lobby page your plane fits into one of the last two categories. They also have the nice looking carbon cased BL motors that would make a great replacement for the stock MIG 280 gear drive.

Dec 29, 2002, 01:12 AM	#1
Helifly Registered User Join Date: Jun 2002 Location: Palm Beach Posts: 63	How to find the right PROP? Is there a web site on how to find the right prop/gear ratio to use? I don't know planes like I know helicopters. I want to make sure I'm not pulling too many amps.... and have a prop for the best proformance. I have The Champion and I'm looking to put a brushless motor in. Right now I have the Orion, I don't know what prop or gear ratio is right for the motor. Thanks a lot

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Dec 29, 2002, 01:35 AM	#2
touser Registered User Join Date: Dec 2002 Posts: 8	I was also wondering about this for a crazy 8 and a jeti 15/4 brushless. But if there is a website or some information out there that will teach me how to determine the best prop for the plane that would be great.

Dec 29, 2002, 01:44 AM	#3
kmashima Registered User Join Date: Feb 2002 Location: San Jose, California, United States Posts: 2,128	You can use Motocalc or Ecalc to figure out the right prop. Most of us use APC- E (electric) props. They have the largest variety from small to very large. You can download from www.motocalc.com for 30 days free. You will need to program to tune your system. There are too many variables to do this by hand for a new plane. You have the plane config, motor, gearing, prop, battery type & number of cells. The programs will let you experiement so that you will have the ability to NOT CRASH on your first flight. And you will have an expectation of how long your flight will be (approximately). -- Kyle

Dec 29, 2002, 10:30 AM	#4
GregG Speed Demon Join Date: Dec 1999 Location: Antioch,CA,USA Posts: 11,390	Using one of the 'Calc programs is a great way to get things into prespective. They'll allow you virtually to try different cells, cell counts, props, and gear ratios. You can usually get the motor specs from the motor manufacturers web site to add to a 'calc program. It also depends on the airframe style and the way you want to fly it. Sleek race type airframes get along best with around 1/1 diameter/pitch ratio. Aerobatic planes or those with a bit more drag like appox. 1.5/1 ratio. 3d airframes seem to like a 2/1 ratio. Looking at the plane from the Hobby Lobby page your plane fits into one of the last two categories. They also have the nice looking carbon cased BL motors that would make a great replacement for the stock MIG 280 gear drive.