and the voltage you use..

Motor is matched to the
(a) pitch and length of the prop viv-a-vis the voltage it uses to rotate the prop (Basically the rpm at which it spins, which depends on the voltage it uses)

(b)below the design prop it will over rev and cause damage and under perform

(c) above the design prop the torque on the motor will be high and it will over heat.

that is in a nutshell

design props are given in the manual for the motor

there are 'WideCut' motors like the Hoffman Magnetics which works with wide variety of props, voltage and different prop at the same voltage.

its like i am buying the motor and the prop separately....and from the shop where i checked for it...he is not giving any manual or so with the motor.... ..

which motor is this, may be we can help

Brother...i havent yet bought it....can u just give me the thumb rules so that i can decide it for myself as in which motor would suit my motor..as of now i have bought a 8x6 prop and i dont know which motor would suit my purpose..so if you cud just guide me ....

Merged with existing thread about propellers. Please search before posting, most questions have be asked and answered before. Dont forget to visit the "Beginners... Start Here" at the top of the forum. Welcome to RcIndia

Guys,
While on the props, one thing that I come across in many of the western forums is the concept of prop balancing. While I understand the concept, I would like answers to the following questions
1) Is there a difference in flying characteristics if the prop is not balanced
2) How do we differentiate between a slightly bent shaft/collet and a unbalanced prop?

regards
Pankaj

Have a look here

http://www.rcindia.org/electric-planes/scratch-building-a-look-alike-of-axn-floater-or-fms-800-or-easystar/msg108670/#msg108670

Quote from: PankajC on September 18, 2012, 12:12:43 PM
2) How do we differentiate between a slightly bent shaft/collet and a unbalanced prop?

I think visual inspection is the only way, run the motor without prop and look a the tip of the shaft from the front 

@sls. The problem often is that it is very difficult to visually determine if a 3-4 mm shaft is off by a few degrees. Then with the collet & prop fitted it becomes difficult to isolate

@rastsaurabh. The info is about balancing a prop. My question was different

Quote from: PankajC on September 18, 2012, 08:03:45 PM
it is very difficult to visually determine if a 3-4 mm shaft is off by a few degrees

Its easy if you look at face of the shaft. PFA image. If it cannot be determined from this angle then may be its not that bad.

I am beginner to RC .
Can you brief me about the pitch of a propeller .I am thinking that more the propeller pitch more distance it can travel in one round.Is that correct? if not enlighten me.

THANK YOU.
  KRISHNA

yes correct.

Imagine it as a screw in air....

But the right selection of MOTOR , BATTERY , PROP combination is the Key for Thrust to weight ratio.

The basics of a propellor are its diameter and its pitch. The role of the diameter is to provide thrust and the role of the pitch is to provide speed. Both pitch and diameter has a direct link to the size of the motor/engine and its available RPM at wide open throttle (full throttle).

The RPM of a motor will change when a prop diameter and pitch is changed so it will result in change of thrust, change of speed and the amount of fuel/battery power it needs to continue to spin. Bigger diameter props with less pitch will give you slow flying with more thrust available while smaller diameter and more pitch will give you more speed and will consume more fuel or battery power.

Propellor pitch and diameter alone can't be a measuring tool to suggest how much distance you can travel in a plane without knowing the size of the engine/motor it has, the amount of fuel or battery size it is carrying, the amount of weight it's needs carry and the amount of drag it needs to fight with.

What is the project and what do you want to achieve?

Did I make it complicated? Think about a 100CC motorcycle with one liter of petrol in it and see how much kilometer it will travel with one person or two persons sitting on it. Also add the type of road it needs to travel, and how fast and slow you want to run it. General perception is that the faster you run an engine or electric motor, the more fuel or battery power you will consume.