Some people I fly with say that it is not really needed to balance props (they usually come balanced from the factory, but after getting any cuts or nicks, they lose the balance).  

1) Do most people here worry about balancing their props ?  

2) How do you balance it ?

Ismail - Do you balance your props occassionally ?

As a heli flyer, I just get factory balanced main rotor blades.  We do apply weight stickers to further balance, if we feel significant stability/vibration issues. But for helis, 99% of the time the issue is the non-symmetrical setup of linkage rods on the head, causing one blade to rotate in a different plane than the other.

Normally, I do not. However, if I find excessive vibration then I check it. But it mostly gets resolved by giving a shave on the other end of the prop with a file. I just go with trial n error method.

This is just another myth evolved to sell stuff to modellers -
viz - prop balancers . If fact I would'nt be surprised if the
people who make prop balancers - have an understanding
with the prop manufacturers - to make deliberately unbalanced
props.

Facts:

1. you can never achieve perfect prop balance with
    an IC engine at all RPM ranges

2. electric motors run so smoothly that
    the negligible imbalance due to manufacturing will not
    make a difference.

And another thing - just to muddy the waters further

all this talk is just about static balance - ie both blades weigh
the same.

what about dynamic balance ?  say pitch
of one blade is greater than the other ?

Guys,

Do the props need balancing? i mean since they rotate at such high speeds, a slight difference in weight distribution could create a whole lot of vibration isn't is?

How does one deal with this situation?

Pankaj

this one is a good thread on prop balancing
http://www.rcindia.org/tools-materials-and-building-techniques/building-tip-balancing-propellors/

I was just browsing around some days back and got a prop. chart , this might help anyone decide a prop to buy according to the engine size..

hope this helps ?

cheers

atul g.

Most props come fairly well balance now a days.
I have never felt the need to do any special balancing for electrics.

Sai

Saikat

Is it not a fact that one gets better performance of the plane (better thrust and better control) when the prop is balanced, be it an IC engine or an electric motor ?

We have seen it a number of times at Kovalam. I think Sai can bear witness to this fact as he has changed props to get better performance in actual flight...

So, prop balancers are not I think running in cahoots with prop manufacturers.

Another fact is that any imbalance in pitch (dynamic imbalance) will also be seen with the wobbling of the aircraft and excessive vibrations. An imbalance on the shaft of the motor or IC engine can spell disaster for its life as the rpm will be high. Also the vibrations when transferred to the model will spell disaster for its structure

Saju

Isn't balancing props critical for larger engines (like, say a 50cc gasser) ? 

And how does one balance the spinner ?