hurk1

Balancing is a good idea period! Two people had it right , any good mechanic balances a rotating device and you wouldn't drive around without balancing your tires in your car. You don't have to get crazy with the balancing but vibration kills. I balance my stuff but I still have a veco 19 and pico 61. Still run well. Plus I don't have the money to replace stuff like some people do.

mikekosatka

My Feedback: (7)

One further comment. A smaller diameter prop is much less critical than a larger one. I balance my props while I build and usually do a few extras, but 9, 10, 11, 12s it's not a big deal. My planes with 16 inch on up need balancing or they WILL affect the plane. As far as car tires... specious arguement. They have a huge diameter and weight and are not applicable to props. When I balance little props, I use superglue on the back side of the prop and hit it w/ fixer. a light sanding usally will make it perfect in less tham a minute total.
Mike

Gray Beard

My Feedback: (-1)

Just think about what that vibration is doing to the poor little engine bearings. [&o] No prop has ever gotten into my flight box without being balanced first.

MinnFlyer

My Feedback: (4)

Sorry I haven't chimed in sooner, but I just got back from vacation.

First I will say that I will not tell you NOT to balance your props.

Second I will say that I do not bother balancing any props under 18"

Third I will say that I have never had to replace bearings with the exception of one time when I had some that were rusty.

So my point is: There are many newbies who are afraid to even think about starting their new engine without first going out and buying a prop balancer - you don't need to.

As to my choice for props - Graupner is my favorite. The reason is simple: I have tried many props, and while I would see a difference between different size/pitch combinations, I never really saw a difference between brands (At least not in the "Under 14" range) until I used a Graupner. There was a noticeable difference between Graupners and any other brand.

They are available here:

http://www.hobby-lobby.com/grprop.htm

As for 2nd favorite? I don't have one.

My favorite prop for a beginner is a Master Airscrew because they work good, they're durable and they're cheap.

golfdaddy720

I see the pros to balancing, but why use the spinning type balancers mentioned. I have a balancer for my lawn mower blades that is like the old time car (real cars, not models) tire balancers where you lay the blade/tire on horizontally and take material off the side that is hanging low. The one I bought for my mower blades (Ace Hardware) has a cone (with graduations on it to center the object being balanced) that rides on a pointed shaft that fits up into the point of the cone. Seems to make sense to me.

Missileman

That should work ok,
My spinning balancer is suspended between 2 magnets and may be slightly more accurate but your method is by far better than nothing and should be good enough.

Warnberg

My Feedback: (1)

I balance every prop I get..... test it yourself.... take a prop, don't balance it, don't even test to see how out of balance it is and put it on the plane... start the engine and throttle up.... feel the plane... now shut it down, take the prop off, balance it and do it again...
Then you decide....

Yes I have seen some props (1 to be exact) that was sufficiently balanced out of the box, the rest? Anywhere from off to WAY off... personally I do not want something that is spinning in the neighborhood of 10,000+ rpm out of balance....

BantamTJ

I'm researching this topic as I'm a firm believer that anything that rotates needs to be balanced due to less wear & tear, less structural stress, & increased rpm. I started balancing or at least checking props while I was only running two strokes & APC's were a good choice that seldom needed any adjustment, since then I've ventured off into 4 strokes, grabbed the correct prop for engine break-in, and I had so much vibration @ say 1/3 throttle & less, I thought the horizontal stab was going to snap. So I'm looking at balancing props alot closer now on these 4 strokes (this being my first). I fashioned a crude balancer from 2 faucet washers (new) beveled ends toward the prop & poked a piece of radio antenna though the washers, I have the radio antenna ends supported on two pieces of angle aluminum (inverted) & the prop swings through, between the rails. After looking at the post above, it looks about like the "finger balancer" mentioned.

Regent

Ok, let me add a little fuel to the fire here. How many of you that balance your props after it has been reamed and balance them in more than one orientation? You can count me firmly in the camp that balances their props and I go one step further. After the prop is balanced so that it hangs level I then rotate it 180 deg. and see if it still is in balance. Sometimes it will try to rotate back to the previous orientation on it’s own. If it does this I then drop it in the trash. I have tried to correct this out of balance problem by drilling holes in the hub and using CA and filling with solder but I eventually quit this practice. The cause of this kind of out of balance condition is most often caused by the hole not being reamed correctly.

What I would really like to do is to find a way to accurately orientate the prop relative to the crank so as to aid in balancing the engine similar to the harmonic balancer on the old Chevy 454. Does anyone have any ideas on how to do this?