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General control line discussion => Open Forum => Topic started by: Michael Massey on December 18, 2011, 05:11:55 PM

Title: Yes! I Balance My Props
Post by: Michael Massey on December 18, 2011, 05:11:55 PM
So I took out my brand new Pro Zinger 12x5 and decided to cut it to 11.5x5.  I cut off approximately 1/4 inch off of each tapered tip and put it in the balancer.

One tip "rocketed" to the bottom side managing only a couple of small swings after getting there.  So, I cut a little more off the obviously heavy blade. 

I very soon became very clear that balancing this prop was not going to happen.  But I pushed forward just to see how bad the original balance truly was.  Here are the pictures.  Judge for yourself.
Title: Re: Yes! I Balance My Props
Post by: Howard Rush on December 18, 2011, 05:18:08 PM
Sanding the varnish off the heavy blade is usually more effective than whacking the tip.
Title: Re: Yes! I Balance My Props
Post by: Bill Little on December 18, 2011, 05:19:53 PM
I wonder just how thin it would have ended up with the sanding done. ???  Maybe a combo of sanding and adding extra coats of varnish to the light blade........

BIG Bear
Title: Re: Yes! I Balance My Props
Post by: proparc on December 18, 2011, 07:00:09 PM
I thought I was the only one who "pushed forward" when I had a turkey prop, to see what would it take to balance it.  As you probably know, if you attempt to actually fly it, you will get a dynamic imbalance from one blade pulling more air than the other, and it will screw you up bad-real BAD!!!   n~
Title: Re: Yes! I Balance My Props
Post by: Paul Taylor on December 18, 2011, 08:40:10 PM
Charlie Reeves does a great job with wooden Props.
He repitches the props and presses small rods into the hubs to keep the hub from crushing.
Title: Re: Yes! I Balance My Props
Post by: Michael Massey on December 19, 2011, 12:01:18 AM
I admit sanding is a better approach.  I generally do that.  But it was very clear, very quick, that no amount of sanding was going to help this "paint stirrer."  I had to grind off nearly 1/2 inch on the heavy blade to get it to balance.  Just had to so I could see just how bad it was.

Bad...bad!
Title: Re: Yes! I Balance My Props
Post by: Brett Buck on December 19, 2011, 12:12:42 AM
I thought I was the only one who "pushed forward" when I had a turkey prop, to see what would it take to balance it.  As you probably know, if you attempt to actually fly it, you will get a dynamic imbalance from one blade pulling more air than the other, and it will screw you up bad-real BAD!!!   n~

     I don't know, there have been a fair number of airplanes flown with single-bladed props, and they didn't shake themselves apart. This is likely to be a lot better balanced than that.

   Brett
Title: Re: Yes! I Balance My Props
Post by: proparc on December 19, 2011, 12:19:54 AM
     I don't know, there have been a fair number of airplanes flown with single-bladed props, and they didn't shake themselves apart. This is likely to be a lot better balanced than that.

   Brett

I didn't mean structural failure. But if, you mean those speed jobs that turn a zillion rpm your right. But I haven't notice them doing to much maneuvering. Although, I have to remind myself that in stunt, just about anything can be made to work,(Milton remember the Humbug-remember the Humbug).
Title: Re: Yes! I Balance My Props
Post by: john e. holliday on December 19, 2011, 08:47:52 AM
I was told long ago to check blade length on any prop before even trying to balance.   The old Tornado pressed wood props were the best coming out of the box to the plane and fly.   The nylons were close after sanding leading and trailing edges.   APC's are close also after sanding LE/TE.   Yes I have had some wooden props from Top Flite, Master Airscrew and Zinger that needed work.  Most of how to balance has been stated.   

By the way F2C uses single blade props.   H^^
Title: Re: Yes! I Balance My Props
Post by: Brian Massey on December 19, 2011, 11:25:38 AM
I've found that Xoar wood props are very close to their rated specs right out of the package. The most I've "trimmed" to get them to balance is light sanding. Pitch is usually very close too.

Brian
Title: Re: Yes! I Balance My Props
Post by: George on December 19, 2011, 06:21:11 PM
The first thing I check on an unbalanced prop is that the hole is drilled correctly.

George