prop balance

DEWATSON · #1 03-12-2012, 01:08 PM

Fellow RVers,

I had my good friend Brian Wallis pay me a visit last Thursday to balance the propeller on my RV8. I had no idea how much difference this would make. My propeller was installed brand new from Vans (Hartzell) and I have flown it as installed for about 192 hours. During the 192 hours I have been fine tuning and correcting the things that were just out of reach or needed to be improved. I finally got to the propeller. Brian spent about an hour and a half with his high tech DYNAVIBE prop balancer and made the airplane as smooth as glass. The fee was $250.00 and it was well worth the money. If you haven't spent the money to have your propeller balanced, you might ought to think about it. IMHO it is well worth it.

Call Brian Wallis...he is mobile and can come to you.....404-405-1315.

David Watson
49FD

Bob Axsom · #2 03-12-2012, 02:08 PM

I guess it's OK if you always operate at the balance speed. I don't and I'm not happy that I did it. Done by Hartzell at Piqua, OH.

Bob Axsom

Walt · #3 03-12-2012, 04:21 PM

Bob,
If you're ever in the neighborhood I'd love to do yours. We could do a before and after at a few different speeds and look at the difference. I know Hartzell did yours and never did a final check, perhaps they messed up the final weight installation, I know you've not been happy since

Bruce · #4 03-12-2012, 06:02 PM

Bob,
Walt did mine and it is great.
Let him look at it at one of the races in the area.

I had a plenum but he needs to get to the first bolt on the
top of the case.
If you have a plenum then he will have to work something out.

See ya March 31.

brianwallis · #5 03-12-2012, 07:07 PM

Thank you sir! I always appreciate a good review! One of these days when I'm rich and famous I'd love to do all this for free..... however kids get expensive....... real expensive..... I'm sure nobody else knows this ... grin....
Bob, if you are not happy with your prop balance, you should take it back to them. I would personally give them a chance to fix it before I told 15,000 people that you are not happy with their work. We are all human and we all make mistakes. If they did their job right and the blades are also in track, the vibration should not change much with change in RPM. If you don't want to go to them, let Walt take a look at it. It could also be related to the propeller installation. I am also available for consultation if you need

Best
Brian

Bob Axsom · #6 03-12-2012, 09:52 PM

Sorry folks I'm racer not a pacifier. I went there, flew several hundred miles paid for a motel, spent two days to have the job done by the manufacturer. I fail to see the magic but there are thousands out there like me that will give it a chance. I hope you are all happy together but don't expect me to say it is a good thing or be quiet when my experience does not support it. Dynamic balancing is done at one RPM and if you operate 300 RPM away from it - well it is dynamic isn't it.

Bob Axsom

DEWATSON · #7 03-13-2012, 06:42 AM

Bob,

I did not mean to strike a nerve with my post. I'm sorry that you aren't happy with the results of your prop balance. I think I would tell the manufacturer and see if they offer to correct the problem.

My airplane vibrated quite a bit at every RPM above 2000. When Brian finished the work, the airplane was much smoother at every RPM and glass smooth between 2350 and about 2650 RPM. The work greatly improved the smoothness of my airplane and I feel that it was well worth the money. I'm very happy. I'm sorry that you had a bad experience.

I also understand that you often run your engine full tilt; I hardly ever do this. I don't know if it is practical to balance your propeller at WOT, but it seems you would be happier if it could be done. Good luck and be happy.

Walt · #8 03-13-2012, 07:12 AM

We can balance at WOT if you can keep it on the ground long enough to get a reading

Bob Axsom · #9 03-13-2012, 07:27 AM

Sounds like you had a problem that needed fixing and you got it done. That is good for everyone and demonstrates that it is a good process. I had no problem except the need for maximum speed. Even though I was told it would only smooth out operations and not give me any speed improvement I went after it anyway thinking if I eliminate some vibration in the propulsion system I should get more power and speed. I got nothing that I can determine by my senses. Maybe it is smoother at 2400 rpm but I never run it there so I don't know and it doesn't make any difference to me if it is. My caution probably falls into the "if it ain't broke don't fix it category." I'm glad it worked out for you and others.

Bob Axsom

lrfrey · #10 03-13-2012, 08:05 AM

I have noticed vibration in my engine and am assuming it is, in large part at least, in need of prop balancing which I intend to have done shortly.

I am running a TMX-IO360 with the standard Sensenich FP Prop. In thinking about it, when you install this combination you have to file away a corner of the large washers that would otherwise interfere with the spinnner flange. Obviously, if they are not trimmed to the exact same weight there will be some imbalance.

Before I get this setup balanced I intend to remove the washers and insure they all weigh the same with a gram scale. Has anyone else found this useful or found smaller washers washers with the proper bolt hole size?

Larry