D

DEWATSON

Well Known Member
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
 
I guess it's OK if you always operate at the balance speed

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
 
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 :confused:
 
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.
 
Thanks!!!

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
 
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Sorry folks I'm racer not a pacifier

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
 
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Bob

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.
 
We can balance at WOT if you can keep it on the ground long enough to get a reading :D
 
Now if I had a problem like that I would do it too

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
 
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
 
I just had my prop balanced

Here are my comments. I have been flying our RV6A for 3 years now and decided to have the prop balanced at this annual just because-----. The initial vibration factor was .38 as read by the unit Boomerang Aviation uses for balancing. This was with a static RPM of 2000. I was told that anything under .5 is acceptable but my friend Tomo said he could get it better. We put weights on the flywheel as recommended by the machine and we were able to get the vibration down to .1, again at 2000 RPM. On the ground I saw no difference but let me tell you, in the air there is no comparison. The difference through the entire cruise range from 3000 to 4800 RPM was so significant that my partner and AP said he thought the engine had stopped developing some power. I am very pleased with the results and can only conclude that if there is some malady after a balancing procedure, a mistake must have been made in the weight placement or amount. Blue skies.
Woodman
 
Not sure where some of those number came from but here is the industry standard numbers for vibration levels (more info on our website if you're interested, we guarantee .07 or below but normally get it down to .04 IPS or less):

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DANGER ? 1.25 Inches Per Second (IPS) Peak Amplitude. The propeller should be removed and a static balance performed.

VERY ROUGH ? 1.00 Inches Per Second (IPS) Peak Amplitude. Propeller can be dynamically balanced; however a large amount of weight will be required. A propeller static balance is recommended. Operation at this vibration level could cause damage.

ROUGH --- 0.50 Inches Per Second (IPS) Peak Amplitude. Propeller definitely requires dynamic balance. Long term operation at this vibration level could cause excessive wear.

SLIGHTLY ROUGH -- 0.25 Inches Per Second (IPS) Peak Amplitude. Dynamic balance will improve passenger comfort.

FAIR---- 0.15 Inches Per Second (IPS) Peak Amplitude. This is the maximum acceptable vibration level after dynamic balancing.

GOOD ---- 0.07 Inches Per Second (IPS) Peak Amplitude. Vibration levels below 0.07 will not be detectable by pilots or passengers.
 
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