Dynamic Prop Balance

[Jsavage3]

I was told recently, by an A&P who flew my Mooney, that I would be very pleased with the results if I were to have my Mooney's prop dynamically balanced.  I knew that my mag compass always shook alot, but I had always just picked an RPM that seemed to minimize the vibration.

 

Well, I had my prop dynamically balanced and the results are very impressive.  I could feel and see a difference as soon as he added the first weights.  After 5 or 6 "vibration" runs, he had it down to 0.1 ips where it had previously been at 1.2 ips...intervals per second, I think is what he was calling IPS.  

 

Bottomline, this is a drastic improvement -- my comfort, will save my avionics, engine mount, airframe, etc and now I can actually read the heading from my mag compass!  It cost me $375 and I feel this was some of the best money I've spent in a long time!

 

If your bird hasn't been balanced, I'd like to put in a good word for having this done -- I trust you will be pleased with the results.

 

Keep those Mooney's flying fast!

[Marauder]

How am I going to get my martinis shaken now? Are you telling me that I will need to get accustomed to stirred martinis?

Not sent from my underpriced Nexus 7 using Tapatalk

[orionflt]

No Chris, just the cyclic motion on the flight controls while jamming to xm radio will do the trick.

[The-sky-captain]

Good pirep! I've got my annual coming up next month and emailed Maxwell just yesterday inquiring about a dynamic balance.

[HopePilot]

The least expensive, high-value improvement I ever did.  The difference afterwards was substantial (in terms of smoothness) and I guess I picked up half a horsepower in added efficiency.

[kmyfm20s]

What is considered acceptable as a finish number?  I had mine balanced and I think it was .3 from 1.1 after 3 runs. While it did improve the vibration it wasn't as great as I thought it was going to be. It seem like it was optomized for 2200 RPM and I usually run 2500 RPM where it is unfortunatley the ruffest in the my RPM range. I would still do it again and it is better but I was expecting less vibration.

[MB65E]

Some of these guys can tell you exactly where the vibration is coming from. Weather it be from the prop, crankshaft, accessory case, or cylinders. At 1.2 ips, .1 is a drastic improvment! Can't imagin how that felt. Most aircraft can be balanced down to .05 ips. Super nice at .02 ips! .05 is a good target!! Most runs can be done in 3-5 starts. Highly recommend as well!

-Matt.

[Mooneymite]

Dynamic balancing is good!  However, make sure they guy who does it knows how/where to place the balancing weights.

 

If placed on the spinner back, they can cause cracking, or worst cast scenario, a loss of spinner.  That smooth running prop won't seem so smooth!

 

Any A&P can buy a balancing box and go into business.....

[kmyfm20s]

Where should they place the weights?

[MB65E]

Only on the prop! Hartzells have a spot on the hub for the screws and special plates. McCauley I'm not sure about. The back of the spinner is not a good place. It's off the arc of the disc of the propeller. As close to the disc as possible. It works, some guys do it. However, it's only really only being lazy as they need to remove and reinstall the spinner each time when the weights are on the hub.

-Matt

[Cody Stallings]

Dynamic propeller balance is a must for the rough running 4 cyld engine. The Repairstation I work for provides this service. You see many happy customers after you balance their propellers.

Well worth it. My 2 cents.

[yvesg]

Can someone post pictures of the weights on an hartzell prop? I got mine balanced a year or two ago and have not seen any weights anywhere. I will definitely ask my mechanic how he puts the weights on.

Yves

[Seth]

I plan to have my prop dynamically balanced right after the annual. 

 

For those in the mid-atlantic, where is the offered?  I had heard LNS has a good shop that does it, correct?  Where else within 200 miles of the DC area?

 

-Seth

[ALP]

Dynamic balance is the way to go. Took mine from .75 ips to .03 ips @ 2500 rpm. Huge difference. After test flight I found 2500 rpm smooth as glass but a little rough around 2000/2100. I was told they like to balance to the rpm your going to fly at.

 

Seth, there is an IA from Binghamton NY area that comes to your airport. I believe he comes down to MD. He will also supply a 337 to go with if required.  IIRC it was about $325 if you can line up several planes for his trip.

 

Al

[orionflt]

Can someone post pictures of the weights on an hartzell prop? I got mine balanced a year or two ago and have not seen any weights anywhere. I will definitely ask my mechanic how he puts the weights on.

Yves

Normally if installed properly on the lycomings you won't see it because it is just longer bolts and extra or thicker washer installed holding the spinner back plate to the flywheel. I got lucky when I put my plane back together last year, I did the dynamic balance and found that it was already at .03 ips just from the static balance. I wasn't looking forward two taking the spinner on and off multiple times tweaking the weight.

[Danb]

There is a prop shop next to Webers Msc's at lns. Maybe Weber also dose them?

[Marauder]

There is a prop shop next to Webers Msc's at lns. Maybe Weber also dose them?

I think they are called East Coast Propeller Service in Lititz, PA. They have done the last 2 overhauls for me.

Not sent from my underpriced Nexus 7 using Tapatalk

[bnicolette]

The one at Lancaster is Sensenich Propeller Service:  $265 

 

priscillasps@aol.com

 

800-462-3412

[N601RX]

I had aircraft specialties dynamically balance all my internal engine parts before we reassembled it. The stock crank crank was out by 10 grams. It is very smooth now. If the out of balance is due to rear throws on the crank adding balance weights around the spinner will not completely get it in balance.

[OR75]

Dynamic balance is the way to go. Took mine from .75 ips to .03 ips @ 2500 rpm. Huge difference. After test flight I found 2500 rpm smooth as glass but a little rough around 2000/2100. I was told they like to balance to the rpm your going to fly at.

 

Seth, there is an IA from Binghamton NY area that comes to your airport. I believe he comes down to MD. He will also supply a 337 to go with if required.  IIRC it was about $325 if you can line up several planes for his trip.

 

Al

 

 

I had my prop dynamically balanced recently

 

Much smoother at start up and very smooth during climb. However, when I throttle back vibrations increase andthey are highest in the 2200-2400 range. Right where I like to operate

 

Anyone seen that ? I was operating the engine during the balancing and test was done at 2300

[Shadrach]

Sensenich is on the field at LNS, but I believe East Coast Propeller will drive out to the field and do it by appt. Mine is at .55 inches per second, the last guy to mess with it did not feel comfortable mounting the weights on the spinner so it's on my list of things to do. 

[Jsavage3]

I had my prop balance done at Aircraft Specialists at KJVY, which is about 10 nm north of Louisville, KY.  The cost was $375.  It's an outside job, so plan accordingly.

 

I have a McCauley prop and they mounted the weights to the inside of the spinner mounting assembly (this assembly stays put when the spinner is removed).  You cannot see the weights once the spinner is removed.  All you can see are the rounded screw heads on the outside and they are located about where the cowling closes down around the shaft between the engine and the prop.  

 

Yes, we ran my Mooney 5 or 6 times and each time the spinner had to be removed in order to add or remove weights (washers).  They told me that 0.2 ips or less was a good goal.

 

The whole process took about 3 hours and I did all of the engine runs myself.  They had me run it at 2200 RPM as well.

 

Yes, the improvement felt & seen when going from 1.2 ips to 0.1 ips is drastic!  $$$ well spent!!!

[fantom]

The prop usually slips away from that dynamic balance over time. Would be good t repeat every two or three years.

[N601RX]

I've been considering buying one for a while.  How much mooneyspace interest would there be in renting one for you and your friendly A&P to balance your prop?  Not really doing it to make money, just to offset the purchase price and cover upkeep and calibration.  Would there be much interest for say 50 or $75 for a weeks usage?

[chrisk]

I'm considering getting a dynamic prop balance (after my recent prop re-seal).  Has anyone had experience with Blue Skies Aviation in San Marcos?  They quote a price of $275 on their website and are 30 minutes from me.  And if you have had a great experience at another shop in central TX, please let me know.