Dynamic In-flight Prop balancer - interesting product

barnstorm2

Platinum Member
Joined
Nov 1, 2003
Messages
14,573
Location
Cincinnati, Ohio
Aircraft
2-place Air Command CLT SxS (project), & Twinstarr Autogyro
Total Flight Time
750+hrs and climbing
I found this while looking for a way to balance my prop...


http://www.balancemasters.com/ultralights/index.html

Balance Masters®
A Must For Ultralight Safety and Comfort

Balance Masters® are PATENTED, DESIGNED, MANUFACTURED AND DISTRIBUTED IN THE U.S.A. and are easy-to-install devices for propellers and Rotax engines. These devices cut the vibration factor on ultralight aircrafts by as much as 50 percent when both balancers are installed.

Balance Masters® are weighted with a high density liquid mass (Mercury). The physical principles of centrifugal and gyroscopic forces explain the action of the Balance Masters®. With the Balance Masters installed, the weighted liquid mass (Mercury) in the apparatus shifts during spinning, and adjusts to compensate for imbalances due to such factors as changes in flying conditions or warpage in the propeller, from nicks and rocks during takeoffs and landings. The Propeller Balance Masters® mounts on the propeller shaft or gear box in conjunction with the propeller. It is less than 7 inches in diameter.

The Engine Balance Master is made to fit most Rotax engines and bolts under the Starter Pulley on the Fly Wheel side of the engine. It is less than 5 inches in diameter. Each device weighs about 4 oz. Installation will take about 25-30 minutes using ordinary hand tools for each device.

Balance Master is designed to fit most propeller bolt patterns and Rotax engines from 277FA through 582. We will need to know the manufacturer of your propeller and engine model to determine the right configuration.

Here is what Harry Whiting, Grand Champion Oshkosh 1991 of the Lightplane category has to say:

I installed your Balance Master to the propeller on the 1991 Oshkosh Grand Champion Rans aircraft and could immediately feel a smoother running engine and propeller. It is important to know that this is our third Oshkosh Lindy trophy winning airplane and it is truly state of the art.

Your Balance Master may just be one of the best values out there, and as a Rans dealer I will certainly recommend its use.

.
 
I used them on my old ironhead harley, (One on the crank, one on the clutch) they did
seem to remove much of the high frequency vibes.
 
I have used the balance master for years. I had one on my Rotax 532 and another on my prop. I still use one on my prop and tried to buy one for my greyhead 582 but the ones they sent that was supposed to fit the 582 wouldn't fit. It's supposed to fit between the crank and the balancer but was too small for the balancer to fit down inside it like it's supposed to. If I could get one for my 582 that would work I'd buy it in a minute. They're well worth buying and using, less vibration can't do anything but help the engine and gyro.

I had an incident once that proved to me it works. I landed and when I pulled the throttle to idle the 532 started shaking real bad at 2000 rpm. I usually idled at about 1800 with the balance master. I wondered what happened and when I looked the round ring that holds the mercury was gone. All I had left was the flat metal piece you bolt to the prop. Naturally I started looking at my rotor blades and prop to see if it did any damage when the ring left and luckily it didn't. I called Balance Masters and told them what happened and they sent me a new one and asked me to send them back the piece of metal that was left so they could do an analysis on it. I put the new Balance Master on they sent me and it was back to smooth again. I'm sold on it.
 
Thanks, for the pilot report Richard!
That helps...
 
I must be getting old, I can't see how it works even when looking at the explanation on their website.
Can anybody explain it to me?

Mike G
 
We use these things on Big Rig Semi's...the wear and tear they eliminate is just amazing. We're talking savings in the multi thousand dollar ranges on the front ends...tire wear changes completly from crap to unheard of levels of balance.
We ran them on all 6 points on the Tractor, and some guys I know of had them on the Trailers too.
My recommendation is this: if Ya' got the cash...these are MUST HAVE for your machine...needed or not. They eliminate harmonic vibes even when you can't feel it or are aware of it. The cumulative engine wear savings over time can't be beat. (Can Ya' tell I'm a strong believer..?)

TIM: Thank you for posting the link and sharing this "Heads Up" with us here...this device is really great...I had no idea they were being made for our Sports' engines.

M-M
 
Question?

Question?

Is the one that bolts between the gearbox and prop enough for the rotax 503 or do you also need to install the (internal, I think) one to gain the benefits?
I wouldn't mind trying the external one but not if it doesn't work as a stand alone unit.
Ben S
 
Ben, The prop balancer works great by itself. I thought I had my Tennessee Prop well balanced on my 503 pusher (Challenger II), but found the addition amazing. It really helps with the turbulance off the wing and airframe. It really 'is' dynamic.
Dave B

ps: The engine balancer pretty much works for the engine itself, but combined with the prop balancer makes for a smooth complete package. Tho mine is belt drive, I would imagine it would help with gearbox chatter.
 
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Thanks!

Thanks!

I will put one on and try it.
Ben s
 
I will put one on and try it.
Ben s

Great news Ben, please lets us know what you discover.
It would make a great thread? Remember no pictures, didn't happen?
 
I wonder........

I wonder........

I wonder what would happen if you mounted one on a rotorhead ?

No more 2 per rev shake ?

It will probably result in locating all the bending moment at the point where the balancer mounts instead of spread out along the mast so DON'T try it.

But I think it is a good point for discussion.

Any thoughts anyone ?
 
I wonder what would happen if you mounted one on a rotorhead ?

No more 2 per rev shake ?

It will probably result in locating all the bending moment at the point where the balancer mounts instead of spread out along the mast so DON'T try it.

But I think it is a good point for discussion.

Any thoughts anyone ?

You would probably have to go back to Norm's old Rotary Forum where this was previously discussed. But here it is in a condensed form.

The company was contacted about using their product on a set of rotors. The specs for an average set of rotors was also provided. The company's email back recommended NOT using them on rotors. That it would not work or provide much benefit.

As I recall they did not provide an answer why they thought it would not work.
 
I must be getting old, I can't see how it works even when looking at the explanation on their website.
Can anybody explain it to me?

Mike G

The prop balancer is just a ring with some mercury inside. The centrifugal force of spinning throws the mercury outward, and the viscous mature of the mercury shortly delays its movements, which tends to help correct any out of balance.

The engine balancer has a ring partially full of ball bearings and oil. The balls tend to move around to find a place of balance, while the oil delays movements, and this also helps to absorb some torsional vibration from the speeding up and slowing down between every stroke.

All Rotax engines have a torsional dampener in the bell-housing under the starter ring. This is just a hollowed donut shape with a steel ring inside with a viscus oil. It works by the ring wanting to stay at a constant speed as the donut speeds up and slows down between strokes. As the donut wants to speed up during a power stroke, the oil and ring have enough drag to show it down, then in-between power strokes when the donut is slowing down, the added momentum that the ring picked up tends to drag the donut faster. Between them, they have a more constant speed.
 
Thanks Dennis, but I still don't see it. In the description of how it works on their website, the mercury is all in one place which I would have expected to cause an out of balance. The website also shows what seems to be another mass opposite the mercury. I wonder if the mercury and the other mass weigh the same and therefore don't cause any additional out of balance and the circumferential movement of the mercury helps absorb torsional vibrations as you described for the Rotax torsional damper. If this is the case this device doesn't "balance" the prop as we usually understand it but reduces the torsional vibrations.
Based on the comments above these things seem to work but I'm still not sure how it works.

Mike G
 
>>All Rotax engines have a torsional dampener in the bell-housing under the starter ring.<<

Just a slight correction to this...

Later model Silver Head 582s (and larger engines) on up to current have the Rotax dampener standard. The Balance Master engine balancer won't work with these.

The older water cooled engines can be easily upgraded to the Rotax dampener, or install a Balance Master engine balancer.

The smaller aircooled engines have never had a dampener, until Balance Masters designed their little lightweight engine balancer.

Dave
 
Thanks Tim looks interesting. May look to see if we would be able to fit one on our 503 and Warp.
 
Based on the recent comments it seems almost certain that this thing should be called a torsional damper and not a prop balancer. If it is a torsional damper then it probably wouldn't do anything for a gyro rotor because the rotor isn't being driven by a variable torsional load from something (an engine) fixed to the gyro frame. It shouldn't do anything for the wheels of a trailer or the non driven front wheels of the rig either for the same reasons. However Mike seems to have experience with trucks that disprove this so I'm still confused as to what exactly this thing is doing.

Mike G
 
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