What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Balance Master?

Sounds similliar to the Landoll harmonic balancer I used on my -6. Worked very well with my lightweight Prince prop. Unfortunately Mark Landoll has not sold these for some time now.
 
Yes I have it on my RV12,worked really well, used a dynavibe before and after and it got to .004 IPS, much better in flight now too.
 
Yes I have it on my RV12,worked really well, used a dynavibe before and after and it got to .004 IPS, much better in flight now too.

Did you balance it with the Dynavibe before, or just check it before? What was your ips just before you added the Balance Master?
 
There was a museum in Philadelphia that had an exhibit showing how this could work back in the 1950s. It had a plexiglass disc with three steel balls that were free to spin around the inside, kind of like a roulette wheel. You pulled a lever to lock the balls in place. Pushed a button to spin the wheel which vibrated a lot. Then you could release the balls and like magic they moved automatically to balance the wheel. The disk rotated smooth as glass after the balls moved to a balanced position.I saw this as a child and never forgot it. Suspect the Landoll balancer works on the same principle.
 
Found this Youtube video with a before/after dynavibe reading on a Rotax 912 (not a RV-12 though).

https://www.youtube.com/watch?v=iZ8GqUNUcbM

Pretty impressive results I think? From .37 to .05 ips @5000 rpm before/after balance master install. And from .36 to .04ips at 4000 rpm before/after. .36 to .13 at 3000rpm
 
The method of a free moving mass to balance a rotating object has been used in many ways. I have heard of sand or steel BB's used in tubeless tires, the only issue was if moisture got inside the sand would clump and not move freely.

here is a product doing that;
http://www.innovativebalancing.com/index.php

From the video with the Dynavibe it appears to not hold balance when the RPM changes there is a lag for the balance to settle in.

I still think fixed weight is the best.
 
1+ works well

I have been running this on an O-320 w/ CS prop for 4+ years, very satisfied. I have also been through a 10yr OH on the prop, and as long as it is within reasonable rotational balance then the device takes care of the rest.

I mention rotational balance specifically as the device is a disk with a tube and maybe 1/2 oz of mercury to spread out and provide rotational balance. The nice thing is that it will balance over a wide range of RPM which fixed weights obviously cannot.

This is NOT A LINDOL device which is for torsional dampening of power pulses and crankshaft spring and provides a dampening though a mass and viscous fluid.
 
The nice thing is that it will balance over a wide range of RPM which fixed weights obviously cannot.

You are accurate sorta. Fixed weights applied on a static balance typically only balance at one RPM.

Dynamic balance will balance at all RPM's.

If you question this consider your car tires that are dynamically balanced, they run balanced at all speeds. In the OLD days when the norm was a bubble balance (static), you would get a wheel shimmy at certain speeds.
 
Did you balance it with the Dynavibe before, or just check it before? What was your ips just before you added the Balance Master?
Yes I did it before and after.
Before I was at .12 to .16 depending on RPM checks.
proof to me was flying it after i installed it, was smoother at all rpm's, you could just feel it right away.
 
My hangar mate has a Rotax powered Kit Fox with a three bladed prop and he tried the Balance Master device. He has prop balancing equipment and has helped me balance the prop on my RV12 and several other planes.

He didn’t find the Balance Master helped his Kit Fox running it on an already balanced prop. He offered it to me and I was interested but wasn’t sure how I would install it with my Sensenich so I’m interested in seeing how others did the install.
 
You are accurate sorta. Fixed weights applied on a static balance typically only balance at one RPM.

Dynamic balance will balance at all RPM's.

If you question this consider your car tires that are dynamically balanced, they run balanced at all speeds. In the OLD days when the norm was a bubble balance (static), you would get a wheel shimmy at certain speeds.

Not an apples to apples comparison.....

A vehicle wheel/tire assembly doesn't have a variable vibration influence to the degree that an airplane engine / propeller combination does.

If what you say was true, we would just do a dynamic propeller balance at idle speed and get a good result for the entire RPM range but that doesn't work. In fact, the makers of the balancing systems recommend doing the balancing process with the engine operating at cruise power and RPM to get the best result.

With a fixed pitch propeller like on the RV-12 we can't do that so we get as close as we can by using full throttle and accepting what ever the static RPM is.
 
Not an apples to apples comparison.....

A vehicle wheel/tire assembly doesn't have a variable vibration influence to the degree that an airplane engine / propeller combination does.

What is a “variable vibration influence”?

If you are referring to engine vibrations influencing the reading the gear reduction puts the engine vibrations at another frequency than the one used in the balance readings.
 
What is a “variable vibration influence”?

If you are referring to engine vibrations influencing the reading the gear reduction puts the engine vibrations at another frequency than the one used in the balance readings.

Power pulses produced by an engine have an influence on the vibration loads that are induced into the engine / propeller system.

Power pulses vary depending on the actual power being produced by the engine (idle vs max rated power).

That is why some engine propeller combinations on some engines have restricted operation ranges.
 
In the case of a lycoming (direct drive) you are correct. The power pulses are always timed with the prop so they become part of the equation during dynamic balancing. In the Rotax because of the gearbox and the ratio being 2.53:1 the engine pulses are constantly changing in relation to the prop. Additionally the engine pulses are at a much higher frequency and easier for the balancer to filter out of the equation. You will feel different vibration levels at different RPM’s but they are not coming from the prop (assuming it was balanced).
 
Back
Top