Propeller / aircraft vibration

[mike_elliott]

It's a function of Amplitude. There have been vibration studies done on the Cessna 188 when converting from a 2 Blade C98 McCauley propeller to a 3 blade propeller of any Flavor, the vibration would get worse... I have been told that a certain type of lord mount, made from a different compound which was more rigged was the fix in that application.

Not sure if test like that have been done with M20's or not.

I work on Propellers an Balance then for a livin an I can tell you from personal experience the 2 blade propellers are smoother.

I fly a M20F with a C3YR/F7282 propeller balanced to less than .03 ips

On the field here is a M20G with a C2YK/F7666A-2 propeller that his balanced down to around .05 ips if my memory is correct.

The G model is smoother than the F even though the Chadwick balancer says otherwise.

I'm not sure if it's the extra weight out front allowing the mounts to flex a little more like in the case of the cessna 188 or not...

But it's puzzling to say the least . My 2 cents.

 

I have found the same to be true on my F. I sent my old 2 blade to Hartzell back in 2004 to be OH'd. They declared it dead and offered to sell me a new 3 blade for "cheap". I tried it and they tried to balance it (where they said it was near perfect balance - forgot the ips numbers now), the vibration was considerably more than the old 2 blade, which wasn't balanced. THe cruise speed was reduced about 3-5 kts, but climb was better. After numerous attempts to satisfy me, Hartzell was given an order for a new 2 blade. I ordered it thru Lasar, as they were 2K cheaper than thru hartzell direct for the same prop.

Of course, within a year, they came out with the infamous Hub AD and special "deal" for a new 2 blade scimitar they had under wraps for about 4 k less than I just paid for the 2 blade. But at least I have a no ad hub, and a silky smooth prop/engine combo that isn't penalized with speed, nor restricted to below 2500 at high MP's like the new ones are.

[Cody Stallings]

Hondo

It's tough to say which one is better, both do the same thing, an both are very capable units.

I personally am a fan of the Chadwick's. We have 4 of them here, an all are great machines. I have found myself in the field verifying what a 2020HD was doing with a Chadwick a time or two. But I don't belive it was anything to do with the balancer, more so the operator.... You will be happy with the results from either unit.

[KSMooniac]

Cody, any chance you'd travel a little bit to do prop balances?  Maybe if you could line up a few to knock-out in one day at one location?

[Cody Stallings]

There is a very good chance of me traveling to do a Balance. I do a lot off it.

I really enjoy going out in the field an meeting the people on this site face to face, while fine tuning an already fine tuned rig.

[chrisk]

There is a very good chance of me traveling to do a Balance. I do a lot off it.

I really enjoy going out in the field an meeting the people on this site face to face, while fine tuning an already fine tuned rig.

 

Let me know when you are coming to Texas!

[Cody Stallings]

Chris, I was in Vernon Texas on Tue delivering a Round engine prop. I will give you a shout Next time I'm in texas an we will get your prop handled