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  #41  
Old 11-29-2019, 09:17 AM
flysrv10 flysrv10 is offline
 
Join Date: Jan 2010
Location: Florida
Posts: 295
Default

Quote:
Originally Posted by majuro15 View Post
I'm having issue with airframe vibration on my newly flying 10 with an Aero Sport 540 and the 375HRT WW prop. I dynamically balanced it from .6 down to .04 but still feel the vibrations while flying at all RPMs. Seems reclocking is another trick to try, as a few folks have recommended it. I don't have to move bushing or anything, but how do folks determine how much to reclock? For reference, I had to add 60 grams to balance the prop. When the engine stops, the same blade is always at 6 oclock, putting the weights at 12 oclock. Should I reclock it by a certain rotation? 45* or 90*?
I rechecked men one bushing clockwise as others had indicated on this subject. You will have to move the index bushing. Don't overthink this.
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  #42  
Old 11-29-2019, 10:27 AM
lr172 lr172 is offline
 
Join Date: Oct 2013
Location: Schaumburg, IL
Posts: 5,768
Default

Quote:
Originally Posted by majuro15 View Post
I'm having issue with airframe vibration on my newly flying 10 with an Aero Sport 540 and the 375HRT WW prop. I dynamically balanced it from .6 down to .04 but still feel the vibrations while flying at all RPMs. Seems reclocking is another trick to try, as a few folks have recommended it. I don't have to move bushing or anything, but how do folks determine how much to reclock? For reference, I had to add 60 grams to balance the prop. When the engine stops, the same blade is always at 6 oclock, putting the weights at 12 oclock. Should I reclock it by a certain rotation? 45* or 90*?
You follow the hartzell recommendation. I can send you the hartzell doc that tells you where/how to reposition the lugs. Send me an email request and I will reply with the doc. I did mine during the engine overhaul.

EDIT: sorry, just realized you don't have a hartzell. However, the same clocking approach would probably work. I would be a bit concerned though as yours is a much lighter prop and may not respond the same way. I have not read of anyone doing this with a WW, so be carefull in following this recommendation.

Larry
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N11LR - RV-10, Flying as of 12/2019

Last edited by lr172 : 11-29-2019 at 10:32 AM.
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  #43  
Old 11-29-2019, 12:55 PM
Larry DeCamp's Avatar
Larry DeCamp Larry DeCamp is offline
 
Join Date: Apr 2010
Location: Clinton, Indiana
Posts: 1,051
Default Another thing to be aware of.

A 2 1/4 extension is solid , not a spool. This requires the prop bolt holes to be 30* off from the crank flange holes. Unless the prop is correctly drilled to be compatible with this, you CANNOT align the prop horizontal (colinear) with the crank journal at TDC. My 0320 is totally balanced on engine parts and prop dynamically balanced. It is way better than a Cessna, but not turbine smooth.
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Larry DeCamp
RV-3B flying w/7:1 0320 / carb / Pmags / Catto 3b / digital steam
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  #44  
Old 11-29-2019, 02:12 PM
Dustyone Dustyone is offline
 
Join Date: Oct 2012
Location: Brisbane,Austalia
Posts: 193
Default Hartzell not balanced from new

Hi Tim and others with prop vibration,

For over 4 years I lived with a vibration that I came to accept as normal in my RV-10. I had the prop Dynamically balanced 3 times and tried to convince myself it was somehow a little better.

It was not until a persistent front crank seal oil leak convinced me to remove the prop and take it to Suncoast Aero Engines Prop shop here in Australia to have a look at it while I was replacing the crank seal.



I visited the shop while the work was been done and was surprised that my prop was over 40 grams out of static balance and the technician was as surprised as I was ! He commented that it was rare to find a hub that was so far out of balance. It required weights to be added on both axis to get it right.






So going back on the aircraft I also re-clocked as per the instructions listed here and have finally be rewarded will the smoothest ride I have had in my '10.
The highly accurate vibration analyser I have in my aircraft ( sunvisors )are now dead still in cruise instead of the continual flutter I had been used to.
I also Dynamically balanced the prop and engine combo again and it balanced easily.

Very disappointed to find out that it was my new "balanced" Hartzell that was the problem all along but very happy to close this chapter on my RV-10 and call it DONE !
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RV-10 #40597
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Last edited by Dustyone : 11-30-2019 at 01:58 PM.
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  #45  
Old 12-03-2019, 09:46 PM
ReidVaitor ReidVaitor is offline
 
Join Date: Jun 2006
Location: SoCal
Posts: 179
Default Hartzell our of balance

I just went through this as well. Your photos look exactly like my case. For years I flew with a vibration, it was there from first start on. I had it balanced and was told it was almost perfect... still had a vibration. Finally, like you, we had the prop balanced and required a serious amount of weight to get it right . the plane is so much more smooth now.
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  #46  
Old 12-03-2019, 11:43 PM
erich weaver's Avatar
erich weaver erich weaver is offline
 
Join Date: Aug 2006
Location: santa barbara, CA
Posts: 1,707
Default

The previous few posts seem to indicate that somehow a static imbalance was not being detected during dynamic balancing. That doesn?t make any sense to me; I?ve always been led to believe that a dynamic balance replaces and is superior to a static balance. Anybody care to correct this and explain?

Regards
Erich
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  #47  
Old 12-04-2019, 09:38 AM
D Weisgerber's Avatar
D Weisgerber D Weisgerber is offline
 
Join Date: Sep 2019
Location: Ionia Michigan
Posts: 213
Default

So after the static balance do you dynamically balance it? I would think you would have to to make up for imbalance in the spinner and backplates.
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Working on the finish kit.
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  #48  
Old 12-04-2019, 05:59 PM
Dustyone Dustyone is offline
 
Join Date: Oct 2012
Location: Brisbane,Austalia
Posts: 193
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Hello Erich,

I was also confused as to why the dynamic balance only made minor changes to my vibration .
My thoughts are that the weights were added in both fore/aft hub location and blade location so maybe if I had access to a better prop balancer like the Dyno Vibe pro, I would seen the half order vibration recorded.

(My prop was balanced with backing plates and spinner fitted)

This is an extract from my report,

Suncoast Aero-Props
?Also for your information, Your blades are tracking exceptionally well (1/64?) and the blade angles were spot-on with 13.5? for the low pitch and 30.7? for the high with no variation between the two blades, so there?s no issues there.
The balance weights I added equate to about 50grams of weight, so hopefully after re-clocking the prop 180 and another dynamic balance your vibration should be remedied?.

I would definitely be checking static balance if you have already done a Dynamic balance with no improvement.
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Ashley Miller
RV-10 #40597
Dual SDS CPI
http://www.vansairforce.com/communit...d.php?t=140051
Airflow Systems Air-Con
http://www.vansairforce.com/communit...4&postcount=15
VH-XTE 700hrs +
Redcliffe,Brisbane
Australia
Photos : https://goo.gl/photos/zsfBeVofHMe4ze7i7
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  #49  
Old 12-04-2019, 07:27 PM
ReidVaitor ReidVaitor is offline
 
Join Date: Jun 2006
Location: SoCal
Posts: 179
Default Why static not being picked up in dynamic

My guess, last person to do mine knew what he was doing (30 years in dynamic balancing of helo blades) and possibly the one prior to that didn?t. I don?t think it was any more than that. It wasn?t statically balanced after I added a spinner and other parts Hartzell didn?t include initially; it was dynamically not corrected and I thought it was, based on feedback, now it?s done correctly and it?s right.
You are correct dynamically it should pickup an unbalanced static.
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  #50  
Old 12-04-2019, 08:26 PM
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Walt Walt is offline
 
Join Date: Aug 2005
Location: Dallas/Ft Worth, TX
Posts: 5,840
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Quote:
Originally Posted by ReidVaitor View Post
My guess, last person to do mine knew what he was doing (30 years in dynamic balancing of helo blades) and possibly the one prior to that didn’t. I don’t think it was any more than that. It wasn’t statically balanced after I added a spinner and other parts Hartzell didn’t include initially; it was dynamically not corrected and I thought it was, based on feedback, now it’s done correctly and it’s right.
You are correct dynamically it should pickup an unbalanced static.
To add to the above I think the equipment used to balance may have something to do with it as well. In my experience with tools, test equipment (and most things in life), you get what you pay for. The vib sensor alone that I use with my MVib II balancer cost more than some entire vib kits. I've also seen folks post balance results that I know are practically impossible to obtain. In 15 yrs of balancing hundreds of airplanes I've never been able to achieve 0 IPS.
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EXP Aircraft Services LLC
Specializing in RV Condition Inspections, Maintenance, Avionics Upgrades
Dynamic Prop Balancing, Pitot-Static Altmeter/Transponder Certification
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RV7A built 2004, 1700+ hrs, New Titan IO-370, Bendix Mags
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Last edited by Walt : 12-04-2019 at 08:32 PM.
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