X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 20 May 2011 07:52:55 -0400 Message-ID: X-Original-Return-Path: Received: from imr-db03.mx.aol.com ([205.188.91.97] verified) by logan.com (CommuniGate Pro SMTP 5.4c3j) with ESMTP id 4989217 for lml@lancaironline.net; Thu, 19 May 2011 23:58:40 -0400 Received-SPF: pass receiver=logan.com; client-ip=205.188.91.97; envelope-from=Sky2high@aol.com Received: from imo-ma03.mx.aol.com (imo-ma03.mx.aol.com [64.12.78.138]) by imr-db03.mx.aol.com (8.14.1/8.14.1) with ESMTP id p4K3w0jp008759 for ; Thu, 19 May 2011 23:58:00 -0400 Received: from Sky2high@aol.com by imo-ma03.mx.aol.com (mail_out_v42.9.) id q.eac.142d9b68 (55732) for ; Thu, 19 May 2011 23:57:58 -0400 (EDT) Received: from magic-m19.mail.aol.com (magic-m19.mail.aol.com [172.21.136.208]) by cia-md03.mx.aol.com (v129.10) with ESMTP id MAILCIAMD037-d9b44dd5e6c537e; Thu, 19 May 2011 23:57:57 -0400 From: Sky2high@aol.com X-Original-Message-ID: <14c9.34e14a10.3b0740c5@aol.com> X-Original-Date: Thu, 19 May 2011 23:57:57 EDT Subject: Re: [LML] FW: LNC2 Vibration Issues X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_14c9.34e14a10.3b0740c5_boundary" X-Mailer: AOL 9.6 sub 130 X-AOL-IP: 24.15.17.119 X-Spam-Flag:NO X-AOL-SENDER: Sky2high@aol.com --part1_14c9.34e14a10.3b0740c5_boundary Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Content-Language: en Tom, =20 Like your mechanic says - when I balanced my prop at 2600 rpm it stayed = =20 within balance limits through a range of rpm although the weight vector=20 changed somewhat. =20 One possibility is the prop pitch control is not working properly or each= =20 blade gives different lift at different rpm. =20 We all see (feel) a little vibration in flight. What do you see the=20 ailerons do when the stick is vibrating from side to side? If there is = some=20 lash in the aileron control system and the ailerons have little load on = them=20 then it doesn't take much wing wiggle to get them to move in the dead ban= d. =20 Scott Krueger =20 =20 In a message dated 5/19/2011 3:46:17 P.M. Central Daylight Time, =20 n20087@yahoo.com writes: ----Forwarded Message---- From: n20087@yahoo.com To: n20087@yahoo.com Sent: Thu May 19th, 2011 11:26 AM EDT Subject: LNC2 Vibration Issues Folks=20 I am dealing with a vexing problem which has plagued me throughout my phase 1 testing and that is, I can't get rid of vibration from my engine prop combination. I am running a Lycoming IO360/Slick Mags (non-counter weighted crank) with a new Hartzell HC-C2YK-1BF/F7666A.=20 The prop was dynamically balanced on the ground at 23" map and 2400rpm to 0.05ips. Interesting thing is the vibration increases significantly to 0.25ips at 2500RPM on the ground. When flying, I can see the ASI needle vibrate a little (+/- 0.5mm) at high power settings >19Inches and any RPM. I have not been able to measure the vibration in the air since it is difficult to mount an accelerometer in the vertical plane under the cowl but I do see the stick vibrate a little from side to side when I let it go. Some additional background: 1. The engine has accumulated 44 hours since new 2. The crank was dynamically balanced at the factory 3. When the engine was built it was tested with a club and found to be vibration free 4. The prop has a 4" extension by Sabre Industries 5. The balancing weight was mounted to the flywheel in the form of an AN3 bolt/nut (20 grams) 6. The spinner is solidly fixed to the prop and back plate and is centered=20 7. The crossover exhaust and tailpipes are fixed to the engine only 8. The cylinders are 9:1 compression 9. All cylinder compressions are even and in the 70s 10. The engine mount bolts are torqued correctly to 40-45ftlb 11. The engine does not/cannot touch the cowl When I tested the aircraft at 17,500 feet, I noted the vibration was significantly less pronounced or non-existent due to the low power output. I noticed the same thing in cruise decent at 18 inches or lower. Talking to the prop balancing mechanic, he stated that it is unusual for balance to be ok at 2400 RPM but to be significantly different at 2500RPM+. =20 I would be very grateful for any help and assistance from anybody with knowledge or experience in correcting vibration issues such as the one I described above Thanks Tom =20 ----Forwarded Message---- From: n20087@yahoo.com To: n20087@yahoo.com To: n20087@yahoo.com Sent: Thu May 19th, 2011 11:26 AM EDT Subject: LNC2 Vibration Issues Folks =20 I am dealing with a vexing problem which has plagued me throughout my=20 phase 1 testing and that is, I can=E2=80=99t get rid of vibration from my= engine prop=20 combination. I am running a Lycoming IO360/Slick Mags (non-counter weigh= ted=20 crank) with a new Hartzell HC-C2YK-1BF/F7666A. =20 The prop was dynamically balanced on the ground at 23=E2=80=9D map and 24= 00rpm to=20 0.05ips. Interesting thing is the vibration increases significantly to= =20 0.25ips at 2500RPM on the ground. When flying, I can see the ASI needle= =20 vibrate a little (+/- 0.5mm) at high power settings >19Inches and any RPM= . I=20 have not been able to measure the vibration in the air since it is=20 difficult to mount an accelerometer in the vertical plane under the cowl= but I do=20 see the stick vibrate a little from side to side when I let it go.=20 Some additional background:=20 1. The engine has accumulated 44 hours since new=20 2. The crank was dynamically balanced at the factory=20 3. When the engine was built it was tested with a club and found to= =20 be vibration free=20 4. The prop has a 4=E2=80=9D extension by Sabre Industries=20 5. The balancing weight was mounted to the flywheel in the form of= =20 an AN3 bolt/nut (20 grams)=20 6. The spinner is solidly fixed to the prop and back plate and is= =20 centered =20 7. The crossover exhaust and tailpipes are fixed to the engine onl= y=20 8. The cylinders are 9:1 compression=20 9. All cylinder compressions are even and in the 70s=20 10. The engine mount bolts are torqued correctly to 40-45ftlb=20 11. The engine does not/cannot touch the cowl=20 When I tested the aircraft at 17,500 feet, I noted the vibration was=20 significantly less pronounced or non-existent due to the low power output= . I=20 noticed the same thing in cruise decent at 18 inches or lower. Talking= to=20 the prop balancing mechanic, he stated that it is unusual for balance to= be=20 ok at 2400 RPM but to be significantly different at 2500RPM+. =20 I would be very grateful for any help and assistance from anybody with=20 knowledge or experience in correcting vibration issues such as the one I= =20 described above=20 Thanks=20 Tom =20 -- For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.ht= ml --part1_14c9.34e14a10.3b0740c5_boundary Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Content-Language: en <= FONT id=3Drole_document color=3D#000000 size=3D2 face=3DArial>
Tom,
 
Like your mechanic says - when I balanced my prop at 2600 rpm it stay= ed=20 within balance limits through a range of rpm although the weight vector ch= anged=20 somewhat.
 
One possibility is the prop pitch control is not working properly or= each=20 blade gives different lift at different rpm.
 
We all see (feel) a little vibration in flight.  What do yo= u see=20 the ailerons do when the stick is vibrating from side to side?  If th= ere is=20 some lash in the aileron control system and the ailerons have little load= on=20 them then it doesn't take much wing wiggle to get them to move in the dead= =20 band.
 
Scott Krueger
 
In a message dated 5/19/2011 3:46:17 P.M. Central Daylight Time,=20 n20087@yahoo.com writes:


----Forwarded Message----
From= : n20087@yahoo.com
To:=20 n20087@yahoo.com
Sent: Thu May 19th, 2011 11:26 AM EDT
Subject: LN= C2=20 Vibration Issues

Folks

I am dealing with a vexing problem= which=20 has plagued me throughout my
phase 1 testing and that is, I can't get= rid=20 of vibration from my engine
prop combination.  I am running a Ly= coming=20 IO360/Slick Mags (non-counter
weighted crank) with a new Hartzell=20 HC-C2YK-1BF/F7666A.

The prop was dynamically balanced on the gro= und at=20 23" map and 2400rpm
to 0.05ips.  Interesting thing is the vibrat= ion=20 increases significantly
to 0.25ips at 2500RPM on the ground.  Wh= en=20 flying, I can see the ASI
needle vibrate a little (+/- 0.5mm) at high= power=20 settings >19Inches and
any RPM.    I have not been able= to=20 measure the vibration in the air
since it is difficult to mount an=20 accelerometer in the vertical plane
under the cowl but I do see the= stick=20 vibrate a little from side to side
when I let it go.

Some addi= tional=20 background:

1.       The engine has accumulat= ed 44=20 hours since new

2.       The crank was dynami= cally=20 balanced at the factory

3.       When the eng= ine=20 was built it was tested with a club and found
to be vibration=20 free

4.       The prop has a 4" extension by= Sabre=20 Industries

5.       The balancing weight was= =20 mounted to the flywheel in the form of
an AN3 bolt/nut (20=20 grams)

6.       The spinner is solidly fixed= to the=20 prop and back plate and is
centered

7.     &nb= sp;=20 The crossover exhaust and tailpipes are fixed to the=20 engine
only

8.       The cylinders are 9:1= =20 compression

9.       All cylinder compression= s are=20 even and in the 70s

10.   The engine mount bolts are to= rqued=20 correctly to 40-45ftlb

11.   The engine does not/cannot= touch=20 the cowl

When I tested the aircraft at 17,500 feet, I noted the= =20 vibration was
significantly less pronounced or non-existent due to th= e low=20 power
output.  I noticed the same thing in cruise decent at 18= inches=20 or
lower.  Talking to the prop balancing mechanic, he stated tha= t it=20 is
unusual for balance to be ok at 2400 RPM but to be=20 significantly
different at 2500RPM+. 

I would be very gr= ateful=20 for any help and assistance from anybody with
knowledge or experience= in=20 correcting vibration issues such as the one I
described=20 above



Thanks



Tom=20







----Forwarded Message----

From:=20 n20087@yahoo.com
To: n20087@yahoo.com
To:=20 n20087@yahoo.com
Sent: Thu May 19th, 2011 11:26 AM=20 EDT
Subject: LNC2 Vibration Issues

Folks

I am dealing with a vexing problem which has plague= d me=20 throughout my phase 1 testing and that is, I can=E2=80=99t get rid of vi= bration from=20 my engine prop combination.  I am running a Lycoming IO360/Slick Ma= gs=20 (non-counter weighted crank) with a new Hartzell HC-C2YK-1BF/F7666A.

The prop was dynamically balanced on the ground at= 23=E2=80=9D map=20 and 2400rpm to 0.05ips.  Interesting thing is the vibration increas= es=20 significantly to 0.25ips at 2500RPM on the ground.  When flying, I= can=20 see the ASI needle vibrate a little (+/- 0.5mm) at high power settings= =20 >19Inches and any RPM.    I have not been able to meas= ure=20 the vibration in the air since it is difficult to mount an accelerometer= in=20 the vertical plane under the cowl but I do see the stick vibrate a littl= e from=20 side to side when I let it go.

Some additional background:

1.      =20 The engine has accumulated 44 hours since new

2.      =20 The crank was dynamically balanced at the factory

3.      =20 When the engine was built it was tested with a club and fo= und to=20 be vibration free

4.      =20 The prop has a 4=E2=80=9D extension by Sabre Industries

5.      =20 The balancing weight was mounted to the flywheel in the fo= rm of=20 an AN3 bolt/nut (20 grams)

6.      =20 The spinner is solidly fixed to the prop and back plate an= d is=20 centered

7.      =20 The crossover exhaust and tailpipes are fixed to the engin= e=20 only

8.      =20 The cylinders are 9:1 compression

9.      =20 All cylinder compressions are even and in the 70s

10.   The engine=20 mount bolts are torqued correctly to 40-45ftlb

11.   The engine does=20 not/cannot touch the cowl

When I tested the aircraft at 17,500 feet, I noted= the=20 vibration was significantly less pronounced or non-existent due to the= low=20 power output.  I noticed the same thing in cruise decent at 18 inch= es or=20 lower.  Talking to the prop balancing mechanic, he stated that it= is=20 unusual for balance to be ok at 2400 RPM but to be significantly differe= nt at=20 2500RPM+. 

I would be very grateful for any help and assistanc= e from=20 anybody with knowledge or experience in correcting vibration issues such= as=20 the one I described above

 

Thanks

 

Tom

 



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