X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 2 [X] Return-Path: Received: from [66.219.56.248] (HELO qnsi-xch.qnsi.net) by logan.com (CommuniGate Pro SMTP 5.1.8) with ESMTP id 1980189 for flyrotary@lancaironline.net; Wed, 11 Apr 2007 17:26:55 -0400 Received-SPF: none receiver=logan.com; client-ip=66.219.56.248; envelope-from=bhughes@qnsi.net X-MimeOLE: Produced By Microsoft Exchange V6.5.6944.0 Content-class: urn:content-classes:message Return-Receipt-To: "Bobby J. Hughes" MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----_=_NextPart_001_01C77C88.91CCFB78" Disposition-Notification-To: "Bobby J. Hughes" Subject: RE: [FlyRotary] Re: Mount offset Date: Wed, 11 Apr 2007 16:27:20 -0600 Message-ID: X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: [FlyRotary] Re: Mount offset Thread-Index: Acd8hclpmwAiFNcvSRW4wePUWhS9iQAAJ/MA From: "Bobby J. Hughes" To: "Rotary motors in aircraft" This is a multi-part message in MIME format. ------_=_NextPart_001_01C77C88.91CCFB78 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable The RV10 rotary cowl was built with the offset that was designed into the CCI mount. I will try Saturday to calculate what Fred built in. The cowl is adjustable in length (straight section by firewall) between 48.75 and 52.75 inches from firewall to back of the spinner. It will take some sanding to get it centered. =20 Bobby=20 ________________________________ From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Jerry Hey Sent: Wednesday, April 11, 2007 3:05 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Mount offset It has certainly been done that way by many. The only problem I can see is that it kicks the nose over and may not fit in the center of the cowl opening. Of course, if you are building the cowl, you can make it look good. Jerry=20 On Apr 11, 2007, at 4:56 PM, bmears9413@aol.com wrote: =09 My kit suggest to install washers between my mount and the firewall to get the thrust I need. This doesnt sound like a very good way to do it to me. Is this really the norm for adjusting thrust? =20 Bob Mears Supermarine Spitfire =20 -----Original Message----- From: jerryhey@earthlink.net To: flyrotary@lancaironline.net Sent: Wed, 11 Apr 2007 3:22 PM Subject: [FlyRotary] Re: Mount offset =09 =09 Bobby, I am sure we can get it right. I am interested in Blake's suggestion because I can do the drilling of the S-beam on the mill where I have more control. We can also do something like you have just suggested by measuring from a point on the S beam back to the firewall. And then instead of moving the motor around, I can just move the firewall. Same thing in reverse. Jerry=20 On Apr 11, 2007, at 5:05 PM, Bobby J. Hughes wrote: =20 =09 Your correct Ernest. I should have specified an RV. I think all of the RV's are designed the same. I have read somewhere it is 1.25 degrees. Just trying to confirm. =09 Bobby=20 =09 =09 The direction of the engine offset, and any fin offset would also depend on the direction of propeller rotation. The fin and engine offset must agree. =20 =20 Lynn E. Hanover Also, you might ask your engine mount builder if he can truly resolve a quarter of a degree. I am sure he is pondering this issue and wondering the same :) Jerry =09 =09 My simple (hanger engineering) approach would be to draw a straight line the length of the left side tubes. This should be a known length. Then using a protractor draw another line the same length at a 1.25 degree offset. Measure the difference at the end of the lines. Then draw a line 47.5 inches (firewall to C-drive face) and repeat with a 1.25 degree offset. Measure the difference and subtract first set of measurements. That should provide a good estimate for how much shorter to make the right side tubes. Washers could be use for fine tuning if needed. The flying RV10's seem to be as much as 1/2 ball out to the right in cruse. Not sure how much it would be without the offset. It does vary with airspeed. Some are installing rudder trim. Van's mounts have the offset build in. Tracy also has offset built into his RV8 mount. I think it is needed to make the plane fly correctly.=20 =20 Bobby =20 =09 =09 =09 =09 ________________________________ See what's free at AOL.com . =3D ________________________________ AOL now offers free email to everyone. Find out more about what's free from AOL at AOL.com . =09 ------_=_NextPart_001_01C77C88.91CCFB78 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable
The RV10 rotary cowl was built with the = offset that was=20 designed into the CCI mount. I will try Saturday to calculate what Fred = built=20 in. The cowl is adjustable in length (straight section by firewall) = between=20 48.75 and 52.75 inches from firewall to back of the spinner.  = It will=20 take some sanding to get it centered.
 
Bobby 

From: Rotary motors in aircraft=20 [mailto:flyrotary@lancaironline.net] On Behalf Of Jerry=20 Hey
Sent: Wednesday, April 11, 2007 3:05 PM
To: = Rotary=20 motors in aircraft
Subject: [FlyRotary] Re: Mount=20 offset

It has certainly been done that way by many.  The only = problem I=20 can see is that it kicks the nose over and may not fit in the center of = the cowl=20 opening.  Of course, if you are building the cowl, you can make = it =20 look good.     Jerry




On Apr 11, 2007, at 4:56 PM, bmears9413@aol.com = wrote:
My kit=20 suggest to install washers between my mount and the firewall to get = the thrust=20 I need. This doesnt sound like a very good way to do it to me. Is this = really=20 the norm for adjusting thrust?
 
Bob=20 Mears
Supermarine=20 Spitfire
 -----Original=20 Message-----
From: jerryhey@earthlink.net<= BR=20 style=3D"FONT-SIZE: 13px; FONT-FAMILY: Verdana">To: flyrotary@lancaironline.netSent: Wed, 11 Apr 2007 = 3:22=20 PM
Subject:=20 [FlyRotary] Re: Mount offset
Bobby,   I = am sure we=20 can get it right.  I am interested in Blake's suggestion because = I can do=20 the drilling of the S-beam on the mill where I have more control. =  =20  We can also do something like you have just suggested by = measuring from=20 a point on the S beam back to the firewall.    And then = instead of=20 moving the motor around, I can just move the firewall.  =  Same thing=20 in reverse.  Jerry
On Apr=20 11, 2007, at 5:05 PM, Bobby J. Hughes wrote:
 
Your correct = Ernest. I=20 should have specified an RV. I think all of theRV's are designed = the same.=20 I have read somewhere it is 1.25 degrees.Just trying to=20 confirm.
Bobby
The direction of the engine offset, = and any fin=20 offset would also depend on the direction of propeller rotation. = The fin=20 and engine offset must agree.
 
 
Lynn E. = Hanover
Also, you might ask your engine mount = builder if=20 he can truly  resolve a quarter of a degree.   I am = sure he=20 is pondering this issue  and wondering  the same  = :) =20  Jerry
My simple=20 (hanger engineering) approach would be to draw a straight line the = length=20 of the left side tubes. This should be a known length. Then = using a=20 protractor draw another line the same length at a 1.25 = degree=20 offset.  Measure the difference at the end of the lines. Then = draw a=20 line 47.5 inches (firewall to C-drive face) and repeat with a 1.25 = degree=20 offset.  Measure the difference and subtract first set = of=20  measurements. That should provide a good estimate for how = much=20 shorter to make the right side tubes. Washers could be use for = fine tuning=20 if needed. The flying RV10's seem to be as much as 1/2 = ball out to=20 the right in cruse. Not sure how much it would be without the = offset. It=20 does vary with airspeed. Some are installing rudder=20 trim.  Van's mounts have the offset build in. Tracy also = has=20 offset built into his RV8 mount. I think it is needed to = make=20 the plane fly correctly. 
 
Bobby
  
See what's free at = AOL.com.
=3D
AOL=20 now offers free email to everyone. Find out more about what's free = from AOL at=20 AOL.com.

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