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 1980072 for flyrotary@lancaironline.net; Wed, 11 Apr 2007 16:05:06 -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_01C77C7D.1D66B518" Disposition-Notification-To: "Bobby J. Hughes" Subject: RE: [FlyRotary] Re: Mount offset Date: Wed, 11 Apr 2007 15:05:18 -0600 Message-ID: X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: [FlyRotary] Re: Mount offset Thread-Index: Acd8SMAylnDQB5MnRXeRdwlk2QqBdAALLSRw From: "Bobby J. Hughes" To: "Rotary motors in aircraft" This is a multi-part message in MIME format. ------_=_NextPart_001_01C77C7D.1D66B518 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable =20 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 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 .=20 ------_=_NextPart_001_01C77C7D.1D66B518 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Your=20 correct Ernest. I should have specified an RV. I think all of = the
RV's=20 are designed the same. I have read somewhere it is 1.25 = degrees.
Just=20 trying to confirm.

Bobby

The direction of the engine offset, and any fin offset would also = depend=20 on the direction of propeller rotation. The fin and engine offset must = agree.

Lynn E. Hanover

Also, you might ask your = engine=20 mount builder if he can truly resolve a quarter of a degree. = I=20 am sure he is pondering this issue and wondering the = same =20 :) Jerry

My=20 simple (hanger engineering) approach would be to draw a straight line = the=20 length of the left side tubes. This should be a known length. = Then using=20 a 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 line=20 47.5 inches (firewall to C-drive face) and repeat with a 1.25 degree = offset.=20 Measure the difference and subtract first set of=20 measurements. That should provide a good estimate for how much = shorter=20 to make the right side tubes. Washers could be use for fine tuning if = needed.=20 The flying RV10's seem to be as much as 1/2 ball out to the right = in=20 cruse. Not sure how much it would be without the offset. It does vary = with=20 airspeed. Some are installing rudder trim. Van's = mounts have=20 the offset build in. Tracy also has offset built into his RV8=20 mount. I think it is needed to make the plane fly = correctly. =20

Bobby

See what's free at AOL.com.=20

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