X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 2 [X] Return-Path: Received: from elasmtp-scoter.atl.sa.earthlink.net ([209.86.89.67] verified) by logan.com (CommuniGate Pro SMTP 5.1.8) with ESMTP id 1982024 for flyrotary@lancaironline.net; Thu, 12 Apr 2007 15:25:45 -0400 Received-SPF: none receiver=logan.com; client-ip=209.86.89.67; envelope-from=jerryhey@earthlink.net DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=dk20050327; d=earthlink.net; b=d4+Yei1nal7jVo7JYQK2M/uNMnu7SwRvUHpDe1wDvDYpaKwHzXxosJxpHXKLyPfM; h=Received:Mime-Version:In-Reply-To:References:Content-Type:Message-Id:From:Subject:Date:To:X-Mailer:X-ELNK-Trace:X-Originating-IP; Received: from [71.54.80.210] (helo=[192.168.0.101]) by elasmtp-scoter.atl.sa.earthlink.net with asmtp (Exim 4.34) id 1Hc4uh-0001eR-2i for flyrotary@lancaironline.net; Thu, 12 Apr 2007 15:24:59 -0400 Mime-Version: 1.0 (Apple Message framework v752.3) In-Reply-To: References: Content-Type: multipart/alternative; boundary=Apple-Mail-1-530204079 Message-Id: <3BF3AC7C-F73C-4F6A-833E-4F0AA5390796@earthlink.net> From: Jerry Hey Subject: Re: [FlyRotary] Re: Mount offset Date: Thu, 12 Apr 2007 15:24:59 -0400 To: "Rotary motors in aircraft" X-Mailer: Apple Mail (2.752.3) X-ELNK-Trace: 8104856d7830ec6b1aa676d7e74259b7b3291a7d08dfec794da8211e1d3d70a58a9c4f1b8f6ac9c8350badd9bab72f9c350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 71.54.80.210 --Apple-Mail-1-530204079 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=ISO-8859-1; delsp=yes; format=flowed Blake, I'm not sure if they are symmetrical or not. With my trusty laser, I can set offset in just a few minutes. =20 End of story for me. The easy way with CAD is to draw a line 47 =20 inches long (in this case )and then another line starting at the =20 same point but at 1.25=BA. Then measure between the two ends. I did =20= this to verify Ernest's results which of course were correct. Jerry On Apr 12, 2007, at 2:45 PM, Blake Lewis wrote: > Jerry, > I don't have an oil pan.... > If most of the oil pan bolts are left and right symmetrical and =20= > in straight line you can flip the beam end for end and now you have =20= > a right offset equal to the left offset. The prop flange stays =20 > centered. > Blake > > On 4/11/07, Jerry Hey wrote: > Bobby, I am sure we can get it right. I am interested in Blake's =20= > suggestion because I can do the drilling of the S-beam on the mill =20 > where I have more control. We can also do something like you =20 > have just suggested by measuring from a point on the S beam back to =20= > the firewall. And then instead of moving the motor around, I can =20= > just move the firewall. Same thing in reverse. Jerry > > > On Apr 11, 2007, at 5:05 PM, Bobby J. Hughes wrote: > >> >>> Your correct Ernest. I should have specified an RV. I think all =20 >>> of the >>> RV's are designed the same. I have read somewhere it is 1.25 =20 >>> degrees. >>> Just trying to confirm. >>> >>> Bobby >>> >>> The direction of the engine offset, and any fin offset would also =20= >>> depend on the direction of propeller rotation. The fin and engine =20= >>> offset must agree. >>> >>> >>> Lynn E. Hanover >> >> Also, you might ask your engine mount builder if he can truly =20 >> resolve a quarter of a degree. I am sure he is pondering this =20 >> issue and wondering the same :) Jerry >>> My simple (hanger engineering) approach would be to draw a =20 >>> straight line the length of the left side tubes. This should be a =20= >>> known length. Then using a protractor draw another line the same =20 >>> length at a 1.25 degree offset. Measure the difference at the =20 >>> end of the lines. Then draw a line 47.5 inches (firewall to C-=20 >>> drive face) and repeat with a 1.25 degree offset. Measure the =20 >>> difference and subtract first set of measurements. That should =20 >>> provide a good estimate for how much shorter to make the right =20 >>> side tubes. Washers could be use for fine tuning if needed. The =20 >>> 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 =20 >>> vary with airspeed. Some are installing rudder trim. Van's =20 >>> mounts have the offset build in. Tracy also has offset built into =20= >>> his RV8 mount. I think it is needed to make the plane fly correctly. >>> >>> Bobby >>> >>> >>> >>> See what's free at AOL.com. >> > > > > > --=20 > Blake C. Lewis > --Apple-Mail-1-530204079 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=ISO-8859-1 =A0Blake,=A0 I'm not sure if = they are symmetrical or not. =A0

=A0 =A0With my trusty = laser, I can set=A0 offset in just a few minutes. End of story for me.=A0 = =A0 =A0The easy way=A0 with CAD is to draw a line 47 inches long=A0 (in = this case )and then another line starting at the same point but at = 1.25=BA.=A0 Then measure between the two ends.=A0 I did this to verify = Ernest's results which of course were correct.=A0 =A0=A0 =A0Jerry


=A0=A0
On Apr = 12, 2007, at 2:45 PM, Blake Lewis wrote:

Jerry,
=A0=A0=A0 I don't have an oil pan....
=A0=A0=A0= If most of the oil pan bolts are left and right symmetrical and in = straight line you can flip the beam end for end and now you have a right = offset equal to the left offset. The prop flange stays centered. =
Blake

On 4/11/07, Jerry Hey <jerryhey@earthlink.net> = wrote:
Bobby,=A0 =A0I am sure we can get it right.=A0 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. =A0 =A0We can also do = something like you have just suggested by measuring from a point on the = S beam back to the firewall. =A0 =A0And then instead of moving the motor = around, I can just move the firewall.=A0 =A0Same thing in reverse.=A0 = Jerry


On Apr 11, = 2007, at 5:05 PM, Bobby J. Hughes wrote:

=A0
=
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.

Bobby

=
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.
=A0
=A0
Lynn E. = Hanover

Also, you might ask your = engine mount builder if he can truly=A0 resolve a quarter of a degree.=A0 = =A0I am sure he is pondering this issue=A0 and wondering=A0 the same=A0 = :)=A0 =A0Jerry
My simple (hanger = engineering) approach would be to draw a straight line the length of = the left side tubes.=A0This should be a known length. Then using a = protractor draw another line=A0the same length at a=A0 1.25 degree = offset.=A0 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. =A0Measure the difference and subtract=A0first set of = =A0measurements. 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=A0out= to the right in cruse. Not sure how much it would be without the = offset. It does vary with airspeed.=A0Some are installing rudder = trim.=A0=A0Van's mounts have the offset build in. Tracy also has = offset built into his=A0RV8 mount.=A0I think it is needed to make the = plane fly correctly.=A0
=A0
=
Bobby
 =A0=A0


See what's free at AOL.com. =





-- =
Blake C. = Lewis


= --Apple-Mail-1-530204079--