X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 10 [X] Return-Path: Received: from ug-out-1314.google.com ([66.249.92.168] verified) by logan.com (CommuniGate Pro SMTP 5.1.8) with ESMTP id 1981956 for flyrotary@lancaironline.net; Thu, 12 Apr 2007 14:46:23 -0400 Received-SPF: pass receiver=logan.com; client-ip=66.249.92.168; envelope-from=blake.lewis@gmail.com Received: by ug-out-1314.google.com with SMTP id k3so360162ugf for ; Thu, 12 Apr 2007 11:45:34 -0700 (PDT) DKIM-Signature: a=rsa-sha1; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:references; b=H1xVNVxcjB/12T8zR50KGvtF4fs2JC2LUyNYhPg67tHRpz1MRI1jd+ZvP2ciA2CfrCqlCXmSpxdNQy+wf70QcnOcVbIhUS4Kts4kztonzYIofheBcAHXY7WTxv+qrNcgesfJ6zFFsc/gNgoB4uAXLyTdJAfOjlvgdJ6u+QtW/K8= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:references; b=lfeNUGF7JnwmT9/lECaNEwTmt8Hb1rfOg13OIX0ZLu8+Z4U1r24gfBXjbvM8Qyl8fNQAh9ZmT1csAGL5dx39/n51NPQl4Ny2bxYnNZoZ5HnBE7sL1CsvGo80ODUtVii39DsqWrxve60P35TvZnrJ7aWXbavJuy406OIEgyJ27UY= Received: by 10.82.163.13 with SMTP id l13mr3059434bue.1176403534773; Thu, 12 Apr 2007 11:45:34 -0700 (PDT) Received: by 10.82.146.19 with HTTP; Thu, 12 Apr 2007 11:45:34 -0700 (PDT) Message-ID: Date: Thu, 12 Apr 2007 13:45:34 -0500 From: "Blake Lewis" To: "Rotary motors in aircraft" Subject: Re: [FlyRotary] Re: Mount offset In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_44063_23397943.1176403534636" References: ------=_Part_44063_23397943.1176403534636 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline Jerry, I don't have an oil pan.... 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 wrote: > > 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 > > On Apr 11, 2007, at 5:05 PM, Bobby J. Hughes wrote: > > > > 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. > > > 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 > > 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 47.5inches (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. > > Bobby > > > > ------------------------------ > See what's free at AOL.com . > > > > > -- Blake C. Lewis ------=_Part_44063_23397943.1176403534636 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline Jerry,
    I don't have an oil pan....
    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,   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


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

 
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.
 
 
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
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. 
 
Bobby
   


See what's free at AOL.com.





--
Blake C. Lewis

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