Mailing List flyrotary@lancaironline.net Message #36499
From: Bobby J. Hughes <bhughes@qnsi.net>
Subject: RE: [FlyRotary] Re: Mount offset
Date: Wed, 11 Apr 2007 15:05:18 -0600
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
 
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.

Subscribe (FEED) Subscribe (DIGEST) Subscribe (INDEX) Unsubscribe Mail to Listmaster