Subject: Dimensions Lancair ES cowl
From: Rotary Engine
Date: 9/1/2009, 2:04 PM
To: AAA Put this in the To box


   Here is the latest with the new dimensions. Still needs some minor
   tweeks here and there.

   Paul Lamar


  Paul what is the plan to split the cowl [vertically or
  horizontally? Connection type?

  Are we just making a foam buck over which Mark is going to lay up
  glass and then
  hack out the foam?

  Jarrett

  I think it is best to split it horizontally for service reasons.

  The foam buck however could be split vertically as then you would
  have a mirror image. I can do the 3D either way.

  ops I forgot to answer the connection type.
  The bent piano hinge trick is popular.
  The top is held together with a piano hinge.
  You remove the wire to separate them.

  Paul Lamar


  Alrighty, we can split it either way.. I imagine it would be
  shorter if
  we split it vertically thru the
  spinner? I'm still a little limted in 'Z' depth so the shorter
  it is in this dim the best..

  Interior ducting can easily be done either as a buck or a female
  buck/mold. Either will take a little
  to finish as they wouldn't be true 'mold's [as in waxable..] Mind
  you I can do that as well..just
  takes more time and some more exotic materials..

  It's been a few years since I used Rhino.. does it have zebra
  curves to check the surface smoothness,
  and blends across joints [curvature continous curves across joint
  lines]?
  I'll have to send some pic's of parts I've made like this on
  the mill...  did a world record setting kayak
  two years ago...

  Jarrett

  I think we can use insulation foam and cover it with saran wrap
  and scotch tape.
  The imperfections would be easy to sand off the buck.

  The short way would be a horizontal split as the total cowl
  is only 31 inches high while it is 46 inches wide.

  No zebra curves as far as I know but people tell me it will load into
  Solid Works.

  You do the whole thing and then split it on a plain.


  Paul Lamar

 Sure Paul, I can give it a whirl... can I get you to send me what you've
 got so far [model or dim's] and I'll play w/ it from there? Your correct,
 Sw can open Rhino files directly if you want to go that route.

 Jarrett

 I need to do some more tweeking.


 Paul Lamar

Paul,

The tunnel on the firewall has straight sides.  The roof is streamlined to
encourage airflow through the tunnel.  The cowl portion is basically a
half-circle, as shown in these pictures of an ES cowl (not mine).  I feel
that my installation would benefit from slightly larger tunnels than these
in order to improve exit airflow.

Mark S.

What is the thinking on these? Theory?

It is not obvious to me.

Paul Lamar
-- 
The Rotary Engine NewsLetter. Powered by Linux.
ACRE NL web site. http://www.rotaryeng.net
Youtube key word UTUBPLEASE
Copyright 1998-2009 All world wide rights reserved.