Message-ID: <000501be780b$e3c0f680$22a3490c@ckrouse_ra.spk.hp.com>
Reply-To: "Curtis Krouse" <ckrouse@worldnet.att.net>
From: "Curtis Krouse" <ckrouse@worldnet.att.net>
To: <lancair.list@olsusa.com>
Subject: Aileron idler arms & GM4 main mount bracket
Date: Fri, 26 Mar 1999 20:40:04 -0800
Mime-Version: 1.0

          <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>>
          <<  Lancair Builders' Mail List  >>
          <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> 
>>
Hey all!!

This is my first post that involves a question about the actual buiding of
the 320 SFB kit!  I've actually begun building....yeehaaawww!

Here's the deal, I bought the hardware kit because I didn't want to spend
the time making all the brackets.  I'm at the point on the belly pan where I
am going to attach the aileron idler arms.  The drawing in the manual and
the main spar blueprint indicate that the distance between the two arm
control attach points is 15/16".  When I line up the hardware kit idler
arms, they line up with 1 15/16" distance between the holes.  The questions
are, did they drill the holes wrong?  Will the extra inch distance make a
difference in the controls?  Has anyone else run across this and used the 1
15/16" difference without any problems?

I do have another question about the GM4 main gear attach bracket.  The
drawings show the GM4 laying against the lower spar cap, but there are
several bids of fiberglass on top of it for the phenolic hardpoint.  Does
the extra 1/8 inch above the spar cap matter?  I'm hoping that I was not
supposed to file the bids down to get closer to the cap......I didn't do
that, but the bracket is definitely not flush with the cap.

Am I going to run across things like this throughout the project and just
have to use common sense?  Or are all these measurements really critical?

Confused by happy that I'm building,

Curtis Krouse
N753K

[Glad to hear you're having fun, Curtis...

I built my own hardware so was able to mfg the aileron idlers per
the manual's spec.  I suspect that the 15/16 dimension is subject to a
bit of tolerance, the important thing is that the idlers are assembled
identically on both right and left hand sides.  Are you sure that you can't 
achieve the required dimension by swapping parts, flipping them front
to back, or something?  Seems to me that with 60 degrees between each
hole you ought to be able to get much closer to that 15/16 with a little
fiddling.  (When I made mine I fixtured the 2 parts together and drilled
the holes clocked differently from side to side so there was no chance of
mixing them up... you, unfortunately, don't have that luxury.)

As for the GM4's, _DO NOT_ sand away any of those bids that hold the
phenolic mounting block in... they are structural and there for support
to the GM4.  That little bit of extra height from the spar will be
meaningless when you come to align the gear front to back.   Never mind
the BL dimension given in the manual, BTW, when positioning the GM4's...
the important thing is that their outboard ends are flush with the
phenolic mount.  When doing mine I found that using the dimension given
in the manual moved the GM4's inboard about 1/4 inch... every fraction
you move those things inboard is a fraction more that your cockpit closeout
rib will have to be moved inboard to provide clearance between it and
the tire when everything is put together.  This admonition about flush-
with-the-phenolic at the outboard end came from the factory, BTW, I'm
just passing it along.

Hope this helps.

   <Marv>

PS... you will find more than this single occurrence of being
directed to do something one way in the manual only to find out that
there is a better or more-correct way later on.  Use common sense and 
send your questions here or to the factory when you're unsure
about anything.  It never hurts to ask just to be sure.  <M>]