<<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>>
          <<  Lancair Builders' Mail List  >>
          <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>>
>>
Ted and Curtis have raised interesting points.  I think Ted was driving at
"Think carefully before making modifications because there may be other
effects you haven't foreseen".  An example would be deleting the header tank
and running straight off the wing tanks.  If you didn't foresee the
subsequent requirement to change from 1/4 inch fuel lines to 3/8 inch you
could set yourself up for a problem.  This is a trivial example of the basic
point.

I think Curtis was driving at "The factory has told us to manufacture this
part in a particular way but this other way seems easier".  Maybe blind
rivets in pushrods isn't the best example but there are many times where the
factory approach is less desirable -- maybe you have a tool that most of us
don't have which makes the job easier, or maybe you don't have that expensive
tool that the factory has, or maybe you're more skilled at some manufacturing
technique and prefer to use that one over what the factory described, or
maybe you're stuck doing it by yourself and the four-handed approach won't
work.  So you do it a different way.

So their discussion was a little bit of "apples vs oranges" but they each
raised good issues.

Since you asked for my two cents (didn't you?), I think both approaches have
merit and risks.  The forward hinge canopy most of us use on LNC2s is the
result of a builder-developed upgrade, for example.  So are the torque tube
canopy latch and the main gear shock absorbers (both kinds).  All of these
positive changes required a fair amount of engineering, but if you can do it,
more power to you, and please let us know what you've done so we can copy it
if we want to.  (It's a shame we builders are so secretive about our
innovations, ain't it?)  But like Ted says, you might be biting off more than
you think.

Concerning alternate manufacturing techniques, I think we're fooling
ourselves if we say the factory and the FAA know all.  However, there are
standard practices that have proven themselves over time to be airworthy, and
the FAA goes to great pains to get the word out.  Having said that, there are
many manufacturing techniques that don't make sense in our garages because we
don't have the hundred-thousand-dollar tool or we don't build a jig because
we're only doing it once.  Or maybe it just seems awkward to do it that way.  
And Curtis rightfully said "I have a problem doing it that way, how about
this other way of getting it done?"

I'm fortunate to have the engineering training that allows me to say "I
understand this substitution and it's okay" in certain limited areas.  But I
think I know my limitations and often ask for advice in the other areas.  
That's why this forum, and the telephones at the factory, and the EAA
chapters and their Tech Counselors are so valuable.  Don't be bashful.

- Rob Wolf
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
LML website:   http://www.olsusa.com/Users/Mkaye/maillist.html
LML Builders' Bookstore:   http://www.buildersbooks.com/lancair

Please send your photos and drawings to marvkaye@olsusa.com.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>