Cheers:
I can't recall who started this topic, but obviously it extracted much
interest. I agree wholly with Chuck Popenoe et al, that about $100US is
the best one can do in short order locally.
What may not have been mentionned is the utility of the beast. I now
realise that reading dead horizontal within a tenth of a degree is only
one small utility. I have used it to tell me what's going on at the
other end of the wing/fuselage/cockpit when I'm aligning goodies at this
end - because of the audio beep.
Secondly, alignment can take place at any degree, so that exact
'horizontality' doesn't matter if you once have set a datum, you need
only parallel that datum to re-acquire the horizontal need.
I have always insisted on .1deg accuracy, just because there is no
other easy repeatable criterion, and it didn't seem that unattainable. I
DO know that I've measured 1.5 - 1.7 degrees disagreemant in left and
right Riggers' Angle of Incidence in commercial aircraft, and it didn't
seem to affect them any (maybe lost a knot or two here or there).
One other advantage - proof. I photo'd every setting of the
inclinometer where I thought my inspector might be questioning my
construction. Thus I can show my wingtips and root centrelines are
correctly aligned, and how accurately (Used the beep again). I also
convinced myself that an absilutely true spar was not THAT critical. If
everything on the wing is aligned at 90deg to the two mounting holes
(and I proved them parallel, then the spars can do what they like as
long as everything attached to them is in alignment.
Hope that helps cement the discussion.
Happy landings
Ferg A064
So use of the digit over the bubble is vital to me. I save the bubble
for house-building!
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