Assembly Problems

I have always had problems in getting the first main wing pin started.
Recently I did some checking and found that not all main wing pins are
created equal. Some come with generous tapered ends and others come
with a very sharp slope or no taper at all. My Genesis 2, for example
has a 4:1 taper while most Schempp-Hirth equipment will be sporting a
generous 10:1 taper. I reasoned the 10:1 slope would make it much
easier to get that troublesome first pin started.

I slid one pin into the fork end of my spar as it sat in the trailer
and found it went completely through the spar and stuck out the back
by a good inch. Idea, why can't I grind a more generous tapered end
onto one of my main wing pins? I would grind only on the part that
extends out the backside of the spar. What could that hurt? I removed
the handle and chucked the pin into my drill press. Then I turned ot
on and held a hand grinder, also running, against the whirling pin in
the area where I wished to extend the taper. Followed that up with a
file, then some sand paper and finally emery cloth. It came out shinny
and bright and looked like the factory had done it right in the first
place.

Result, I am now able to get my newly tapered pin started with ease. I
carefully align the forked wing then secure the tip with a 4 legged
wing stand (step ladder with legs shortened to correct height) + a
bungee strap. The tonged wing is then inserted and the lateral
adjustment of my UDO tool is left floating. I insert a 12 inch stick
(broom handle) into the right pin holes and force the two wings
together by applying an inward force on the broom handle. Next I check
for height alignment of the other pin holes and adjust for perfect
alignment by pumping my foot operated fuselage jack (hydraulic). When
the holes are exactly right, I apply a bit of grease inside where the
two bushings meet and also a tad of grease on the tapered end of my
modified pin. While pulling inward on my broom handle, I shove my
properly tapered pin in. You know what? It works! The gentle tapered
pin self aligns the two bushings and in she goes.

Flew 3.5 hours on Thursday and the wings didn't fall off, so my
grinding on the main wing pin must have been all right.

:) JJ