William=0Ajust a bit more ignorant than me! The wing spars stop the wings f
olding up, (or down), the rear lift pins take the weight of the fuselage=0A
into the wings and stop them folding forwards at high G loading, (that's no
ne intuitive isn't it?) the front pins carry the resat of the fuse weight i
nto the wings.=0AThe spars don't need to be tied the the fuselage.=0AGraham
=0A=0A=0A=0A=0A________________________________=0A From: William Daniell <w
daniell.longport@gmail.com>=0ATo: 'Pete' <peterz@zutrasoft.com>; europa-lis
t@matronics.com =0ASent: Friday, 7 June 2013, 18:05=0ASubject: RE: Europa-L
ist: You'll Cry Pip Pins=0A =0A=0A=0AWell I damned, I=99d never have
thought that.=C2- Those thick spars look like they should be supporting t
he aircraft but the weedy looking fuze pins are actually do all the (liftin
g) work. =C2-So the spars=99 main job is to prevent the wings foldi
ng forward or back?=0A=C2-=0ASo the really important thing is to keep the
spars together not tie the spars into the fuze?=0A=C2-=0AI am woefully i
gnorant.=0A=C2-=0AWill=0A=C2-=0AFrom:Pete [mailto:peterz@zutrasoft.com]
=0ASent: Friday, June 07, 2013 10:56=0ATo: europa-list@matronics.com=0ACc:
wdaniell.longport@gmail.com=0ASubject: Re: Europa-List: You'll Cry Pip Pin
s=0A=C2-=0AAll the lifting loads are taken by the lift pins on the side o
f the fuse. The pip pins function only to tie the spars together and keep t
he wings from folding up under G.=0A=C2-=0AThe geometry is such that when
the main spars are flexing under load, the pip pin locations on the spars
move downward relative to the lift pins at the side of the fuse (as the lif
t pins are further out along the radius of the flexing spars), so the net r
esult is that the pip pins actually push DOWNWARDS on the seat back under h
igh positive G's.....totally counter productive. =C2-The seat back bushes
should be clearance vertically IMHO to avoid this situation.=0A=C2-=0ATh
e seat back bushes may however provide some (weak?) support in keeping the
pip pins from twisting out of the spars under their asymmetrical=C2-twist
ing load. =C2-Many gliders use fork-spar arrangements to avoid this.=0A
=C2-=0ACheers,=0APete=0AA239=0A=0AOn Jun 7, 2013, at 9:45 AM, "William Da
niell" <wdaniell.longport@gmail.com> wrote:=0AGraham=0A>=C2-=0A>I am very
interested by this statement .so as I understand it the spars are
the main load bearing structure in the airpcraft if the seat back
bush does not do the this what does?=C2- How does the motorglider work?
=0A>=C2-=0A>Will=0A>=C2-=0A>From:owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of GRAHAM SINGLE
TON=0A>Sent: Friday, June 07, 2013 04:42=0A>To: europa-list@matronics.com
=0A>Subject: Re: Europa-List: You'll Cry Pip Pins=0A>=C2-=0A>Frans=0A>The
pip pin on the port side is there to prevent the starboard spar from twist
ing away from the =0A>port spar under high load. The starboard side has no
need of retention because the overlapping =0A>spar provides that function.
=0A>Strictly speaking the bush in the seat back bulkhead is of no value, in
fact it increases the load on the spars.=0A>Be better without it as per th
e motor glider. (but DYOR)=0A>Graham=0A>=C2-=0A>=C2-=0A>=0A>___________
_____________________=0A>=0A>From:Frans Veldman <frans@privatepilots.nl>=0A
>To: europa-list@matronics.com =0A>Sent: Friday, 7 June 2013, 9:07=0A>Subje
ct: Re: Europa-List: You'll Cry Pip Pins=0A>=0A>--> Europa-List message pos
ted by: Frans Veldman <frans@privatepilots.nl>=0A>=0A>On 06/07/2013 09:40 A
M, Tony Renshaw wrote:=0A>=0A>>=C2- Talking about pip pins, does anyone s
ee any merit in using two of the Port pip pins, another for the Std spar to
o?=0A>=0A>If I recall correctly, there was some technical reason why both p
ip pins=0A>are different. I forgot the details, but this discussion has bee
n held=0A>before and someone with insight argued why using a pip pin on the
=0A>starboard side was not such a good idea. It had something to do with th
e=0A>different arrangement and thus different torsional loads on the=0A>sta
rboard side because the spars overlay "the other way around". The pin=0A>ha
d to be longer there to allow some movement, and because it needs to=0A>hav
e some play a pip pin can not be used (unless you make it longer than=0A>it
should be but then you need an additional retaining mechanism which=0A>of
course negates the whole idea of using a pip pin in the first place.)=0A>
=0A>Although I have modified my aircraft quite a lot, this is an area where
=0A>I am shy to deviate from the build plan, as it is one of the most=0A>cr
itical structural area's. As all of the other pins are pip pins my bet=0A>i
s that there must have been a reason why to use a different arrangement=0A>
on this specific pin. Surely it can't be because it was cheaper or so,=0A>o
r the designer was short of one pip pin and decided to wo==C2- --> http
://www.matronics.com/Navigator?Europa-List=0A>_ref="http://forums.matroni
cs.com/" target="_blank">http://forums.matronbsp; Thank you for your gene
rous nbsp; =C2- =C2- =C2- =C2- =C2- =C2- -Matt Dralle, List Adm
in.=0A>=0A>=0A>=0A>=0A>=0A>=0A>=C2-=0A>=C2-=0A>http://www.matronics.com
/Navigator?Europa-List=0A><=C2-=C2-=C2-=C2-=C2-=C2-=C2-=C2-
=C2-=C2-=C2-- MATRONICS WEB FORUMS -=0A>http://forums.matronics.com
=0A>http://www.matronics.com/contribution=0A>=C2-=0A>=C2-=0A>=C2-=0A>
http://www.matronics.com/Navigator?Europa-List=0A>http://forums.matronics.c
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