Yes,=0AGraham=0Ano comment!=0A=0A=0A=0A=0A________________________________
=0A From: William Daniell <wdaniell.longport@gmail.com>=0ATo: europa-list@m
atronics.com =0ASent: Friday, 7 June 2013, 21:48=0ASubject: RE: Europa-List
: You'll Cry Pip Pins=0A =0A=0A=0AWell i damned again and you=99re ri
ght it=99s not in the least intuitive. It=99s fascinating!=0A
=C2-=0ADid I understand that tie bar between the rear lift pins in the XS
is not present in the classic?=C2- If so the these folding forward force
s are merely supported by the fuselage sides.=0A=C2-=0AThanks=0A=C2-=0A
Will=0A=C2-=0AFrom:owner-europa-list-server@matronics.com [mailto:owner-e
uropa-list-server@matronics.com] On Behalf Of GRAHAM SINGLETON=0ASent: Frid
ay, June 07, 2013 15:15=0ATo: europa-list@matronics.com=0ASubject: Re: Euro
pa-List: You'll Cry Pip Pins=0A=C2-=0AWilliam=0Ajust a bit more ignorant
than me! The wing spars stop the wings folding up, (or down), the rear lift
pins take the weight of the fuselage=0Ainto the wings and stop them foldin
g forwards at high G loading, (that's none intuitive isn't it?) the front p
ins carry the resat of the fuse weight into the wings.=0AThe spars don't ne
ed to be tied the the fuselage.=0AGraham=0A=C2-=0A=C2-=0A=0A___________
_____________________=0A=0AFrom:William Daniell <wdaniell.longport@gmail.co
m>=0ATo: 'Pete' <peterz@zutrasoft.com>; europa-list@matronics.com =0ASent:
Friday, 7 June 2013, 18:05=0ASubject: RE: Europa-List: You'll Cry Pip Pins
=0A=C2-=0AWell I damned, I=99d never have thought that.=C2- Those
thick spars look like they should be supporting the aircraft but the weedy
looking fuze pins are actually do all the (lifting) work. =C2-So the spa
rs=99 main job is to prevent the wings folding forward or back?=0A=C2
-=0ASo the really important thing is to keep the spars together not tie t
he spars into the fuze?=0A=C2-=0AI am woefully ignorant.=0A=C2-=0AWill
=0A=C2-=0AFrom:Pete [mailto:peterz@zutrasoft.com] =0ASent: Friday, June 0
7, 2013 10:56=0ATo: europa-list@matronics.com=0ACc: wdaniell.longport@gmail
.com=0ASubject: Re: Europa-List: You'll Cry Pip Pins=0A=C2-=0AAll the lif
ting loads are taken by the lift pins on the side of the fuse. The pip pins
function only to tie the spars together and keep the wings from folding up
under G.=0A=C2-=0AThe geometry is such that when the main spars are flex
ing under load, the pip pin locations on the spars move downward relative t
o the lift pins at the side of the fuse (as the lift pins are further out a
long the radius of the flexing spars), so the net result is that the pip pi
ns actually push DOWNWARDS on the seat back under high positive G's.....tot
ally counter productive. =C2-The seat back bushes should be clearance ver
tically IMHO to avoid this situation.=0A=C2-=0AThe seat back bushes may h
owever provide some (weak?) support in keeping the pip pins from twisting o
ut of the spars under their asymmetrical=C2-twisting load. =C2-Many gli
ders use fork-spar arrangements to avoid this.=0A=C2-=0ACheers,=0APete=0A
A239=0A=0AOn Jun 7, 2013, at 9:45 AM, "William Daniell" <wdaniell.longport@
gmail.com> wrote:=0AGraham=0A>=C2-=0A>I am very interested by this statem
ent .so as I understand it the spars are the main load bearing str
ucture 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-lis
t-server@matronics.com] On Behalf Of GRAHAM SINGLETON=0A>Sent: Friday, June
07, 2013 04:42=0A>To: europa-list@matronics.com=0A>Subject: Re: Europa-Lis
t: You'll Cry Pip Pins=0A>=C2-=0A>Frans=0A>The pip pin on the port side i
s there to prevent the starboard spar from twisting away from the =0A>port
spar under high load. The starboard side has no need of retention because t
he overlapping =0A>spar provides that function. =0A>Strictly speaking the b
ush 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 the motor glider. (but DYOR)
=0A>Graham=0A>=C2-=0A>=C2-=0A>=0A>________________________________=0A>
=0A>From:Frans Veldman <frans@privatepilots.nl>=0A>To: europa-list@matronic
s.com =0A>Sent: Friday, 7 June 2013, 9:07=0A>Subject: Re: Europa-List: You'
ans@privatepilots.nl>=0A>=0A>On 06/07/2013 09:40 AM, Tony Renshaw wrote:=0A
>=0A>>=C2- Talking about pip pins, does anyone see any merit in using two
of the Port pip pins, another for the Std spar too?=0A>=0A>If I recall cor
rectly, there was some technical reason why both pip pins=0A>are different.
I forgot the details, but this discussion has been held=0A>before and some
one with insight argued why using a pip pin on the=0A>starboard side was no
t such a good idea. It had something to do with the=0A>different arrangemen
t and thus different torsional loads on the=0A>starboard side because the s
pars overlay "the other way around". The pin=0A>had to be longer there to a
llow some movement, and because it needs to=0A>have some play a pip pin can
not be used (unless you make it longer than=0A>it should be but then you n
eed 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 modifie
d my aircraft quite a lot, this is an area where=0A>I am shy to deviate fro
m the build plan, as it is one of the most=0A>critical structural area's. A
s all of the other pins are pip pins my bet=0A>is that there must have been
a reason why to use a different arrangement=0A>on this specific pin. Surel
y it can't be because it was cheaper or so,=0A>or the designer was short of
one pip pin and decided to wo==C2- --> http://www.matronics.com/Naviga
tor?Europa-List=0A>_ref="http://forums.matronics.com/"; target="_blank">
http://forums.matronbsp; Thank you for your generous nbsp; =C2- =C2-
=C2- =C2- =C2- =C2- -Matt Dralle, List Admin.=0A>=0A>=0A>=0A>=0A>
=0A>=C2-=0A>=C2-=0A>http://www.matronics.com/Navigator?Europa-List=0A><
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