In re: 1.
If I understand you correctly you have a WIDE gap to fill between the W27
assembly and the fuselage. If you followed instructions you may be deep in
something you rather not be in. I say "may" because the pins supplied with
my kit (A070, one of the first XS kits) had the pip pin hole drilled way too
close to the wing root, and had I bonded that pin into the wing root when
instructed, I would not even have been able to get the pip pin into the
hole. Fortunately I had the pin in place, but not bonded in place, when I
began installing W26 & W27, and I discovered that the hole was so close to
the wing root that it was not possible to mate the W26 assembly to the wing
pin. The replacement pins supplied by Europa were drilled further from the
threaded end of the pin. Obviously the "relocated" pip pin holes put the
W26 assembly closer to the fuselage. If your pip pin hole is too close to
the wing root and the pin is already bonded to the wing root, I am not sure
what to recommend other than to check with Andy or Neville. You may need to
remove the pin.
In re: 2.
Sorry, but I have no useful comments.
In re: 3.
This sounds entirely too familiar, but you may be luckier than I. First
check that there is no epoxy inside any of the wing spar bushings. The
factory was a bit sloppy in making my wings so there was a some in each
bushing. It doesn't take much, and it is hard to see (clear epoxy in a
black hole), especially since it never occurred to me to check for sloppy
work. Unfortunately, cleaning out the bushings was not sufficient to get
things to fit. My XS wings fit fine, but ONLY one at a time, and the two
wing spars will accept both spar pins as long as the wings are not in the
fuselage. There seems to be a slight difference in spacing, wing to wing,
but I have an additional greater error in the location or alignment of the
seat back bushings, and it may be that both the alignment and spacing are in
error. I barely have a big enough hammer to fit the spar pins with both
wings in place. I attribute this to the fact that my early XS project was
built out of sequence because when I was ready to continue, the wings were
not available so I built the fuselage first and used two factory supplied
dummy spars for bonding the bushings into the seat backs. That's right, two
dummy spars, because the first one did not seem right so I asked for a
replacement. The centerline distance between the holes was not the same, so
I arbitrarily picked the second one and used it. BIG MISTAKE. To see how
badly the alignment really was I machined several dummy spar pins at various
undersize diameters to see what would fit. At about .050 inch / .013 mm
undersize the dummy spar pins fit without needing the big hammer.
Conclusion: I will remove both seat back bushings and replace them, this
time with both wings in place, because my preference is to avoid making any
changes in the factory made wing spars. I have yet to do this because I am
waiting until I have the landing gear installed (this is a Tri-Gear, with
mains in place and the nose gear is almost finished) so that the fuselage
will stay in place while fitting the wings.
Best regards,
Rob Housman
A070
-----Original Message-----
Behalf Of Chuck Popenoe
Subject: Re: Wing angle of incidence
Dear Collective Wisdom-
I'm about to attach the lift pin sockets to my Classic (with MTOW mod) and
have a couple of questions:
1. The manual states that you may need plywood shims under the W26 & W27
sockets. The gap between the fuselage side and the sockets are about 12 mm
with the greatest one 14 mm. This seems excessive, but that's what they
measure. Is this normal? Also, the manual doesn't mention it, but I assume
that you have to grind a relief in the root rib flange to allow insertion
of the pip pin.
2. The washout of the two wings differs! (with my meticulous--read SLOW--
building, I can't figure how this happened!!!). The 70% span starboard wing
incidence measures 1.4 deg. when the root is at 2.5 deg. Not bad! But when
the port wing 70% span section is set for 1.5 deg. its root incidence is 2.1
deg. Much less twist. So, I programmed an Excel spreadsheet to sum the
sectional lifts and moments at 1 ft. intervals, and diddled the incidence
until
the lift moments of the two wings balanced. The best result is when the
stbd.
wing is set for 2.55 deg. at the root, which gives 1.45 deg. at 70%, and the
port wing root at 2.1 deg., which gives 1.5 deg. at 70% span. The sums of
the lift-moments are exactly equal with this setup. Any comments pro or
con?
3. Now, the tough problem--it is REALLY hard getting the spar pins in! I had
easy pin insertion before converting to the MTOW 1/2" pins and bushings. I
very carefully transferred the geometry to the new bushings, using 1/2"
bolts
to cast in place the new bushings using the old bushings as jigs. The two
wings
alone allow easy pin insertion. When I insert the port wing alone, the pins
slide
in with no problem. I then slide in the stbd. wing and the port pin--no
problem. Then, the stbd. pip pin gives me fits getting it in, even with
grease,
etc. I can barely get it inserted, but the pin will barely rotate once it
is in. Way too tight! I'm afraid that I will never be able to rig the
wings
once all of the lift pins, flap pins, etc. are in place. I believe that the
bushing spacing must be off by a half mm or so in the stbd. wing.
I have pondered on this, and have come to the conclusion that I will have to
either remove the stbd. bushings in the wing and try recasting them in situ.
Or, another scheme would be to assemble the wings, substituting a 1/2" OD
tube for
the pip pin, brute force into into place, and insert a heating element
inside to
soften the Redux in the stbd. wing bushes, allowing some time to relieve
stresses,
i.e. to have the Redux flow or creep slightly. This seems like it might
work.
What do you think?
Thanks for any suggestions!
Pops
A036
-----Original Message-----
From: forum-owner@europaclub.org.uk
Subject: Re: Wing angle of incidence
Cleve,
Yes, unless for some reason the bushings that you glued into the module are
very out of line. Which would be hard to do. The bushings allow for at
least the required amount of play to get the 2.5 degree angle of Incidence.
Bill McClellan
A164
----- Original Message -----
From: <clevelee@cswebmail.com>
Subject: Wing angle of incidence
> Collective Wisdom,
>
> I'm about to go about setting the wing incidence. I am puzzled by an
aspect of
> the mechanics.
>
> The pin busings that were bonded into the cockpit module did not have a
specific
> wing angle of incidence associated with the installation.
>
> Does it really work, that with those bushings already bonded in place, I
can
> expect to rotate the wing spar relative to the outside of the fuselage to
obtain
> the 2 1/2 degrees incidence, and still expect the pin passing through the
> cockpit bushing to slide smoothly into the spar bushings?
>
> What am I not realizing?
>
> Thanks,
>
> Cleve Lee
> Mono XS A198 N396ST
> Detroit, MI
>
>
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