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Trials & Tribulations of SR Building!! Read: rivet short

Posted: Fri Feb 17, 2012 10:04 pm
by Wayne G. O'Shea
HI everyone!

While I already posted the two attached messages to the list back on the
18th and 19th, I thought they were important enough that I should repost for
those SR builders that may not have received them. I was receiving messages
all along, although somewhat delayed, and just figured nobody had any need
to respond to these posts.

All pictures refered to are in the SR tail feathers section or change the
new counter to 14 days and hit "new"!

Cheers,
Wayne

----- Original Message -----
From: "Wayne G. O'Shea" <oifa@irishfield.on.ca>
To: "Murphy Rebel Builders List" <murphy-rebel@dcsol.com>
Sent: Monday, March 18, 2002 8:28 PM
Subject: Trials & Tribulations of SR Building!! Read: rivet shortage and
elevator to fin clearance

Hello to all the hard working SR builders out there. I have two things to
add to your misery today, but better now than when you are further along
or
putting something together with proseal and run out! Don't shot the
messenger! Just trying to make your lives easier by telling you now!

First off, the whole time I was assembling the tailfeathers with the 3500
upgrades I kept looking at the supplied bag of 2200 RV1512 rivets and
thinking to myself there wasn't a hope in h-e-double hockey sticks that
would be enough to do all the mods. I spent about 3 1/2 hours of my time,
on
Friday, doing a rivet count and passed it on to Brian to update the
shipping
quantities for future shipments and to confirm the shortage on the
builders
behalf.

I believe he has already instructed Elaine on the amounts to "top up" for
anyone that has already bought a 3500 upgrade kit for their 2500. I don't
know the quantities that the 3500 complete kit gets shipped with, but
would
presume the same. QB guys, I don't know your situation with a half solid,
half pull riveted aircraft.

If anything I have probably come up a little short on the count, but keep
in
mind you can also use some of the 250 RV4514 c/s rivets in spots like the
leading edge root rib, where the fairing will sit in place of RV1512's.
Still going to be way short though. Here are the numbers I came up with as
a
minimum requirement and I have a feeling there are possibly some more
RV1613's required for the side doubler upgrades at the top motor mount
"bath
tub" fittings and probably some other places I haven't even looked at yet
(I'm sure a 100 more than my count would go in a hurray!). I have just
pasted in, below, the list I sent Brian. In addition to these numbers you
will also find that the Stab CAD drawing shows 82 RV4412 1/8" rivets and
only 70 are supplied. I had lots of RV4412's around, but if you don't why
not drill up to 5/32 on some of the C/S ones and use the RV4514's or ask
MAM
for the dozen 1/8" RV4412's. I didn't bother counting 1/8" RV1410's as
there
was always extra around when building a plain Rebel and I am assuming the
same on the SR (but could be wrong).

Location 5/32 (RV1512) 3/16 (RV1613)
Wing .063
doubler (both) 1250 206
Root doubler
.063 strap (both) 64 0
B. Skin Front
Spar (both) 34 74
T. Skin Front
Spar (both) outboard
of .063 doubler 94 0
B. Skin Main
Spar (both) 200 144
B. Skin Stringers
2 stringer each wing 0 88
Rear Spar doubler
approx 120/wing 240 0
Nose rib plate (both) 30 0
Total for both wings 1912 512

Fin upgrade 168 3
Rudder upgrade 20 4
Stab upgrades 484 16
Elevator upgrade 180 14
Total tail feathers 852 37

Fuselage door sills 0 184
Fuselage Fus-710's 0 34
Total Fuselage upgrades 0 218

Total rivets needed 2764 767
Rivets supplied 2200 525 (bag 475
+
bag 50)
Amount presumably short 564 242

The other <important> news is that Brian has found another interference
problem, while assembling a new Quick Build at the factory, between the
elevator and the fin post in the spar cap area that some of us have
recently
so proudly put together for the "last" time. This is happening on the 3500
upgraded elevator only, for some reason that is yet to be totally figured
out what has changed. The elevator, where we have reinforced it with the
"strap", is interfering with the spar cap and not leaving the 1/4"
clearance
that Brian wants. He sent me 6 pictures of were he has "hacked" out some
material from the spar caps. SO much material in fact that he felt that
.063
angles were needed on the back side of the fin post were the spar doubler
overlap rivet row goes. IF you have to be as drastic to get the clearance
as
Brian's QB this is the only fix possible on a completed Airframe at this
time. What I would suggest, if possible is to get your elevator and stab
in
there and mounted before you do final riveting on the fin spar cap area so
you know what you need to do before riveting. I unfortunately just put
this
all together late last week. I am going ignore my customers Rebel tomorrow
and try and position my stab/elevator in there and see what I have for
clearance, if any, and will share some dimensions after I have done that.
Quick measurements look like mine might be fine or just need to be trimmed
back to the fwd rivet row holding the two spar caps together (but I may be
wrong!). Just thought I should get this out to you in case there is anyone
with rivet gun in hand ready to put this together, before you end up
taking
it apart again. Will upload the pics Brian sent me to tailfeathers
tonight.
Ignore the spacer under the lower fin hinge in the pictures. Brian was
just
"playing" and this is not a modification!

Smile guys/gals, nothing else will do you any good!
Wayne G. O'Shea
www.irishfield.on.ca

Hello again! Just want to clarify my message from yesterday. It's not the
strap that interferes, it is the inboard elevator ribs that are tight
against the spar caps on each side (like your legs wrapped around a horse!)
that are keeping it from moving. I spent about 4 hours today putting my
elevator and stab onto the fuselage to sort things out and see if it was
just a QB fluke in Chilliwack or effecting the entire fleet. Considering I
am working on Serial #17 I would now guess the whole fleet. The combination
of the extra .080" that the hinges are moved rearward on the stab after the
3500 upgrade and the additional .063 per side on the spar caps (old ones
where .032 x 2, new ones .063 x 2) has apparently taken any clearance away.
I still think even the 2500's out there must be awfully close.

**UPLOADED PICTURE TO THE SITE FILES OF THE "CONTACT".**

At this point the current, but still UNOFFICIAL fix is to cut out the spar
caps (as shown in the pics I uploaded yesterday) and then add .063 angle to
the rear side of the post to put the strength back, on completed airframes.

I had another thought today that it would be very easy for someone that
hasn't finished off their elevator upgrades yet. That is to trim the
elevator skin back on the inboard ribs enough to remove the existing rivet
holes. Then install the upgrade ribs the approximate 1/2" further outboard
than they were before. This will give lots of clearance and I am thinking of
taking this route even though my elevator is totally closed.

I am in daily contact with Brian on this one so don't everyone bombard him
with extra e-mail that will just slow him down with the final fix. I will
pass on the final verdict, when I have it from MAM, for all of you to read
here.

I wouldn't do anything at this point guys/gals and would work on something
else until the final decisions are made. Just don't want anyone that is
ready to close these things up to proceed and then have to tear them apart
again.

Cheers,
Wayne G. O'Shea
www.irishfield.on.ca





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