Al & Rebel & Elite Builders
Just a comment or two on Al's note. At the point where the sight tube fittings
are installed in the root rib, you can make a decent flat boss for the fittings
by first flattening the areas where the fittings go and then raising a boss a
bit bigger than the fittings. Just flattening the areas unfortunately leaves
the rib oil-canning in this area and for us made us expect to have a leak in the
sealer sooner if not later.
The remedy is to raise a nice round boss for the fitting to sit on and this is
not hard. The boss becomes part of the non-raised section of the rib. Just
take two round objects a bit bigger than the fittings (metal or hardwood would
even do) and clamp the rib between them where you want the boss and carefully
tap around the area with a round edged or soft faced hammer (autobody hammer is
good). This raises a nice flat boss for the fitting to sit on and takes out the
oil-canning in the area. I expect this applies to any of MAM's aluminum
airplanes. You will probably want to put a radius on one of the blocks to give
a good transition at the edge of the boss you create.
If you want to see the result, pop over to our web site and go to "Wings" and
scroll down 'til you come to the Fuel Tank Outlets section at
www.elite583.cjb.net
You will see that we also made provision for a float type gauge for fuel level
vs the sight glass but we put the fittings in to have the flexibility to change
our minds and to have a place to tie into for the tank vent (as described by
Wayne in an E-mail a while back). The system joins the two tanks via the top
sight gauge fitting (using a tee if you also have the sight gauges) and has a
J-tube extending through the wing fairing on one side. The MAM Elite C-GBZB has
what looks similar to this arrangement but the J-tube sticks through the cabin
roof at the centre near the front.
On the torque tube bearing supports, let's just say MAM could do better at the
design and fabrication of the parts so they would be square to the mounting
surface and in general fit without plenty of re-work. They are difficult to get
to fit on the hinge doublers Al spoke of and a real bugger to get to sit flat
and permit the torque tube to turn freely. BTW, it should not be necessary to
sand the bearings as MAM calls for if you get them mounted square, with a few
choice thoughts for MAM in the process we were able to do it.
These, CC-38, are (probably) the same ones used to support the control column in
the Rebel and maybe even the SRs. They are used for the torque tube and the
control column in the Elite and maybe the flapperon in the Rebel(?).
Answering Mike's question on riveting things together, I agree with Al, invest
in Cleco stock! Seriously, plenty of Clecos are needed and even more if you
decide to asemble as we have which is to essentially build up the wing with
Clecos then completely strip it, and debur the parts and prime them (inside)
with your choice of corrosion resistant primer. We went this way vs the "glue"
it together with MAM supplied paint after weighing the merits and even talking
to the tech rep from Cessna, they prime all the piece parts & then assembly. Of
course this is a personal decision so your mileage may vary :^)
Cheers & have fun with the project!
Dave R
elite583.cjb.net
Alan Hepburn wrote:
It's a lot easier to deburr the holes in the ribs where they meet the skin
if you can remove them from the spar. Also, some of them need Proseal, and
you don't want more sessions with that stuff than you have to. And some of
the Proseal ones have gap sealing brackets that also also interface with the
skin, which are installed when you Proseal the tank. So, just buy more
Clecos! And remember the recent advice about leaving a gap at the inboard
end of the stringers inside the tank to let any water get to the tank drain.
Major pain if you forget that (which I don't believe is in the
instructions). I didn't like the idea of bashing the root ribs flat to take
the sight glass fittings, so fitted capacitive sensors instead. Details
available for anybody who's interested.
I also found that, even with the enlarged aileron hinge doublers, there's
barely enough "meat" to do the job. I made mine about another 1/8" wider.
And the placing of the outboard torque tube bearing is fairly critical.
Suggest you cleco the bottom skin in place to accurately position the
adjacent wing rib. On the first one, I went by measurement alone, and wound
up with the horn just touching the rib. I pulled off the bearing and used
it for the root on the other wing, and used a fresh one on the first wing.
(The latter may only apply to the Elite - not sure how the Rebel differs in
this area). Also, put a doubler round the slot where the outboard aileron
horn passes through the bottom skin (this also may be Elite only).
Al Hepburn
----- Original Message -----
From: <
Mnleber@aol.com>
To: <
murphy-rebel@dcsol.com>
Sent: Thursday, July 03, 2003 8:20 PM
Subject: Rivetting Wings!!
I am in process of assembling wings and have all the ribs drilled out and
the
torque arm ready to rivet the end cap. I have a large pile of loose parts
which I'd dearly love to see fly in tight formation! When do you start
rivetting
the ribs to spar etc. Seems the manual leaves them to close to the end
which
means a lot of clecoes and a lot of movement of parts from cleco "give".
Anyone see any reason why the ribs couldn't be rivetted earlier in the
process. It worked for elevators and other control surfaces and probably
made a
better job. It is just that I'm reluctant to start rivetting only to find
something "hidden" later in the manual. So far I haven't found any
landmines.
Thanks
Mike LeBer
R683
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