Lloyd owns asked --
> ...Coming up to bonding on the fuselage top moulding, so does anyone have
any hints/tips regarding ceiling panels?
Lloyd --
Just completed that task today. I fashioned a piece of scrap foam to fit
into the recess. To lighten it up, I routed a series dados in the foam (a la
lightening holes), micro'd it in place, and sanded it flush with the door
seal flanges after cure. Mine fills only the forward 2/3 of the recess. The
last 1/3 is a .012" aluminum sheet, epoxy-tacked into place prior to laying
up 2 layers of uni cloth with peel ply. The reason for the aluminum is to
stiffen the glass and create a hollow space to mount a $4.00, 4-inch, 4-ohm
speaker, pilot/copilot headphone jacks, plus an intercom. Yes, I know I'll
have to drill thru the foam and glass to affix door hinge attachment nuts,
but some little nylon "idiot plugs" will fill the holes. With the rear 1/3
hollow, I'll get at the nuts thru the speaker mounting hole. The 4-inch
speaker with small resonance box behind won't do much for Vivaldi, but it's
near the ears and is a headphone backup only.
I know of no commercial intercom that will fit the recess, but I will be
designing my own. Especially after paying for the 914, I'm not inclined to
pay $300 for a couple of 25-cent op amps, a $1 audio IC, and handful of
garden-variety passive components. Will save weight too, wiring the jacks,
which otherwise would be long runs of shielded stuff. RST Engineering
(www.rst-engr.com) has several circuit suggestions for intercoms published on
their site, for those so inclined.
The foam/glass/ali weighs in at about 10 ounces. I even tinted the resin
gray (using white and black epoxy pigments sold by System III Resins, et.
al.), so minimum gray finish paint will be required (trying to save weight
everywhere!). I couldn't think of an alternative arrangement that would be
much lighter and easier to do. Looks professional even.
Regards,
Fred Fillinger, A063
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