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We have got to be ‘with it’ so I’m told,
but it’s a bit of an exaggeration.
My method is more like 80% ‘hopefully’
organic. My models are definitely biodegradable, some
quicker than others!
I build the old fashioned way using mainly wood. All the
‘oldies’ amongst you will know the various ways of building.
(Are there any young ones out there these days?) Some of you
may have entered the hobby late in life and have only used
foam or ARTF models.
I do not claim any advantages other than that wings can be
built lighter in wood than in foam. Of course, you can build
them heavier if you are not careful. No, I build with wood, just because I
enjoy doing it that way and that’s what the hobby is about!
Fuselages I usually build on a horizontal crutch made from
1/4" sq balsa which is assembled over the plan view on the
drawing. Then the half formers are assembled on top of this
and the top keel strip made from 1/16” or 3/32” sheet is
added. Before lifting this assembly off the plan I add
planking upto about 1” above the crutch. This helps keep the
structure ‘true’ when lifted from the building board.
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The whole of the fuselage
sheeting is done in planks 1/4” to 3/8” wide
from 1/16” or 3/32” sheet, tapered at the fore
and aft ends to accommodate the fuselage taper.
When the structure is removed from the board I
then add the lower half of the frames and the
keel. At this time I think about the control
runs etc. and fit these securely before
planking. When I am happy with the internals I
carry on with the planking. This can vary
between joy and tedium and back again to joy
when it is finished and sanded down. |
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The tapering of the planks
can be a bit of a hit and miss affair if you
guess at it. I suppose if you are computer
literate (I am not) you could easily develop
them with computer-aided design. You could then
draught them out on paper. I do mine like laying
carpet tiles. Having fitted the first plank
without taper I lay the next plank against it at
a fairly parallel portion of the fuselage or
maximum girth, then hold the end of the plank
down onto the structure so that it lies
naturally. To achieve this it will overlap the
preciously fitted plank. Holding it in this
position run a pencil along the edge marking the
extent of overlap onto the lower plank. Then at
regular intervals and at 90 degrees to this line
I draw lines onto both planks to create station
lines. I then remove the loose plank and measure
at each station on the fixed plank the distance
of overlap. I then transfer this measurement to
the corresponding station line on the loose
plank. This will create a series of points which
when joined will produce the cutting line for
tapering the loose plank. |
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I always finish the surface with 6oz/sq.ft glass cloth and
epoxy resin. The easiest way is to mount the fuselage in a
jig so that you can roll it around its primary axis as you
work. The jig is based on the method described by Graham
Garner in a Traplet publication. The nose and tail are
drilled on the centre line to accept a spindle mounted in
posts at each end of the jig. See the sketches below.
There is no waiting for one side to dry before you do
another. It can all be done in one operation.
The wings. I start by butt-joining sheets of 1/16” or
3/32” balsa to make sufficient area for the wing plan.
Sand smooth both faces. On the side which is to be the
inner face, I draw the structure lines, and then transfer
these with carbon paper and pencil onto the wood. I
now build the structure onto the lower sheet which I can
usually manage to do flat just packing up the sheet at the
leading edge to follow the rib contour. Any washout
needed I build in at the top skinning stage by packing up
the leading edge by the amount required at the inboard end
whilst keeping the trailing edge flat on the building board.
Doing it this way obviates a curved aileron hinge line.
On my Spiteful and Attacker models I gave the wings 2 coats
of epoxy resin only – no glass cloth, but on future models I
will at least glass cloth the leading edges. Old heather can
be quite punishing to the leading edges. On the Avro
707A that I am presently building I have glassed the entire
wing, I wonder whether it will fly? Not on the account of
the glassed wing, but because of the need to keep it on the
right side of the drag curve.
Well, that’s my method of building PSS models. Should anyone
like to build my way have a go with my Supermarine Spiteful
or Attacker - both available from the Nexus Plans Service.
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Stewart
Redfern with his O/D Attacker model |
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