around the sides and back of the opening, projecting
about 3mm inside the opening for the door to sit on,
so that it will be flush with the outside surface of the
fuselage. The door can be secured with a small ply-
wood tongue at the front, that fits inside the fuse-
lage, and a single countersunk sheetmetal screw at
the back, into a small 3mm thick plywood tab, as
shown.
The next steps describe the fitting of a rearward re-
tracting (90°) nosegear unit. Sand the milled ply-
wood nosegear bulkhead if necessary so that it fits
snugly inside the fuselage, perpendicular to the front
cockpit flange - without deforming the fuselage
shape. You will need to sand the bottom of the bulk-
head a little, as it is milled to be large enough to in-
stall it at a 10 or 15 degree angle for the
forward-retracting gear. Position it approx. 15mm be-
hind the back of the nose door opening.
Determine the height at which your chosen retract
will have to be fixed to the bulkhead by installing the
leg and wheel and checking that it is at least 5mm
above the bottom of the fuselage in the retracted po-
sition. For a 90° SpringAir 100/300 series and 2”
wheel the bottom of the unit needs to be about 20 -
22mm up, as shown. The length of the leg, from the
top to the centre of the axle needs to be approx.
138mm (5
5
/
8
”).
Mark an accurate centreline on the bulkhead, and
secure the retract unit using 4 small bolts, and T-nuts
on the front face. Prepare the edges of the bulkhead
and the inside of the fuselage carefully for gluing.
Now cut a small slot in the bottom of the fuselage for
the noseleg, and trim it to final size and shape later,
when the nosegear is completed.
Install the bulkhead with the retract mounted on it,
and use a 90° square to set it perpendicular to the
front cockpit rail. Tack in position with 2 or 3 small
drops of thick CA, and then extend the leg and view
from the front of the fuselage to check that it is truly
vertical. When satisfied, remove the retract unit and
bond the bulkhead permanently into the fuselage
with a fillet of slow epoxy and micro-balloons on both
the front and back faces. You can reinforce this joint
with a strip of 80gram/4 oz. fibreglass and laminat-
ing epoxy if you wish.
Now trim the cockpit floor stiffening rails to length,
so that they touch the nosegear and rear cockpit
Fox Composites Co., Ltd.
30
(above) Add 1.5mm thick cross-grain
balsa strips around inside of opening.
(below) Thin fibreglass or ply strips are
added to sides & back, projecting about
3mm, for the door to sit on. Secure at
front with a ply tongue, and at the back
with a single CSK screw into a ply tab.
(above) 90° SpringAir 100 or 300 series
unit and wire leg with 2” wheel needs to
be positioned 20 - 22mm up from bot-
tom of bulkhead. Prepare edges of bulk-
head and fuselage carefully for good glue
joint. Fix retract with M3 bolts and T-nuts
on front face.
20 - 22mm
