Carf-Models Ultra Lightning Instruction Manual page 11

The steel pin that is fitted in the nose gear retract block to connect the oleo legs is secured
with a single 6mm wheel collet on top. Make sure that the steel pin does not project thru' the
collet more than about 1 or 2mm, or it will hit the inside of the retract unit when operated.
For Main Gear Door installation - see 'Wing' section, page 19.
Nose Geardoor
You can chose to fit a single, or dual doors. The hinging
uses a similar method to the main gear doors, and the
door is easily removable for maintenance if needed. The
door is laminated from carbon/fibreglass composite, and
matches the colour of the fuselage already. It is supplied
about 1mm too big all round, and needs final sanding to fit
the door cutout. The nosegear opening in the fuselage is
also 1mm too small for final sanding. You will see a fine
line etched into the moulded parts as a guide.
If fitting a single, side-opening, door you will need to install
all 4 phenolic hinges, but if you chose to install 2 doors,
then omit the 4th (front) phenolic hinge, and cut the door
into 2 pieces. For the C-ARF gear the front door should be
about 75 - 85mm long, and the back door is closed with a
door sequencer when the gear is extended to prevent
debris being thrown into the fuselage by the nosewheel.
Sand the door and fuselage opening to exact size. With
the nosegear installed, determine the exact position of the
hinge with the tab on it for connection of the nose door
cylinder (for C-ARF gear it should be 185mm from the
back of the door). Space the other 3 hinges equally and
mark the positions. Prepare the outside of the plastic tube,
all surfaces of the phenolic hinges and the positions on the door for the phenolic hinges with a
light sanding and cleaning. Also sand a 12mm wide strip on the inside surface of the fuselage,
all around the perimeter of the door opening for a good bond of the hinge tube and fibreglass
strips later.
File 3 (or 4) small notches (2.5mm wide and 5mm deep) in the fuselage for the knuckles of the
phenolic hinges as shown in photo P4 (and above/right). Thread the phenolic hinges onto the
2mm Ø hinge wire, with lengths of the plastic tube in between - cut exactly to suit your slot
spacing (photo P5). The hinge wire is inserted from the front of the fuselage through a small
hole you must drill thru' the fibreglass flange and the 2 plywood bulkheads. With the nose
attached the hinge wire cannot come out (P8).
Tack glue the phenolic hinges and the plastic tube in place with a single drop of CA on each.
Keep the hinge wire as close to the edge of the cutout in the fuselage as possible for the
widest door opening angle, at least 85 degrees. Check operation, and sand door edges as
needed. Secure the hinge tube and hinges with epoxy and micro-balloon mixture.
Supplied are several 10mm wide strips of very thin clear fibreglass sheet, which should be
attached around the inside of the fuselage opening to form a lip for the door to sit against
when closed. Sand the fibreglass strip well, make the lips about 2 - 3mm wide, and glue on
with thin CA. You can add some small 3mm x 6mm high balsa strips around the perimeter of
(above) Balsa sticks CA'ed onto
tape to position door .
(below) Hinge wire is installed
thru' a small hole in front fuselage
flange and bulkheads.
11