Building Instructions
Landing Gear
The landing gear main legs have been
installed for checking in the factory, and
only need to be bolted into place for
completing the wheelpants and wheels.
Bolt them on from the bottom of the fuse-
lage, using four M6 x 30mm bolts into the
installed blind nuts. (see photo P1)
Fit the wheelpants to the legs. Glue the ‘U’
shaped milled plywood piece into the
recess in the wheelpants with 30 min.
epoxy, and the other 2 inside the wheel-
pants in the same position (see photos P2
and 3). Drill 6mm Ø right thru’ the carbon
leg (the dimple in the leg shows the posi-
tion) and both sides of the wheelpant.
Open up the hole in the outside surface of the wheel pant to 9mm Ø (to clear the head of the M6
bolt). Open up the hole in the inner surface of the wheelpant/plywood parts to 7.5mmØ for the
blind nut, and glue into place with a drop of CA with the spikes into the plywood ‘U’ shaped part.
The wheel axles are M6 x 70mm hardened steel bolts. The head of the bolt goes on the
outside
of the wheel, inside the wheel pant. The order of the items on the bolt is: Bolthead, washer, wheel
hub, washer, 6mm wheel collar(s), M6 nut, M6 blind nut, (plywood), carbon landing gear leg, and
finally another washer and the lock nut. You may need to adjust the thickness of the wheel col-
lar, or add a couple of extra washers to get the wheel exactly centred in the wheel pant, depend-
ing on the wheels you choose. A drop of Loctite on the M6 lock-nut is good insurance.
To keep the wheelpants at the correct angle, so that they clear the ground at the back, and flush
against the milled plywood part that is glued to the carbon leg, glue a small square (approx.
15mm x 15mm) of scrap 3mm plywood inside the wheel pant 25mm above the axle hole and
glue an M3 blind nut into it. Then secure the carbon leg to the wheel pant with an M3 bolt through
the leg. Do
not
use a bolt larger than M3, as the larger diameter hole could weaken the leg.
If you wish to stiffen the main landing gear from twisting moments you can add either 3mm ply-
wood, or better a 3mm aluminium, plate across both carbon legs inside the fuselage on the
underside
of the carbon legs. We recommend that you do this especially if you fly from rough
fields. The size of this plate should be 50mm wide x 250mm long. Drill the holes for the M6
bolts to match the holes in the carbon legs. You may need to enlarge the slots in the fuselage
a little to get the stiffening plate in.
C-ARF also have an optional tailwheel assembly for the Pitts, see more details on our website.
Remember - keep it lightweight at the tail end!
Composite-ARF Pitts S12
6
Carbonfibre landing
gear leg
120-125mm
Ø wheel
wheelpant
M6 bolthead
washer
6mm wheel
collars
washer
M6 locknut
M6 blind nut
M6 nut
2 pieces
milled plywood
WHEELPANT X-Section
