Pitts 12 EP
The lower wing’s mounting bolt hole must be drilled (above left). Mark the blind nut’s position on the fuselage, measure out 0.65 in. from the T.E. and drill. Use a dull hot knife (above right) to cut away the covering from areas to be glued, so as
not to damage the wood underneath. Cut the control horn’s pegs level with the tops of the stab and ailerons. Use a high-speed rotary tool (below left) to countersink the pegs slightly. Cover pegs with some scrap covering (below right).
40 bolts. The wheel pants are too small for the supplied wheels. If you are flying from grass runways, forget them and also use larger, 2-inch wheels. But pants do look great so, for paved runways, enlarge the opening until the wheels rotate freely. Although there are blind nuts mounted in
a “firewall”, these are not for the electric mo- tor. There is a glow version of this airplane and those bolts may be for that purpose. The true firewall is not pre-drilled for the motor mount. But there is a center hole in the fire- wall that exactly matches the rear motor bearing. Install the motor mount, place the
motor inside that hole and mark the mount- ing holes. BP made this job easy. Remove the motor, enlarge the firewall hole about 1⁄16 inch and assemble the plywood motor mount using epoxy. Epoxy the mount to the fuse- lage box. Be careful that the right thrust points “right-wards”. The cowl fastening blocks are factory in-
stalled but the cowl is not predrilled. Use the “ole tape method” to locate the mounting block locations (see photo). Do not enlarge the small propeller hole prior to cowl instal- lation. Use the hole to center the cowl around the motor shaft and make sure the
fuselage trim matches the cowl’s. Re-posi- tion the tape, holding the cowl in place. Then drill the mounting holes one at a time; installing screws as you go. Finally, enlarge the cowl opening to about the motor’s diam- eter for cooling.
Setup Getting the proper Center of Gravity (c.g.)
is always important for any aircraft. But for the Pitts 12 EP, it is critical. The most for- ward recommended c.g. is 70mm back on the top wing (requiring 2 ounces of weight up front). Note that this c.g. is actually for 3-D
Level the wing saddle, apply 12-minute epoxy into the fuselage slots and insert the stab. Make sure the stab is precisely parallel with the wing saddle. Put
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everything as far forward as possible. The 60-Amp ESC (above right) nestles nicely on the motor mount’s underside.
JULY 2012
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