(included in the Elec-option pack), into M4 blind nuts. Use the motor with the spinner backplate
bolted onto it, with three 1.5mm spacers tacked onto the back of the spinner backplate, to cen-
tre the motor and set the side and down thrust exactly parallel to the front face of the nose. (see
Gas and Glow engines section above for more detail).
Tack glue the nose ring to the inside of the fibreglass nose with a couple of drops of CA. A sec-
ond person to help hold everything in the correct positions during this task is very useful!
Fit the plywood part with the 3 ‘ears’ over the back of the motor, tightly, along with the rear car-
bon/ply bulkhead. Now position the rear bulkhead in the fuselage so that the plywood support
with the ‘ears’ is flush against the back surface of it, and tack it in place. Check that the spinner
backplate is still exactly parallel to the fibreglass nose, and then drill through the 3 ‘ears’ into the
rear former with a 3mm drill. Carefully remove the motor and open the holes in the carbon/ply
bulkhead to 4.5mm for the M3 blind nuts, which are fitted to the front face of the rear bulkhead
and glued in place with a little 5 min. epoxy.
Refit the motor and secure the back with M3 x 12 bolts. Check alignment again. When satisfied,
remove the motor and glue both bulkheads in
position properly with slow epoxy and milled
fibre mixture. Slight thrust line changes can be
made after trimming flights by adjusting the
holes in the 3 plywood ears. The slight flexibility
allowed by the plastic grommets used to mount
the motor to the front bulkhead will allow about
0.5 - 1° thrustline adjustment.
Don’t forget to add a drop of Loctite on all the
front and rear engine mounting bolts !
Plettenberg Xtra 25-13.
The Plettenberg motor is mounted in a similar
manner, except that there is no bulkhead in front
of the motor - as the
outside
of the motor turns.
This combination (Motor/LongGo cells and
Future speed Controller) is about 300 grams
lighter than the Hacker set-up, but also less
powerful. Generally you should use the same
methods as described above in the ‘Hacker’
installation, to set the correct sidethrust and
upthrust etc, using the spinner backplate to cen-
tre the motor and set the thrustline.
The backplate of the Plettenberg motor is
mounted onto a CNC milled 2mm carbon plate
supplied in the Elec-option pack with three M4 x
6mm bolts. The complete assembly is then bolt-
ed to the carbon/ply bulkhead using 3 plastic
grommets (with carbon washers on both sides)
and an M4 bolt through the grommet, into M4
blind nuts on the back face of the bulkhead. Fit
one carbon washer on the front of the grom-
mets, and 2 washers on the back to give clear-
Composite-ARF IMPACT
26