The Kronos Flyer design consists
of four aluminum booms sandwiched
between two pieces of 1/8" Baltic
birch plywood as shown in Figure 2.
The power distribution board and
ESCs are placed on these platforms.
The motors are mounted on a small
piece of the same plywood, and are
attached to the end of each boom.
A third platform is added that will
allow you to attach your flight
controller. A set of helicopter landing
skids are added to the bottom of the
The aluminum booms are made
from a single piece of 1/2" x 96" C-Channel. Each boom is cut to a length
of 9-5/8". You will be able to get two
complete sets of booms out of the
96" C-Channel. This will get you some
backup parts in the case of a very bad
C-Channel can be purchased at
most home centers. You can use a jig
saw, miter saw, reciprocating saw, or
hack saw to cut the booms to length.
The holes in the booms are all 9/64"
All the plywood pieces are cut
from a single 12" x 24" of Baltic birch
hobby plywood. These sheets can be
purchased online or from most craft
stores. The two lower platforms are 6"
x 6". The upper platform is 5-1/2" x 5-
1/2". The four motor mounts are 1-
1/2" x 2-1/2".
You will need a small handsaw, jig
saw, miter saw, or scroll saw to cut
the plywood pieces. The holes cut into
the plywood pieces are 9/64", 1/4",
and 1" in diameter. The 1" holes
should be cut with a forstner bit or
If you can't cut the plywood
pieces yourself, I will be offering a
laser cut set of all the platform and
motor mount parts. The set has a
couple upgrades and includes a wood
template that can be used as a guide
to drill the booms. The hardware
(shown in Figure 3) is mostly
standard #6 machine screws, and can
be purchased at most home centers
and hardware stores. You will need:
• Four #6 spacers 1/2" long
• 16 #4-40 x 1/2" machine screws
• 16 #4-40 locknuts
• 20 medium-sized tie wraps
• Two Velcro™ straps (to hold the
• Four #6-32 x 2" machine screws
• Four #6-32 x 1-1/2" machine
• 12 #6-32 x 1" machine screws
• 50 #6 washers
• 36 #6 hex nuts
Depending on where you get the
hardware, you should be able to build
the frame for less than $50, with
parts to spare.
SERVO 12.2012 45