Specifications

erated by the brushed motor.
10.1.9. Motor diode
If you are using a brushed motor, it may come with a diode which you may need to attach to
the motor. The diode looks like a black barrel with a grey stripe on one side, and two leads
coming out each end.
This diode prevents ESC damage by shunting the spikes of reverse current generated when
the brushed motor rotates. So, you put the diode on the power terminals of the brushed motor.
The end with the silver band goes on the postive terminal of the motor, and the end with no
band goes on the negative terminal of the motor.
10.1.10. Ball links
Your ball links must move freely, but not be loose. If your ball links are too tight, you can put
the ball link on the ball and gently squeeze around the edge of the ball link with a pair of slip-
joint or ball-link pliers.
If your ball links are too loose, then they can be tightened by removing them from the ball then
squeezing them gently across the face of the ball link with a pair of slip-join or ball-link pliers.
10.1.11. Motor shaft
For motors with 3.17mm shafts or larger: If your motor output shaft does not have a "flat" on
the shaft, the pinion may spin around on the shaft because the setscrew can't grip the shaft. To
put a flat on the shaft you need a Dremel with a diamond grinding tip, some masking tape, and
a plastic bag.
• Cut off about eight pieces of masking tape about 3 inches long. Take four of the pieces and
make a # pattern across the front of the motor so the # will slightly overlap the shaft. Take
the remaining four pieces and make another # across the front about 45 degrees offset
from the previous tape, making sure it slightly overlaps the shaft again. This should com-
pletely cover the front bearing and will prevent metal bits from falling in.
• Put the motor in the plastic bag, then punch a hole in the plastic with the motor shaft so the
motor shaft sticks out the bottom. Tie the back end of the plastic bag. This will prevent met-
al shavings from falling into the motor and destroying it.
• Grind a flat on the shaft using a Dremel with a diamond bit. Hold the Dremel so the metal
bits are ejected AWAY from the front bearing of the motor.
• Use some masking tape and wrap it around the shaft a few times to collect the loose metal
bits sticking to the shaft.
• Remove motor from plastic bag, being careful not to get any metal shavings into the motor.
• Remove remaining masking tape from the motor.
10.1.12. Brushless motor wires
If the wires between the ESC and brushless motor are too long, then shorten the wires from
the ESC, not the motor wires. The brushless motor wires are usually enamel-coated copper
wires from the stator windings and are difficult to solder if cut.
Helicopter Construction
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