double throw) switches are used for each motor. These
switches are wired to reverse the motor’s polarity for
driving the ROV in two directions with the same motor.
6. Using cable ties, attach the motors to the Pool Bot
frame. One motor is attached in the X axis, a second
motor is attached in the Y axis, and the third motor is
attached in the Z axis.
7. Connect the 9V battery connector to each of the correct
SPDT poles. All normally open switch poles should be
connected to the battery’s positive terminal (+) and all
normally closed switch poles should be connected to the
negative terminal (-).
8. Assemble the 9V battery connector and switches either
inside a project box or mount these components on a
scrap piece of wood.
LED Lighting System (Optional)
9. Underwater ROV lighting in a sunlit swimming pool is
not necessary, but when it’s nighttime LEDs can look
really cool. Powerful white LED lights can be embedded
inside the two jars. If you elect to add an underwater
lighting system, one LED lighting system must be
inserted into each jar.
10. Create a lighting system by connecting a white LED,
current-limiting resistor, 3.7V LiPo battery, and switch
on a small piece of scrap perforated circuit board.
When assembled, each lighting system is dropped
inside a jar.
11. Line the inside of each jar with a sleeve of black
construction paper. This paper sleeve will minimize the
amount of reflective glare that could “blind” the
underwater camera system during daytime operation.
WARNING: Be absolutely certain that you can safely turn
on each LED lighting system switch, drop the system inside
each jar, and securely attach the lid to each jar before you
launch Pool Bot. Any water that leaks inside the jar could
cause a dangerous short circuit.
NOTE: If you elect to skip the LED lighting system, you
must still install the two empty jars on Pool Bot. These jars
add to both the structural stability of the ROV and help
establish the unit’s buoyancy.
Underwater Camera System (Optional)
12. Dry-test your underwater camera system. Connect the
power and video signal cables to your closed-circuit
monitor and make sure that you are able to clearly see
approximately one meter away from the camera.
13. Wet-test your underwater camera system. Ensure that
the camera housing is watertight and that both the
power and video signal cables/connectors are
adequately waterproofed. Attach a small weight to the
camera and slowly lower it into some water. Watch the
video signal on your closed-circuit monitor; the resulting
image should be reasonably clear. Not all automobile
backup rear view camera systems (like the one utilized
here; refer to the Parts List) will work. Make sure that
your system is weatherproof.
WARNING: Make sure the power and video signal
cable connectors are not near the water during testing.
NOTE: Many automotive backup camera systems
require 12V. In order to easily and conveniently introduce
12V into the Pool Bot system, wire two 9V batteries in
series, i.e., connect the negative terminal from one 9V
connector to the positive terminal of another connector.
Route the remaining positive and negative terminals
through a 7812 voltage regulator IC. Refer to the voltage
regulator’s datasheet for connection information.
14. Attach the underwater camera system between the two
jars, aiming it forecastle (that’s forward, you land
Underwater Collection System (Optional)
15. Using cable ties, fasten an aquarium net to the
underside of the middle keel pipe on the Pool Bot
frame. This attachment point might need to be moved
during the sea worthiness test (see Testing section) for
loading ballast. If this relocation is necessary, just snip
the cable ties, load the ballast, and reattach the
aquarium net with new ties.
Analog Recovery System (Mandatory)
16. Mount the U-bolt to the midway point on Pool Bot’s
stern (that’s the ROV’s rear). Securely attach 25 feet of
50 SERVO 05.2014
Trim. Use washers for trimming Pool Bot on the two inch long
elbow support standards.