|
Auto Bilge Pump or Warning Light/Siren
This item is a handy way to guard
against your hull taking on water. The original design came
from the
Bay Area Battle Group.
The circuit can be use to
active a pump, warning light or siren. Shown to the left is a
flashing LED in a small model tug.
The circuit can be assembled
for about $5 with parts from Radio Shack.
Click here for wiring diagram |
 |
When the copper contacts detect
water the circuit is complete.
|
 |
|
Servo extension used to wire
flashing LED in removable cabin.
In later models I have used a small buzzer. On bright days it
is hard to see the led. The buzzer sounds like a smoke alarm
and can be heard across the pond. Available at Radio Shack for
about $2. |
 |
Another option is to buy an auto bilge pump like the
Boat Saver by RAM
|
Voltage Regulator
Change the voltage on your model |
|
Voltage regulators can be used for
lighting or to power accessories off the main battery. The
voltage regulator's job is to reduce a fixed voltage and drop
it to a constant lower voltage.
The use shown here is in my model
freighter "Great Laker." The model uses a 7.2 volt
battery for the main engines. The model also uses a bow
thruster. At 7.2 volts the bow thruster ran too fast even with
the speed control turned all the way down.
I added a
National
Semiconductor LM1084 5 amp 3.3 volt voltage regulator
inline. This takes the 7.2 volts and converts it to 3.3
volts.
There is no draw on the battery
unless the bow thruster motor is running. The extra 3.9 volts is
dissipated as heat so I added a small heat sink from Radio
Shack
(Cat. No. 276-1368).
The bow thruster will now work in
both forward and reverse and runs at a much slower, accurate
speed.
National
Semiconductor makes regulators available in an adjustable
version, which can set the output voltage with only two
external resistors. They are also available in three fixed
voltages: 3.3V, 5.0V and 12.0V. They can handle up to 5 amps
and are rated for over 12 volts starting voltage.
|
The LM1084 and heat sink (right) wired
between the battery before the ESC. |
|
Video of the bow thruster
in action using 7.2 volts (4.3 meg)
At this voltage the amount of thrust was not accurate and I
was concerned that the amount of vibration would damage the
thruster mount. |
|
Another video of
bow thruster
running (3.3 volts) (3.7 meg) |
|
|
Water Proof Seal
Seal the area around an access
hatch on your model boat with Liquid Electrical Tape. This
product is easily applied and can be found at any hardware
store. |
|
|
|
Wire
Clips
Keep your wiring in place with
this type of clip.
Available at Radio Shack |
|
|
|
Weight
There are many sources you can
use to add ballast. These weights come in 1/4 oz pieces and
are handy for fine tuning a model's draft.
Available at you local hobby
shop in the model air plane section. |
|
|
|
Mounting
A simple way to mount items in
your hull. The plastic pieces can be glued to a hull
with epoxy.
Radio Shack- 10mm Threaded
Stand Off, Catalog #276-1381 |
|
|
When heated the plastic will
crumbled leaving a small threaded brass fitting. |
|
|
Mounted in a hull with epoxy. |
 |
|
A plastic hull may be damaged if the
screw is tightened too much. Pop rivets (with the rivet removed
for the screw to pass through) add strength to the area
where the screw is placed through the hull. |
 |
|
Another view. |
 |
