I called this instructable "Wind Boat" because the boat that I made generates wind to move forward.

This article shows you how to connect a two motors with four RF remote controlled relay so that the move:

- both forward,

- both reverse,

- first motor forward or reverse (not both per connection),

- second motor forward or reverse (not both per connection).

You can refer the circuit diagram.

Supplies

Components: packaging foam, masking tape, RF (radio frequency) remote control receiver (four channels), DC motors - 2, propellers - 4 (you need need spare), insulated wires, 9 V battery harness - 2, 6 V battery harness for four AA or AAA batteries or 3 V battery harness for two AA or AAA batteries, four or two AA or AAA batteries for motors, 9 V battery or 12 V battery for remote contorkl.

Tools: scissors, wire stripper, pliers, screw driver.

Optional components: solder, propeller fixtures to attach propellers to motors, 1 mm thickness metal wire, 1.5 mm thickness metal wire (to attach the battery).

Optional tools: soldering iron.

Step 1: Design the Circuit

The four relays are all remote control relays for the four channels.

"0" means relay node "2" connected to relay node "1"
"1" means relay node "2" connected to relay node "3"

Lets assume that:

- current moving from left to right (across the motor resistor) is forward

- current moving from right to left (across the motor resistor) is reverse

Sw1 Sw2 Sw3 Sw4 Motor1 Motor2

0 0 0 0 None None

1 0 0 0 Reverse None

0 1 0 0 None Forward

1 1 0 0 Reverse Forward

0 0 1 0 Forward Reverse

1 0 1 0 None Reverse

0 1 1 0 Forward None

1 1 1 0 None None

0 0 0 1 Reverse Forward

1 0 0 1 Reverse Forward

0 1 0 1 Reverse Forward

1 1 0 1 Reverse Forward

0 0 1 1 None None

1 0 1 1 None None

0 1 1 1 None None

1 1 1 1 None None

Assume that only one channel is ON at a time:

Sw1 Sw2 Sw3 Sw4 Motor1 Motor2

0 0 0 0 None None

1 0 0 0 Reverse None

0 1 0 0 None Forward

0 0 1 0 Forward Reverse

0 0 0 1 Reverse Forward

Change polarity of first motor only:

Sw1 Sw2 Sw3 Sw4 Motor1 Motor2

0 0 0 0 None None

1 0 0 0 Forward None

0 1 0 0 None Forward

0 0 1 0 Reverse Reverse

0 0 0 1 Forward Forward

Change polarity of second motor only:

Sw1 Sw2 Sw3 Sw4 Motor1 Motor2

0 0 0 0 None None

1 0 0 0 Reverse None

0 1 0 0 None Reverse

0 0 1 0 Forward Forward

0 0 0 1 Reverse Reverse

Step 2: Connect the Circuit

I connected only three channels and did not bother with the last one.

I borrowed the remove control circuit from friend. The remote control circuit was grounded by connected to two 9 V batteries in series. This was risky because the specified input is 9 V or 12 V and not 18 V (9 V * 2). However, even 12 V was not enough to turn ON the relay with my low current 9 V batteries. I also tried connecting 9 V battery in series with two AA batteries (9 V + 3 V = 12 V). However, even this was not enough because my 9 V battery was slightly discharged.

Step 3: Make the Boat

I made this boat many years ago with masking tape and packaging foam.

Step 4: Inflate the Tub

I inflated the tub a few years ago. I purchased a 1 meter diameter tub a few years ago for festivals.

I needed many buckets of water to fill the tub at half full.

Step 5: Testing

You can see my boat moving during testing.

My boat capsized a few times because it is narrow. You can see that my remove control was still working after it was dipped in water. However, I have not tested my circuit recently.