Introduction: Simple Aquatic ROV/Submarine

This instructable will teach you step-by-step how to make a cheap underwater submersible!

Step 1: First, Let's Look at the Materials

The materials used in this project are:

  • 1x) Wax Toilet Bowl Seal
  • 1x) 10’ x ½” PVC Pipe
  • 1x) ½” End Cap
  • 1x) ½”x6”x2’ wood plank
  • 1x) 40’ CAT 5E Cable
  • 1x) 2’ Foam pipe insulation
  • 1x) 12v Power supply
  • 2x) ½” 45 Elbow
  • 2x) ½” 90 Elbow
  • 3x) 12v Brushed DC Motors
  • 3x) propellers with shafts
  • 3x) Empty Film Canisters With Lids
  • 3x) 22 AWG 20” insulated wires
  • 3x) Momentary DPDT switches
  • 3x) ½” “T” Fitting
  • 8x) ½” 3-way PVC Fitting
  • 9x) ½” #6 wood screws

Step 2: Tools

The tools required for this project are:

  • Pvc cutter
  • Tape measure
  • Soldering iron
  • Band saw/Hacksaw
  • Drill press and or hand drill
  • Drill bits (size TBA)
  • Permanent marker
  • Wire cutters
  • Wire strippers
  • Utility knife

Step 3: What You Need to Build the Frame

Cut list:

  • 4x) 14” ½” PVC Pipes
  • 4x) 2.5” ½” PVC Pipes
  • 6x) 6” ½” PVC Pipes

Materials Needed:

  • 1x) ½”x10’ PVC Pipe
  • 2x) ½” “T” Fittings
  • 8x) 3-way ½” PVC Fittings


  • PVC Cutters

Step 4: Building the Frame Step 1

Gather all of the 14” pipes and on each pipe end attach a 3-way fitting. Ensure the fittings are aligned the same way.(see image)

Step 5: Building the Frame Step 2

Take two of the parts you just made and attach them together using two 6” pipes. Repeat with the remaining two parts. Now you should have two rectangles, each should have 4 openings from the 3-way fitting all facing up.

Step 6: Building the Frame Part 3

Take the two "T" fittings and insert two 2.5" pipes into each wing end.

Step 7: Building the Frame Part 4

Insert the two pieces with the "T" fittings on one side (short end) and insert the remaining two 6" pipes in the opposite side. Attach the other rectangle on top to form a box shape.

Step 8: What You Need for the Motor Assembly


  • Small DC brushed motor (ensure its small enough to fit inside of the film canister)
  • Tape
  • Empty film canister
  • Wax toilet bowl seal
  • Cat 5 wire (40'+)
  • Bidirectional propeller (for water)
  • Alcohol cleaning wipes


  • Hand drill
  • Soldering iron
  • Sand Paper
  • Power Supply

Step 9: Building the Motor Assembly

Roughly measure the motor shaft and the wire you're using then drill the appropriately sized hole in the bottom of the canister for the shaft and a hole in the lid for the wire. Route two wires through the hole in the lid then tie a knot to reduce strain on the future solder connections. Using the tape, mask off all of the open ports and holes on the motor.

Step 10: Building the Motor Assembly Part 2

Pack a small amount of toilet bowl seal wax into the rear of the canister and insert the motor, shaft first.

Try not to get wax on the shaft as you push the shaft through the drilled hole. Solder two of the wires inside of the cable, preferably the same colors to the motor leads and pack the front with wax before capping the canister. It is best to color code everything for when wiring the switches later.

Step 11: Building the Motor Assembly Part 3

Attach the wires coming out of the motor assembly to a 12v power supply. Using a small piece of sand paper, gently sand the spinning shaft just enough to rough up the shiny metal surface. This will give the shaft more surface area for the super glue to attach to. Disconnect from power and super glue the propeller to the shaft. It is not important which way the propellers or wires are attached as long as they are all made the same way.

Step 12: What You Need to Build the Hook


  • 1x) 1/2" PVC end cap
  • 1x) 1/2" PVC pipe
  • 1x) 1/2" "T"
  • 2x) 1/2" 90 degree elbows
  • 2x) 1/2" 45 degree elbows

Cut List:

  • 1x) 2" 1/2 pvc
  • 1x) 1.5" 1/2 pvc
  • 1x) 3.75" 1/2 pvc
  • 4x) 1" 1/2 pvc

Step 13: Building the Hook Part 1

Insert the 3.75" pipe into one end of a 90 degree elbow and the 2" pipe into the other end. Attach the end cap to the 2" pipe end. Attach the remaining 90 degree elbow to the other end of the 3.75 degree pipe. Insert the 1.5" pipe into this elbow and then the base of the "T" onto this. Insert 2 1" sections into each wing of the "T" See image.

Step 14: Building the Hook Part 2

Take the pipes sticking out of the "T" wings and insert them into the 45 degree elbows at the front of the frame. (See image.)

Step 15: Finishing the Hook

Find a drill bit that will work with your magnets, I would recommend drilling a pilot hole before you go in with your screw however it is completely up to you, whether you do this or not. Once you choose a drill bit measure out where you want your magnets to be placed on the cap of the hook, this is also completely up to you and your sub’s needs. Mark where you want them to go.

Drill away!! If your magnets do not have a hole in the center be careful when drilling. You do not want to risk breaking them. You could super glue them instead.

Step 16: What You Need to Build the Motor Mounts


  • 1/2" Fence Panel
  • 12x) Small #6 wood screws
  • 4x) Motor assembly

Tools Required:

  • Band saw (hack saw)
  • Drill press and/or hand drill
  • 7/8" forstner bit
  • 1 1/4" forstner bit
  • 5/64" twist bit
  • Bench grinder (or any abrasive)

Step 17: Designing the Mounts

The mounts i made were as slim and round as possible to avoid snagging on things as well as cut down on drag. The mounts are also a concave shape so the motors are actually inside of the frame to protect them and keep the propellers from tangling on debris. Trace the design onto the fence panel. Its much easier and safer before cutting it out to drill the holes. Use the 7/8" forstner bit to drill the holes that the pvc will fit through and a 1 1/4" hole for the motors. Drill a hole using the 5/64" bit in the side of the holes. Using the bench grinder, grind the point off the #6 screw so its flat, then insert the motors into the corresponding holes and secure them by tightening the screws.

Step 18: Mounting the Mounts

Now with the motors and mounts assembled, remove the rear of the frame and slide the mounts onto the pipes. Use a ruler to make sure each side of the mount is equal distance from an end so they're not crooked. Tighten the set screws to secure the mounts to the frame. Replace the rear of the frame.

Step 19: Wiring the Controller


  • Something to use as a controller (we used a small pencil case) (preferably something box like)
  • 3x) Momentary DPDT switches
  • Wire
  • Power supply (12v)


  • Soldering iron
  • Wire cutters/strippers
  • Hand drill

Step 20: Building the Controller

Install the three switches, one for the left motor, one for the right motor, and one for the up/down motor. Wire the switches (Video for wiring the switches) for forward and reverse operation. Using the corresponding drill bits, drill holes just large enough for the power supply wire and Cat 5 cable to enter the controller. Tie a knot in each to prevent strain on the solder joints. Each switch should be wired the same and wire all three power inputs to the switches in parallel to the power supply. Ensure all of the motors spin the correct direction to the switch position. If they have all been wired the same way you will either have the correct direction or the wrong direction for all of the motors. If the motors all spin the wrong direction, simply switch the power supply's positive and negative leads.

Step 21: Trouble Shooting Wiring Issues

(Broken Connections)

Find the broken connection and determine where it should have been. This is easy if it’s only one broken connection because there will obviously be a place where the missing wire should go. If there are two, use your other switches and wires for reference it shouldn’t be too difficult to determine especially because you wired and soldered the other switches! Hold the wire in its place first, you can test it before you solder it back into place, if you’d like.

Now you’re ready to re-solder the wire or wires back into place and fix the broken connection or connections. You should already know how to do this, but if you don’t look back to earlier in this instructable. Make sure your wire is back in place.

Now that you’ve fixed the connection, let’s make sure it works. Plug into your power supply, test your switches, and watch your motors spin!!

Step 22: Materials for Finding Neutral Bouyancy


  • Foam Pipe Insulation
  • Electrical Tape


  • Soldering iron (optional)
  • Hand Drill
  • Scissors
  • Pool Or Bathtub Of Water

Step 23: Finding Neutral Bouyancy

Your submarine should be ready now apart from the flotation. Start by placing the sub in the pool and seeing what happens. It will have most likely floated. Drill 1/4" holes in the bottom of the frame AND the top, but make sure they are in the center. 4-6 holes each will suffice for timely and proper flooding of the frame. Place the sub into your body of water and place sections of foam insulation along the top of the frame until the sub becomes as close to neutral buoyant as possible. Secure the foam sections with the electrical tape, being careful not to block any of the venting holes.

Step 24: Have Fun!

After the sub is built and is neutrally buoyant. It is time to use the sub. This sub design is made to pick up obstacles in a pool. It is fun and easy to drive, and requires no batteries so sub run time is infinite. Thanks for choosing our sub design I hope you enjoy your new sub!!