Make an RC Submarine From RC Car!

Introduction: Make an RC Submarine From RC Car!

Start by collecting the following items:

- hot glue gun and multiple glue sticks
- a hobby knife (aka exacto knife)

- one working electric remote control car
- two lego propellers*
- enough batteries for remote and car
- a sturdy** plastic bottle big enough to fit circuit board and batteris but not bigger
- the bottle's cap
- two or three corks
- electric tape
- duct tape
- a hand full of nails
- two or three feet of wire (I used wire from an old lamp but a smaller gauge (diameter) wire would probably work fine)
- WD-40 and/or automotive grease
- a plastic easter egg (optional)

Once you have collected your supplies you move on to step 1 and begin to take apart your RC car to 'harvest' the parts needed for your sub. You should know that your RC car will most likely be unrepairable after these changes.

*The best are the ones meant for lego boats or subs, though, some lego airplane propellers work... as you see in my own sub. See step 6 for a picture of these lego boat/sub propellers. You can can also buy fancy expensive propellers at any hobby shop.

**The plastic bottle must be sturdy because of the pressure that will be on it when diving deep. The deeper the dive the more the pressure.  If your bottle crushes you run the risk of it leaking and damaging circuitry. It could also loose its buoyancy due to a change in volume causing it to sink out of the range of your remote.  Unless you have a fishing line attached when this happens you could loose your sub. 

Here is a video of the finished product at play:

(We attached a string to it while test driving just to be safe.)

Step 1: RC Car Organ Donation

Step 2: Submarine Hull From a Bottle

Step 3: Power Wire Modifications

Step 4: Sealing the Hull

Step 5: Finish the Hull

Step 6: Propulsion Systems

Step 7: Attaching Struts

Step 8: Connecting Propulsion Systems to the Hull

Just leave the motors open because the mechanics and electrical physics of the motors are not hampered by exposure to fresh water. Try to dry them out after a dive so as to avoid rust as long as possible. I would also avoid saltwater as it contains more ionized particles which could corrode the parts faster.

Step 9: Dive Fins

NOTE: I used plastic taken from the plastic body of the RC car to make these fins and it work very well.  However, you can use any sturdy plastic to make these.

Step 10: Buoyancy in the Back

Step 11: Level and Nearly-Neutral Buoyancy

Step 12: Finishing Touches

At this stage you may want to add a little grease and WD-40 to your motors to help protect them form water damage.

Step 13: How to Dive

Enjoy your new RC Submarine!

Step 14: Additional Dive Designs: 2 Channel "Corkscrew"

An easy alternative to the original dive method is to angle the steering motor so that spinning in circles creates a corkscrew effect allowing the user to control depth more precisely, though in a less traditional style.

I have built and tested this design with great results.

Step 15: Additional Dive Designs: 3 Channel "3D"

If you can find (or buy) a three channel remote with motors than this is the design for you. The only change to the original design is an added channel and motor to control the up and down orientation.

I have yet to build and test this design.

Step 16: Additional Dive Designs: 4 Channel "Catamaran"

I plan to try this 4 channel version as my next project. The concept is simply to build a catamaran style sub with each pontoon based on the original design described on this instructable. The major difference being that the steering motors are used to control depth and up/down orientation. 

One VERY IMPORTANT note is that if you plan to uses two remote control cars to make this version it is necessary that the cars be identical in every mechanical and electrical way except that they must operate on different channels.  There are a number of car combo deals out there that sell two cars of the same type but with different channels so that users can race them. This would be ideal.

I have yet to build and test this design.

3 People Made This Project!


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49 Discussions

Thank you for posting this instructable. After coming across this, I was inspired to build my very own. at first i wanted to to build a clone but then I pushed myself to make one that that has some ideas I thought up. Thank you for inspiring me.

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1 reply

Very nice sub. Going to try this one out as soon as I get the parts.

awesome really cool I'm gonna make it!

hi, may i ask what kind of bottle did you use? Is it 1 litter?

does water interfere with the signal?

Hii Instructables

You Guys make me easy to propose my Girl Friend on water with RC Submarine under low budget

Where is the actuall instructions

OK no problem i will buy a RC Car. by the way i am from India and my parents say it is an waste of money. i study in Mayoor Int School, noida, delhi and in 4th language i have chosen robotics so i want to make it. i gave this design to my friend and told to make it then we will show this to our sir idea will be mine but he will build it

I want to ask something what if i use circuit board of a helicopter an change the motors withe mine + batteries

please i have to give this model to my friend this week

1 reply

That is an interesting idea! The short answer is yes, theoretically. I have never used a helicopter but I have thought I about it.

Things to consider as you build your heli turned sub:

- If the helicopter to be repurposed is one of those $20 to $50 fly indoors mini helicopters then it is probably controlled by IR (Infrared) signals. This means (I am guessing here) that your signal will be significantly weakened in the water especially as visibility in the water goes down.

- Again, if your heli is one of those off the shelf $20 types its system is set up like this: Two motors provide the lift through counter rotating rotors (propellers that spin opposite directions). Turning right or left is achieved through a trick where accelerating one of these rotors and slowing the other causes the heli to pivot. There is an additional smaller motor on the tail that tilts the heli forward or backward (causing it to fly forward or backward.)

If this is the way your heli works then you could conceivably use the two lift motors as dual thrusters on the right and left side of the sub. An interesting side product of this would be that when using your controller you could move forward by increasing thrust and could turn right and left using the spin right/left controls. You will need to test which thruster slows and accelerates with the spin right/left controls and then arrange the thrusters on the correct sides of the sub in order to produce a right turn when making a right turn on the controler and like wise with the left turn.

- The only other bit of advice I have for you is that the wiring in those helicopters is often very fragile so as you do your "organ transplant" take care not to break any wire connections. Also keep in mind that some of those helicopters work using a gyroscope and onboard computers meaning the computer may sense that your sub is "off balance" and correct the problem causing your sub to behave unpredictably.

- At the best there are quite a few design challenges to tackle here but plenty of fun to be had in the process.

Let me know how it goes!

what if i use the circuit board of a rc helicopter and change its motor + batteries

please i want the answer in this week

what if i use the circuit board of a rc helicopter and change its motor + batteries

please i want the answer in this week

What a magnificient idea!! I realy cannot thought this think before. Nice job!