Make an RC Submarine from RC Car!

Start by collecting the following items:

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

Materials
- 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

Comments

[neodymium]

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

[james03x]

Wow, you are a genius. You did it really wonderfully, i will try to get materiel and start this project very soon. Thanks
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radiografisch auto

[metalhead8711]

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.

[jjapitan]

will trying this on seawater somewhat do damage on the motors??/

[ScrapSmith]

I have never tried it out in salt water but my guess is yes. Technically exposure to any type of water will eventually cause rust and corrosion to your motors but especially salt water. One of the major drawbacks of my design is that it will eventually succumb to water damage. I traded longevity for simplicity. :-)

Your best defense against this is to put a water displacement chemical like grease or better yet WD-40 (stands for Water Displacement formula 40!), or both, in your motors and then dry it out as best you can after each use.

[he who crashes often]

gonna do the same thing, but with a 200-watt brushless motor, and an actual rudder moved by a servo =D

[ScrapSmith]

Sounds awesome! If you send me a picture or video of it we can start a hall of fame at the end of the instructable.

[he who crashes often]

will do. just have to get my old 72mhz radio system working (2.4ghz does NOT like water)

[Instructable Maker]

Overall, it is a very nice design. However, I was wondering if you have any ideas on how to make the diving and movement independent. The current design binds the diving and movement controls together so you can't dive without going forward or go forward without diving. Would it be possible to fit a small water pump inside the hull. It would pump water in and out of a separate compartment (like a ballast tank). This could be a solution but I am not sure if a water pump like this could be powered by simple batteries. What do you think?

[ScrapSmith]

Hey Maker, thanks for the thumbs up! I have been pondering the same questions for some time now and have a few ideas you could try out. Check out the last three steps I just added on Alternative Dive Designs.

In the past I scratch built sub with a balast tank and while it did work I was frustrated to discover it worked more like an on/off switch between floating and sinking. After tinkering around I found that making your sub to be just above neutrally buoyant and then controlling the depth with fins or motors gives much more control and flexibility.

However, if you are still interested in a balast tank I imagine your idea would work well. Another idea I had was to use syringes with a home made actuator to pump water in and out. If you are interested I could make a graphic and add it to the Alternatieve Designs section.

Cheers!

[he who crashes often]

use a real r/c system (can get a transmitter/receiver, servos, motor and speed controller for under $40 at hobbyking.com) and put the dive fins on a pivot hooked up to a servo.

[Instructable Maker]

Oh and by the way, I think that the pictures of the building process are very detailed and well designed. I could see each component and it's orientation in every picture. A very good job :)

[DadhieMJ]

is it ok for the motor to submerge too? or it is needed to seal it too? :)

[ScrapSmith]

Just leave the motors unsealed because the mechanics and electrical physics of the motors are not hampered by exposure to fresh water. I try to dry them out after a dive so as to avoid rust as long as possible. Avoid salt water as it contains more ionized particles which could corrode the parts faster. Enjoy !

[Area A Industries]

Genius!

[Arap Tala]

Great idea. Looks fun and the diagrams help a lot.

[ScrapSmith]

Thanks Capn' and neodymium!
I would love to include any videos of the subs guys you build here on the instructable. That goes for everyone else too!

[captain Jack]

nice graphics