Anything can be a remote controlled airplane, and ‘copters – quad or not – simply beat the air into submission. Remote controlled cars are easy, and RC tanks can even shoot their guns. One type of vehicle has eluded remote control hobbyists to a large extent; building a remote control submarine is hard. Not only do you have buoyancy to worry about, but you also need a way to keep the dry parts dry, all while operating in an environment where radio doesn’t really work well.
[Ivan] has already built RC planes, but wanted to tackle a new challenge. He built an RC submarine, and he did it using the simplest household materials.
There are three main challenges to building a submarine. These are the radio system, building a watertight enclosure, and having some sort of ballast tank to pump water into and out of. For the radio system, the now ubiquitous 2.4 GHz radios do not function underwater. Those older radios operating on 27, 40, or 72 MHz do, and after someone heard of [Ivan]’s submarine project, a few junk drawers were scavenged netting a radio system for this sub.
Watertightness was accomplished with a 75mm diameter piece of PVC pipe, capped with plugs and o-rings at both ends. We read on the Internet that using PVC pipe as a pressure vessel has been responsible for more deaths than millennia of plague and war; in this case, it almost works – instead of inevitably exploding, the PVC sub is only in danger of imploding when placed in a bathtub. That’s a completely different failure mode that should allay the fears of even the most vocal critics.
Being able to go underwater doesn’t mean anything unless you can dive and surface again. To do this, [Ivan]’s submarine is using a large syringe attached to a peristaltic pump. To dive, [Ivan] commands the sub to pump water into the syringe. To surface again, the sub pumps water out of the syringe.
On [Ivan]’s blog, you can find links to all the items used in the construction, a few more pics, and a video, also found below.