Eight Motors Speed This Boat Along

December 21, 2019 by Jenny List 16 Comments

Messing about in boats has always held a curious appeal for the hardware hacker. Perhaps that’s because it remains an approachable way to make something that moves under its own power with a bit of speed, and barring calamities, the worst that can happen to the unwary boater is a soaking. [NASAT Channel] is a Vietnamese hacker who is a serial producer of small motorised boats, and one of his latest is a particularly impressive example.

The boat itself is a relatively conventional expanded polystyrene hull covered with fiberglass, but the motive power is something a little special. He’s taken eight of the ubiquitous 775 DC brushed motors and used them in a star configuration with beveled gears, which in turn drives a flexible shaft which goes straight to a propeller under the craft. Each motor shares a water cooling pipe serviced by a small pump, and the drive comes from a pair of cheap PWM motor controllers. We see him zipping up and down a stretch of river next to some moored boats, and if we’re honest, we wouldn’t mind a go ourselves.

We’re not entirely convinced such a rough-and-ready eight-way gearbox will be reliable for long-term use, and we’d be interested to know just how equally so many motors are actually sharing the load. But we like it for its sheer audacity, and we think you will too. Take a look at the video below the break, and if you’re inspired then grab a hammock, some friends, and have a go.

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Is It A Boat? Is It A Hammock? No, It’s Both!

September 13, 2019 by Jenny List 15 Comments

If you’re enjoying a Western Canadian summer, two of the best ways to do so involve a hammock, or a boat. Seeking to improve on this mighty duo with a hammock-boat combo, [Jarrett] describes his progress at Vancouver Hack Space.

The boat he chose was a one-person catamaran with an aluminium frame and what appear to be inflatable pontoons, while the hammock is one designed for a garden or patio with a steel tubular frame. A design goal was to not modify or destroy the structure of either item, so the challenge was to securely mount the two frames together. A variety of false starts involving bent steel or aluminium were tried, followed by a final success with the aluminium tubes reinforced with more tube inside them, and the hammock attached with U-bolts.

The testing took place on what appears to be a public lake, and the contraption floated well. When it had been pushed out to a landing stage our intrepid adventurer boarded the hammock — and promptly the whole edifice tipped itself over, depositing him in the drink. Further experimentation revealed that balance was critical, and a revised position could achieve a stable boarding. He paddles off into the sunset as you can see in the video below the break, though as his friends remind him, without his beer.

Commercial hammocks are surprisingly expensive for what they are. Don’t worry though, if you find them to be beyond your budget you can always make a frame for one yourself.

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ArduRover Boat Uses Tub To Float

August 18, 2019 by Ben James 16 Comments

There’s nothing quite like the sight of a plastic box merrily sailing its way around a lake to symbolise how easy it is to get started in autonomous robotics. This isn’t a project we’re writing about because of technical excellence, but purely because watching an autonomous plastic box navigate a lake by itself is surprisingly compelling viewing. The reason that [rctestflight] built the vessel was to test out the capabilities of ArduRover. ArduRover is, of course, a flavour of the extremely popular open source ArduPilot, and in this case is running on a Pixhawk.

The hardware itself is deliberately as simple as possible: two small motors with RC car ESCs, a GPS, some power management and a telemetry module are all it takes. The telemetry module allows the course/mission to be updated on the fly, as well as sending diagnostic data back home. Initially, this setup performed poorly; low GPS accuracy combined with a high frequency control loop piloting a device with little inertia lead to a very erratic path. But after applying some filtering to the GPS this improved significantly.

Despite the simplicity of the setup, it wasn’t immune to flaws. Seaweed in the prop was a cause of some stressful viewing, not to mention the lack of power required to sail against the wind. After these problems caused the boat to drift off course past a nearby pontoon, public sightings ranged from an illegal police drone to a dog with lights on its head.

If you want to use your autonomous boat for other purposes than scaring the public, we’ve written about vessels that have been used to map the depth of the sea bed, track aircraft, and even cross the Atlantic.

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Building An RC Air Boat From Garbage

April 12, 2019 by Tom Nardi 7 Comments

What do you get when you combine an old optical drive, some empty soda bottles, and a microcontroller? Well…nothing, really. That’s still just a pile of rubbish. But if you add in a battery, an RC receiver, and some motors, you’re getting dangerously close to a fun little toy to kick around the pond as [Antonio Rizzo] recently demonstrated.

A couple of plastic bottles lashed together make up the hull of the boat, and [Antonio] has used the internal frame of an old optical drive bent at a 90 degree angle to hold the two small DC motors. In a particularly nice touch, the drive’s rubber anti-vibration bushings are reused as motor mounts, though he does admit it was just dumb luck that the motors were a perfect fit.

For the electronics, [Antonio] has paired a custom motor controller up with the uChip, a diminutive Arduino-compatible microcontroller in a narrow DIP-16 package. Wireless communication is provided by an off-the-shelf cPPM receiver such as you might see used in a small plane or quadcopter.

The whole build is powered by a common 18650 lithium-ion battery, which could also be easy enough to recover from the trash given how common they are in laptop batteries; though if you threw a new cell into this build we wouldn’t hold it against you. Everything is put into a high-tech plastic sandwich bag to provide minimum of waterproofing with the minimum of effort.

If using a commercial RC receiver and transmitter is a bit too mainstream for your tastes, you could always roll your own radio.

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Electrifying A Vintage Outboard Motor

January 10, 2019 by Tom Nardi 14 Comments

Clamped or bolted to the stern of the boat, outboard motors offer a very easy and (relatively) economical way of powering small craft. The vast majority of these outboards are gasoline powered, with electric models generally limited to so-called “trolling motors” which are often used to move slowly and quietly during fishing. That might be fine for most people, but not [Olly Epsom].

An engineer focusing on renewable energy by profession, [Olly] wanted to equip his small inflatable dinghy with a suitably powerful “green” propulsion system. Deciding nothing on the market quite met his requirements, especially for what manufacturers were charging, he decided to convert an old gas outboard to electric. Not only did he manage to do it for less money than a turn-key system would have cost, but he ended up with a system specifically geared to his exact requirements. Something he says will come in handy if he ever gets around to converting the dinghy to remote control so he can use it as a wildlife photography platform.

Put simply, an outboard motor consists of a gasoline engine with a vertical shaft that’s coupled to a right-angle gearbox with a propeller on the end. Beyond that they’re a fairly “dumb” piece of gear, so replacing the engine on top with something else should be (at least in theory) a pretty simple job. Especially on the small older model that [Olly] decided to use as a donor unit. The 1974 Johnson 2 HP motor didn’t have any tricky electronics in it to contend with; the thing didn’t even have a clutch.

Once [Olly] had removed the old gas engine from the top of the outboard, he designed an adapter plate in OnShape and had it cut out of aluminum so he could mount a beefy 1 kW 48 V brushless electric motor in its place. Connecting the new electric motor to the carcass of the outboard actually ended up being simpler than putting the original motor on, as this time around he didn’t need to reconnect the cooling pumps which would usually pull water from down by the propeller and recirculate it through the engine.

While the mechanical aspects of this project are certainly cool, we’re especially interested in the control system for this newly electric outboard. It uses a 3.2 inch Nextion color touch screen and Arduino Nano to provide a very slick looking digital “dashboard” which can convey motor status and other information at a glance. Unfortunately, [Olly] says the details on that part of the project will be saved for a future post, leaving us with only a single picture of the system’s interface for us to drool over until then.

We’ve seen the occasional seafaring project that made use of an electric trolling motor, and we’ve even seen an electric drill put in some overtime spinning a prop in the water. Converting gasoline boat over to electric is however a rarity. But much like electric car conversions, such projects may become more common as the cost and complexity of powerful electric propulsion systems continues to fall.

[Thanks to Alex for the tip.]

Spend All Day On The Lake

December 6, 2018 by Bryan Cockfield 23 Comments

Solar vehicles are getting more and more common as the price of solar panels comes down, and the availability of motors and controllers for all of these vehicles rises. Making a solar-electric bike from a kit is one thing, but this solar-powered boat is a master class in hacking at all levels, from the solar drive train to the pontoons, and even the anchor.

[J Mantzel] has many videos about his boat on his channel, and watching them all will likely leave you wanting to build your own. He builds almost everything on his boat from scratch from things he has lying around. For example, the anchor was hand-built from fiberglass and then filled with concrete, and his steering system is a semi-complex system of ropes, pulleys, and shafts. Most of the boat’s shell was hand-built from fiberglass as well, and everything that can be repurposed is saved for later use.

The ten panels, batteries, inverter, and other miscellaneous part of the system were about half of the cost of the whole vessel, but he reports that he also uses the boat as a backup power source for his house, and can use the system to run other things like an electric chainsaw for example. He also uses the boat for camping and construction, and without having to worry about fuel it has been very useful to him.

If you get into the videos on the channel, you’ll find that this isn’t his only solar-powered boat. He recently completed a solar speedboat as well with a custom-built propeller that can really move across the water. His videos are apparently very popular as well, since they have been linked to repeatedly by readers in some of the recent solar vehicle write-ups we’ve published.

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Go Up A Creek Without A Paddle

December 4, 2018 by Bryan Cockfield 31 Comments

Kayaks are a some of the most versatile watercraft around. You can fish from them, go on backpacking trips, or just cruise around your local lake for a few hours. They’re inexpensive, lightweight, don’t require fuel, and typically don’t require a license or insurance to operate. They also make a great platform for a solar-powered boat like this one with only 150 watts of panels and a custom-built motor with parts from an RC airplane.

[William Frasier] built his solar-powered kayak using three solar panels, two mounted across the bow of the boat using pontoons to keep them from dipping into the water, and the other mounted aft. Separating the panels like this helps to prevent all three of them being shaded at once when passing under bridges. They’re all wired in parallel to a 12V custom-built motor which is an accomplishment in itself. It uses custom-turned parts from teak, a rot-resistant wood, is housed in an aluminum enclosure, and uses an RC airplane propeller for propulsion.

Without using the paddles and under full sun, the kayak can propel itself at about 4 knots (7 kmh) which is comparable to a kayak being propelled by a human with a paddle. With a battery, some of the shading problems could be eliminated, and adding an autopilot to it would make it almost 100% autonomous.

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