The Self-Balancing Sideways Segway

August 1, 2015 by James Hobson 13 Comments

[Jason Dorie] has been hard at work on his two-wheeled, self-balancing skateboard. He calls it the Sideway.

Similar to the Segway, it relies on the user shifting their weight to control the speed at which it will run. A Wii Nunchuk controller is used to steer, which varies each wheels output, which allows for some tight maneuvering!

Under the deck is a pair of 24V 280W (about 1/3HP each) scooter motors which are driven by two 32A Sabertooth speed controllers. They’re run off a pair of 3 cell 5Ah LiPos which get him about 40 minutes of use — not too shabby! To handle the control algorithm for the IMU, he’s using a Parallax Propeller with custom software.

To demonstrate, he takes us of a tour of one of his favorite stores — Michael’s.

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Trying To Set Things On Fire, You Know…for Science.

July 25, 2015 by George Graves 26 Comments

This video from [Just Think] caught our attention for open-flame testing of 6 different commonly used liquid fuels: Jet-A, diesel, heating oil, kerosene, avgas (100LL), and gasoline (or petrol, for our international readers). We love his low-tech approach to testing – just some mason jars and a back yard. The results are quite interesting.

He starts with testing Jet-A fuel. Yep, the same stuff you’d fill up your Boeing 737 with. We flinched for a second as he drops a match into it – then nothing happened. It’s a common misconception that jet fuel will sustain a flame by its self. It needs to be atomized to burn, as he shows in the video. He moves on to test both diesel and heating oil – making note that both are exactly same, except for color. Heating oil has a red dye added to it, to mark it “not for sale” for cars and trucks, as it’s not taxed. Neither would keep a flame.

Next up is kerosene, and it would just barely keep a flame. kerosene is commonly used as a replacement for diesel in extremely cold climates, were diesel fuel would gel and clog fuel systems. Finally, he tests avgas and gasoline. Both would sustain a flame quite well.

We think this small experiment is interesting, in that the results are kind of counter-intuitive. All these different fuels are used in different applications because of their different properties, and of course there is some really interesting science behind that, if you want to learn more.

We don’t need to tell you to be safe when working with fuels. Even though something like Jet-A fuel won’t carry a flame in a container on its own, doesn’t mean that it won’t burn aggressively when combined with other things (like clothing) and in other situations. So we’re filing this one under “don’t try this at home” – instead, sit back and enjoy the YouTube video after the break.

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A Bridge Made Of Aircraft Carriers Will Make [William Gibson] Proud

July 18, 2015 by George Graves 70 Comments

If you’ve ever visited the Puget Sound (the area in and around Seattle, Washington) one thing becomes clear very quickly; It’s not easy to get around when there’s water everywhere. Perhaps that’s why Washington State operates the largest ferry system in all of the U.S., carrying about 23 million passengers each year. It’s not uncommon here to drive (or walk) onto a ferry for a nice boat ride before getting to wherever you need to be.

Another thing the Puget Sound has is naval ship yards. The U.S. Navy has a strong presence here. It’s where many submarines and aircraft carriers come for regular maintenance, as well as decommissioned ships that are stripped of their top secrets parts and nuclear bits. At any given time there can be four or five “slightly used, previously owned” massive aircraft carriers that are that are considered to be in the “reserve fleet” (that is, they can be brought back into service in the case of war.) But usually after a few years pass, and a new carriers are built, the Pentagon will send the floating air field to be dismantled.

Well, someone put two and two together and came up with the idea to use them as a floating bridge – and it’s an interesting hack indeed. Currently the State of Washington is studying the idea, but hasn’t made any firm plans just yet. They have their eye set on a span of water that would need 2-3 aircraft carriers to cover, and that is near the Puget Sound Naval Shipyard. The massive size and over hangs of the ships will still allow for tidal moment, and for local sail boats and pleasure craft to pass between. The hope is that it will be both a traffic solution, and a tourist attraction; not to mention preserving 50 year old ships, that are in many cases, are part of naval history.

We’re not sure if such an idea is practical or not, but our inner Top Gun “Maverick” would love to see such a hack pulled off. And it’s really hard not to make the association with some of the locales imagined in [William Gibson’s] epic work. Will we see the should-be-science-fiction bridge become real? Ooooh how we hope so!

[via dailymail.co.uk]

Nixie Tube Speedometer In Motorcycle Handlebars

July 16, 2015 by Mike Szczys 48 Comments

The handlebars of this Honda CL175 ended up being perfect for holding two Nixie tubes which serve as the speedometer. There are two circular cavities on the front fork tree which are the same size as the Nixies. Wrapping the tubes in a bit of rubber before the installation has them looking like they are factory installed!

This isn’t a retrofit, he’s added the entire system himself. It starts with a hall effect sensor and magnets on the rear wheel and swing arm. Right now the result is 4 MPH resolution but he plans to add more magnets to improve upon that. For now, the driver and speedometer circuitry are hosted on protoboard but we found a reddit thread where [Johnathan] talks about creating a more compact PCB. If your own bike lacks the fork tree openings for this (or you need help with the drivers) check out this other Nixie build for a slick-looking enclosure idea.

The link at the top is a garage demo, but last night he also uploaded a rolling test to show the speedometer in action. Check out both videos after the break.

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Long Board Takes A Brake

July 16, 2015 by James Hobson 20 Comments

Long boards are awesome. They feel like your surfing on concrete — amazing for hilly areas where you can coast around forever. The weird thing is, none of them come with brakes standard… Even though when you’re going down a hill you can easily hit 30-40mph! [Marius] decided to fix this, so he built his own 3D printed brake system for his Onda long board.

He designed the system in 3Ds Max and 3D printed the parts in PLA using his Printrbot Metal Simple (check out our review here). It uses an off the shelf bicycle brake pad, and brake cable as well as a few elastic bands. Currently only one wheel brakes, but it seems to be enough to slow you down — though he might mirror the system on the other side to obtain more braking power.

The long board he’s using does have slightly larger wheels than normal, but the system could be modified to use on a more standard sized long board. Stick around after the break to see it in action.

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Drill Powered Scooter Walks With Legs

July 10, 2015 by James Hobson 35 Comments

[Izzy Swan] is a popular wood working YouTuber who recently fell in love with [Theo Jansen’s] kinetic art — the Strandbeest. Naturally, he had to make his own; but with his own flare of course.

If’ you’re not familiar, [Theo Jansen’s] Strandbeest is a walking kinetic sculpture, powered by wind. It’s inspired a Hamster Ball powered Strandbeest, some nice 3D printed ones, and even a paper craft version! Mechanically, it’s quite a marvel — his TED talk about them is fantastic.

When [Izzy] saw all those legs moving, he knew he had to recreate it — so he came up with this two legged version that pushes him around — kind of like a tricycle, but the back wheels are… legs? It’s an oddity for sure, but an impressive feat nonetheless. Not to mention he’s powering the whole thing using a little cordless drill…

Despite it looking like machined aluminum, it is in fact made of wood, though it does feature a metal gearbox using worm gears to transfer torque from the drill. We want to see a Segway version of this… we might have to make use of the laser cutter in the office…

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Retrotechtacular: The Omega Navigational System

July 8, 2015 by Kristina Panos 7 Comments

In 1971, the United States Navy launched the Omega navigational system for submarines and surface ships. The system used radio frequencies and phase difference calculations to determine global position. A network of eight (VLF) transmitter sites spread around the globe made up the system, which required the cooperation of six other nations.

Omega’s fix accuracy was somewhere between one and two nautical miles. Her eight transmitter stations were positioned around the Earth such that any single point on the planet could receive a usable signal from at least five stations. All of the transmitters were synchronized to a Cesium clock and emitted signals on a time-shared schedule.

A ship’s receiving equipment performed navigation by comparing the phase difference between detected signals. This calculation was based around “lanes” that served to divvy up the distance between stations into equal divisions. A grid of these lanes formed by eight stations’ worth of overlapping signals provides intersecting lines of position (LOP) that give the sailor his fix.

In order for the lane numbers to have meaning, the sailor has to dial in his starting lane number in port based on the maps. He would then select the pair of stations nearest him, which were designated with the letters A to H. He would consult the skywave correction tables and make small adjustments for atmospheric conditions and other variances. Finally, he would set his lane number manually and set sail.

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