High-Speed Sled Adds Bicycle Suspension

January 19, 2023 by Bryan Cockfield 3 Comments

While you might have bought the best pair of skis in the 90s or 00s, as parts on boots and bindings start to fail and safety standards for ski equipment improve, even the highest-quality skis more than 15 or 20 years old will eventually become unsafe or otherwise obsolete. There are plenty of things that can be done with a pair of old skis, but if you already have a shot ski and an Adirondack chair made of old skis, you can put another pair to use building one of the fastest sleds we’ve ever seen.

[Josh Charles], the creator of this project, took inspiration from his father, who screwed an old pair of skis to the bottom of an traditional runner sled when he was a kid. This dramatically increased the speed of the sled, but eliminated its ability to steer. For this build [Josh] built a completely custom frame rather than re-use an existing sled, which allowed him to not only build a more effective steering mechanism for the skis, but also to use bicycle suspension components to give this sled better control at high speeds.

This build is part of a series that [Josh] did a few years ago, and you can find additional videos about it documenting his design process and his initial prototypes and testing. The amount of work he put into this build is evident when it’s seen finally traversing some roads that had been closed for winter; he easily gets the sled up in the 30 mph range several times. If you’re looking to go uphill in the snow, though, take a look at this powered snowboard instead.

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Inputs Of Interest: The Infogrip BAT Chording Keyboard

August 18, 2020 by Kristina Panos 29 Comments

I guess it shouldn’t surprise me that by researching weird and interesting keyboards, I would uncover more weird and interesting keyboards. This is the BAT personal keyboard by Infogrip, and it’s something I came across while researching the DataHand keyboard and mentally filed away as something cool to look into.

When I came across a used BAT for a reasonable price, I snagged it, even though it didn’t come with any of the manuals or software, not even a cord. Like I said, reasonable price. I looked these keyboards up and found out that you can buy them new for a lot more than what I paid.

My gently used BAT in all its angular glory.

The lowercase letter chords use either the middle thumb key or no thumb key. Image via Infogrip

So what is this thing? It’s a chording keyboard that’s meant to be used a standard PC input device by anyone who either can’t use a regular keyboard or has a need for speed. Years of research went into the BAT’s chording scheme, which was developed in conjunction with NASA’s Stennis Space Center.

Instead of stretching your fingers all over a regular keyboard, poking keys one at a time to spell out words, you press combinations of keys simultaneously, like playing chords on a piano.

You’re meant to use your thumb for the red, grey, and blue keys, and lay the other four on the rest of the keys. All of the alphabet keys are chorded with or without the gray thumb key, and all the number, symbol, and modifier keys are accessed through the red and blue layers.

Why would you want one of these? Well, given enough time to learn the chords, you can do anything a standard 104+ keyboard can do with only seven keys. You would never need to look down, not even for those weird seldom-used keys, and the only finger that ever travels is your thumb. All of this reduced hand/finger/wrist travel is going to be easier on the body.

The BAT lets you CAD like a madlad. Via Bill Buxton

The BAT is also part programmable macro pad, and from what I can gather, the main selling point was that you could quickly input shortcuts in CAD programs and the like, because you could keep one hand on the mouse.

The BAT came in both left- and right-handed versions that can be used either alone or together. Imagine how fast you could type if you chorded everything and split the typing duties between both hands! The only trouble is learning all those different finger combinations, although they say it doesn’t take that long.

So why is it called the BAT? Legend has it that it’s because company started out in Baton Rouge, Louisiana, but also because a pair of BATs sitting next to each other resembles a bat (PDF).

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Retrotechtacular: Automotive Suspension Is All About Waves

March 11, 2020 by Mike Szczys 30 Comments

In addition to driving home the need for Steadicam or Optical Image Stabilization, this eighty-year-old video illustrates some elegant solutions the automotive industry developed in their suspension systems. Specifically, this Chevrolet video from 1938 is aimed at an audience that values science and therefore the reel boils down the problem at hand using models that will remind you of physics class.

Model of a wheel with a leaf spring records the effect of a bump on a piece of paper above

The problem is uneven ground — the “waves in the Earth’s surface” — be it the terrain in an open field, a dirt road, or even a paved parkway. Any vehicle traveling those surfaces will face the challenge of not only cushioning for rough terrain, but accounting for the way a suspension system itself reacts to avoid oscillation and other negative effects. In the video this is boiled down to a 2-dimensional waveform drawn by a model which begins with a single tire and evolves to include a four wheeled vehicle with different suspension systems in the front and the rear.

Perhaps the most illuminating part of the video is the explanation of how the car’s front suspension actually works. The wheels need to be able to steer the vehicle, while the suspension must also allow the tire to remain perpendicular to the roadway. This is shown in the image at the top of this article. Each wheel has a swing arm that allows for steering and for vertical movement of the wheel. A coil spring is used in place of the leaf springs shown in the initial model.

You probably know what’s coming next. The springs are capable of storing and releasing energy, and left to their own devices, they’ll dissipate the energy of a bump by oscillating. This is exactly what we don’t want. The solution is to add shock absorbers which limit how the springs perform. The waveforms drawn by the model encountering bumps are now tightly constrained to the baseline of flat ground.

This is the type of advertising we can wholeheartedly get behind. Product engineers of the world, please try to convince your marketing colleagues to show us the insides, tell us why the choices were made, and share the testing that helps users understand both how the thing works and why it was built that way. The last eighty years have brought myriad layers of complexity to most of the products that surround us, but human nature hasn’t changed; people are still quite curious to see the scientific principles in action all around us.

Make sure you don’t bomb out of the video before the very end. A true bit of showmanship, the desktop model of a car is recreated in a full-sized Chevy, complete with “sky-writing smoke” to draw the line. I don’t think it’s a true analog, but it’s certainly the kind of kitsch I always look for in a great Retrotechtacular subject.

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