The team over at [Braille Skateboarding] is willing to ride just about anything. This week they’re testing out 3D printed skateboard wheels. We’re not just talking rolling around here, the [Braille] team takes their experiments out to the skate park and gives them to the locals to test out. Tail whips, jumps, ollies, and grinds were on the agenda. The skaters were a bit apprehensive, as this is the third time they’ve tested 3D printed wheels.
The first set shattered upon landing a jump. That set appears to have been made from PLA with about 10% infill. The second set were made from NinjaFlex, which had no shattering problems, but was so squishy that the wheels simply flattened under the weight of the riders. The third set, printed by [Nick Lindenmuth] work great. They have a bit of give, but don’t shatter. We’re guessing this set is either ABS or one of the more exotic filaments. It’s pretty amazing that 3D printers are capable of spitting out wheels that not only handle the load of rider, but the shock load of coming down from jumps and tricks.
Check out the video after the break. If you want to see more skateboard projects, check out this skateboarding themed Hacklet!
Continue reading “Skateboard Hackers Trick on 3D Printed Wheels”
Skateboarding is a sport that was born of hacking. The identity of the person who first nailed roller skate wheels to a board with a milk crate box is lost to history. Those crate scooters were a staple of the 1940’s and 1950’s neighborhoods. Everyone built their own scooter, so the designs evolved. Eventually the milk crates disappeared. At some point, surfers realized that they could use these wheeled boards to surf the concrete jungle. Things just took off from there. Skateboarding is now a multi-billion dollar industry, but at its heart there are still hackers trying out new designs. This week’s Hacklet is all about skateboarding projects.
We start with [brian.rundle] and Electric Longboard. [Brian] built his board using trucks and mechanical parts from a DIY skateboard online shop. The motor is a brushless outrunner R/C plane motor from HobbyKing. Batteries are of the LiPo variety. An Arduino Nano provides the PWM signal which drives the Electronic Speed Control (ESC). Throttle control is via RF link using the popular Nordic Semi NRF2401. [Brian] is focusing on building a safe skateboard. He designed it to carry two batteries, though only one is in use at a time. Rather than use a switch, he’s created a fool-proof system with arming plugs and jumpers. Each battery has its own arming plug. There is one jumper, so only one battery can be connected to the board at a time.
Next up is [suiram21] with Longboard Brake. Downhill longboarding can be a dangerous sport. Running downhill at 40MPH or more with no brakes makes for quite an adrenaline rush. [suiram21] loves longboarding but wanted the safety of having a brake if and when he needed it. He started with a Onda board, which is a longboard with large diameter wheels. He 3D printed brackets for a cable actuated braking system. The brake is activated by stepping on a lever at the rear of the board. A lever presses a bicycle brake pad into the inside edge of the tire. This brings the board to a gentle stop. [suiram21] is thinking of adding a second brake to the other wheel to increase braking authority.
Next we have [edbraun] with Skateboard Speedometer by inventED. [edbraun] wanted to know how fast he was going. A GPS would work, but GPS signals are often blocked in cities. A more accurate way to gather speed data is directly from the wheels. Two tiny magnet plugs are placed in holes drilled in the wheel. A hall effect sensor detects the magnets and passes this data on to an Arduino Pro Mini. Once the speed is calculated, it’s sent to a Bluetooth radio. [edbraun’s] Android phone receives the data and displays current speed and total distance traveled. The speedometer and its slick 3D printed case almost hide between the trucks and the board itself. Nice work [edbraun]!
Finally we have Hackaday alum [Josh Marsh] and EV Commuter Longboard. [Josh] uses an electric longboard for his daily commute. His project is an excellent overview and tutorial on building an electric skateboard from scratch. Like many others, [Josh] utilizes R/C Airplane brushless motors and speed controllers. An Arduino or similar microcontroller is all you need to drive these devices. For batteries, [Josh] loves LiPo packs. Long form six cell affairs provide 22.2 Volts with a capacity of 5000 mAh or more. Plenty of power for carving your way to work!
If you want to see more skateboard projects, check out our new skateboard projects list! If I missed your project, don’t be shy, just drop me a message on Hackaday.io. That’s it for this week’s Hacklet. As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!
There’s a gritty feel to the Hackerboat project. It doesn’t have slick and polished marketing, people lined up with bags of money to get in on the ground floor, or a flashy name (which I’ll get to in a bit). What it does have is a dedicated team of hackers who are building prototypes to solve some really big challenges. Operating on the ocean is tough on equipment, especially so with electronics. Time and tenacity has carried this team and their project far.
Continue reading “Building a Swarm of Autonomous Ocean Boats”
I could have sworn that we have asked this one before, but perhaps I’m thinking of our discussion of nuclear aircraft. In my mind the two share a similar fate: it just isn’t going to happen. But, that doesn’t mean flying cars can’t happen. Let me make my case, and then we want to know what you think.
[Steve] sent in a link to a Bloomberg article on Larry Page’s suspected investment in personal flying cars. It’s exciting to hear about test flights from a startup called Zee.Aero with 150 people on staff and a seemingly unlimited budget to develop such a fantastic toy. Surely
Bruce Wayne Mr. Page is onto something and tiny 2-person vehicles will be whizzing up and down the airspace above your street at any moment now? Realistically though, I don’t believe it. They definitely will build a small fleet of such vehicles and they will work. But you, my friend, will never own one.
Continue reading “Ask Hackaday: Where are the Flying Cars?”
[XenonJohn] wrote in to let us know about updates and a recent test drive of an Electric Self-Balancing One-wheeled Motorcycle, fresh from the beach where he says it proved to be great fun to ride. The design and build have been updated since we last saw it as a semifinalist entry in the 2014 Hackaday Prize. The original, he says, “looked cool but was slow, cumbersome and really dangerous to ride.”
Since then it has been completely redesigned and now has a super fat kite-surfer wheel, a front crash skid with damper, and a variable geometry which allows it to steer properly despite just having one wheel. It does this by allowing the rider to shift their position relative to the wheel, instead of the seat always being rigidly locked directly above the axle.
That steering is a pretty clever upgrade, but we do wonder if the new crash skid will have an atlatl effect and really launch the rider in a crash. Our gut feeling aside, it is designed not to plant itself in the pavement, but to slide along (without ejecting the rider) until the vehicle loses all momentum.
There is something about self-balancing unicycles that attracts experimenters, each of whom takes a different approach. We see everything from this device constructed mainly from a Razor Scooter to this more polished-looking unit based on an earlier Segway clone design. [XenonJohn] reminds us that “there is still much to learn in this area and you can genuinely innovate even as a hobbyist. Also, you can only do so much on a computer, you then have to actually build something and see how well it works. [This recent test] shows what you can do if you just keep on experimenting.” Video of the test drive is below.
Continue reading “Self-Balancing One-Wheel Motorcycle Tears Up the Beach”
If you ever encounter railroad or railway enthusiasts, you may have heard the view that at some point in the past there was a golden age of rail transport that has somehow been lost. It’s something that’s up for debate as to when that age was or even whether with a selection of new super-high-speed trains snaking across our continents we’re in a golden age now, but it’s true to say that the rail business has had its fair share of decline in the last half-century.
It’s quite likely that when they talk of a golden age, they really mean a golden age of steam rail transport. At which point depending on where you live in the world it’s easier to put your finger on a decade. For UK residents a good candidate would be the 1930s; steam locomotive design had reached its peak, the rail network hadn’t been worn out by the demands of wartime, and private car ownership hadn’t eaten into their passenger numbers. The country was divided up into a set of regional rail monopolies, each of which had their own locomotive works and designers who were in fierce competition to show that their machines were the best and the fastest.
The LMS, the London Midland and Scottish railway company, served the northwestern segment of the country, North Wales, and the West of Scotland. Their high-speed express trains were in hot competition with those of the LNER, the London and North Eastern Railway, who served the eastern side of the country, to offer the fastest service from London to Scotland. It’s difficult to grasp through an 80-year lens, but this battle was one of national excitement, with the fastest locomotives becoming household names nationwide. The railway companies were justifiably proud of their engineering expertise, and so featured their locomotives as a key part of their marketing to the general public.
And so we come to the subject of today’s Retrotechtacular piece, a film below the break from 1935 following the construction of a high-speed express locomotive from start to finish in the LMS’s Crewe railway works. 6207 was one of a class of thirteen 4-6-2 Pacific locomotives designed by the company’s chief engineer [William Stanier], built between 1932 and 1935 and known as the Princess Royal class, all being named for princesses. In the film we see the various parts of the locomotive being cut, cast and forged from raw metal before being assembled in the Crewe plant. All the machinery is human controlled, and one of the surprises is sometimes the number of people involved in each task. The level of skill and experience in precision metalworking to be found in plants like Crewe was immense, and in some cases it is very difficult to find its equivalent in our own time.
Continue reading “Retrotechtacular: 6207, A Study In Steel”
Human ancestors have been walking around on two legs for a few million years. We’d imagine that by now we’ve figured out a pretty efficient mechanism for getting around. Unconvinced, however, researchers at Carnegie Mellon University have developed an “exo”-boot that reduces the metabolic rate of walking by seven percent. Best of all, the mechanism requires no additional source of active power input besides the human legs that are wearing them.
Upon close inspection, the boots reduce the overall applied torque at the angle joint at a critical point where the heel begins to lift off the ground. Energy in, energy out. The spring ratchets to a loaded position as the user plants their foot. This ratchet releases, re-engaging the stored spring force as the user brings their heel back off the ground. A seven percent reduction in metabolic rate may not sound like much, but, according to the paper, it’s the equivalent of about four kilograms less weight in your backpack on that next hiking trip.
As for what specific costs are being reduced to lower the body’s metabolic rate, the researchers still aren’t completely sure. An off-the-cuff look at the joints and moments from a mechanics perspective won’t give us a sure-fire answer since the energy consumption processes of muscles are, well, complicated. In fact, by varying spring stiffness in their design, they discovered that springs that were either too stiff or too loose had no effect on the metabolic rate. Yes, they’ve certainly stumbled on a sweet spot in terms of well-mixed circumstances, but the answer behind why the new robot-legs work so smoothly will be a study for the future.
If you haven’t jumped into the world of exo-skeleton building, let [James Hobson] be your guide into pushing our bounds with homebrew mechanical advantages. Now let’s keep our fingers crossed for some long-fall boots.
via [The Washington Post]