Any chance these will ever get down to ~$300? I guess what I'm asking is if this is the Tesla Roadster and there's an economy model a few generations down the line? Or will this always be for people more serious about using them for commuting, etc?
It's possible to get something like an electric Razor scooter for ~$300, but the parts they use to hit that price, like lead-acid batteries, make it a lot less appealing.
Just like a car or motorcycle, right now there's a floor to how cheap it can be and still be great. If that gets lower over time, all the better.
It looks amazing, but I'm having trouble understanding where the power comes from.
The Kickstarter says 20 mph, 6 mile range, 2000 watts, which gives an energy of 600 watt hours.
A Macbook battery is around 60 watt hours, and weighs about 1.5 pounds; 10 of those would weigh 15 pounds - and take up a ton of space. I don't see the volume of even ONE in any of the photos I've seen.
The battery is just under 100 watt hours. The motor power lets you accelerate uphill, but the range is calculated from riding at a constant speed on flat ground.
I love this post because it shows some real engineering. The fact they put so much effort into the test equipment shows that there's some serious characterization going on vs. just throwing together parts.
I really wouldn't call this "real" engineering. As a mechanical engineer it really sounds like they literally threw it together and hoped it fit after they tested the motors "...models were assembled together in the CAD software to check for fit, clearance, and interference." I saw no mention of fatigue analysis or FEA, both are now days required for "real" mechanical engineering. Without that just cross your fingers the motors don't fall off after 1000 miles. Other than that it is pretty comprehensive.
I really hope the link between the remote and the board is secured properly, it would be a really nasty prank to overpower the transmitter from some vehicle and to cause it to accelerate or come to a sudden stop. Griefers are not limited to being active online.
I think this is still, by far, one of my favorite "last mile" solutions. It's got a pretty slick look, it'll do basically all of the work for me, and I could carry it inside somewhere pretty easily.
Biggest downside I'm wondering about is only being able to use it when it's dry out (not sure there much to be doe about that while staying reasonable).
I'm a fairly avid cyclist, though. I think than between a boosted board and my trusty bike, I'd cover a pretty huge swath of my use cases.
One of the reasons for which motors in scooters and other electric vehicles are large and bulky is that they have to be designed to last a long time in real world environments.
The motors being used for this project are hobby model aircraft motors. These motors put out a lot of power per unit volume but are most definitely not designed for continuous duty at anywhere near to full output. They are also not sealed against the elements and have bearings selected for reasonably balanced loads with relatively low radial loads.
I have piles of these on my workbench ranging from cheap Chinese units to top of the line German designs. I use these on our planes, helicopters, multi-rotors, boats and cars. At the top end you have amazing hand-crafted quality with a prohibitive price (unless you want to pay $8,000 for a skateboard). At the low end they are cheap and they are junk. I've seen everything from magnets coming off, coils burning out, power leads coming off, bearings going bad prematurely and shafts bending.
In short, while the design process is interesting, I think the most fundamental flaw is being ignored: The motors are not designed, nor are they suitable for, this kind of an application.
What are the safety concerns of something like this? A top speed of 20mph will definitely be unstable for general usage, and even 15 seems more like bicycle territory, where you're seated and have an aerodynamic shape.
We might see many people falling off of these in the future...
A longboard turns in the direction you're leaning and so is dynamically stable. In fact (counter)steering is more intuitive than on a bike because you don't have to coordinate lean and handlebar angle.
The main issue with skateboards is 'speed wobble' vibration in the trucks, but a well set-up board generally isn't prone to this.
For more than a year, I commuted to and from work (3 miles each way) on a lightweight electric scooter I bought on Craigslist for $100. It's been a while, but I used to skateboard, surf and snowboard, but having the handlebars of a scooter in an urban environment is huge for me in terms of control and safety. I used to call it the poor-man's Segway.
I think that taking this [1] rather insane idea for a "longboard stroller", and replacing the child(!) with one's laptop bag and maybe some kind of fairing would be a pretty sweet solution for those of us not agile enough for regular longboarding.
The 11% average over 1km isn't too bad, but the start looks pretty steep. Strava shows it at up to 40%. That's not exactly 100% accurate, but I've ridden 25-30% slopes on Strava and they are hard enough that on my road bike I can't stay seated (the front wheel comes off the ground) and if it is the slightest bit wet the rear wheel slips when you stand.
I'd be very impressed if this can make it up there with a person on it.
I'd love to see a mountainboard/pneumatic tyre version of this for us poor souls cursed with terrible road surfaces. I'd also love to see compatibility with Original Skateboards spring trucks.
But anyways fantastic product, I'll definitely be picking one up at some point.
On the image showing the brushed vs. brushless... How much of that size difference is due to gearing? A scooter shaft's output is much lower RPM than a skateboard. Your gearing seems to be via belt drive.
You're right, there's a gearbox on the brushed motor and not on the brushless one. The gearbox is the part with the shaft sticking out, and the motor is the part with the heatsink fins.
And you can buy the motors already! We are using a slightly modified version of a RC airplane motor. Our first prototypes used motors we bought at a local hobby shop.
I really wish the city I live in has much better bike lanes or sidewalks so I could use this thing to get from point a to point b further than just my suburban neighborhood. I can't wait to see people riding these things in the city.
I wonder if they ever considered hub motors for better efficiency and quieter operation (no belt), or would it be too big technical challenge to custom-build (basically the wheel and motor would be single integrated unit).
[+] [-] staunch|12 years ago|reply
[+] [-] skdoo|12 years ago|reply
Just like a car or motorcycle, right now there's a floor to how cheap it can be and still be great. If that gets lower over time, all the better.
[+] [-] dmd|12 years ago|reply
The Kickstarter says 20 mph, 6 mile range, 2000 watts, which gives an energy of 600 watt hours.
A Macbook battery is around 60 watt hours, and weighs about 1.5 pounds; 10 of those would weigh 15 pounds - and take up a ton of space. I don't see the volume of even ONE in any of the photos I've seen.
Where's 600 watt hours of battery hiding?
[+] [-] skdoo|12 years ago|reply
[+] [-] Jack000|12 years ago|reply
[+] [-] zwieback|12 years ago|reply
[+] [-] pocketstar|12 years ago|reply
[+] [-] jacquesm|12 years ago|reply
[+] [-] doorhammer|12 years ago|reply
Biggest downside I'm wondering about is only being able to use it when it's dry out (not sure there much to be doe about that while staying reasonable).
I'm a fairly avid cyclist, though. I think than between a boosted board and my trusty bike, I'd cover a pretty huge swath of my use cases.
Really interested in this.
[+] [-] oneiric|12 years ago|reply
With this at least you could wear boots because you wouldn't have to kick/push/coast.
[+] [-] robomartin|12 years ago|reply
The motors being used for this project are hobby model aircraft motors. These motors put out a lot of power per unit volume but are most definitely not designed for continuous duty at anywhere near to full output. They are also not sealed against the elements and have bearings selected for reasonably balanced loads with relatively low radial loads.
I have piles of these on my workbench ranging from cheap Chinese units to top of the line German designs. I use these on our planes, helicopters, multi-rotors, boats and cars. At the top end you have amazing hand-crafted quality with a prohibitive price (unless you want to pay $8,000 for a skateboard). At the low end they are cheap and they are junk. I've seen everything from magnets coming off, coils burning out, power leads coming off, bearings going bad prematurely and shafts bending.
In short, while the design process is interesting, I think the most fundamental flaw is being ignored: The motors are not designed, nor are they suitable for, this kind of an application.
[+] [-] kunai|12 years ago|reply
What are the safety concerns of something like this? A top speed of 20mph will definitely be unstable for general usage, and even 15 seems more like bicycle territory, where you're seated and have an aerodynamic shape.
We might see many people falling off of these in the future...
[+] [-] penrod|12 years ago|reply
The main issue with skateboards is 'speed wobble' vibration in the trucks, but a well set-up board generally isn't prone to this.
[+] [-] mike_esspe|12 years ago|reply
Lightweight electric kick scooter could be useful to larger audience as a "last mile" solution.
[+] [-] 8ig8|12 years ago|reply
Edit: Not mine, but these look nice: http://www.goped.com/products/Electric.asp
[+] [-] reneherse|12 years ago|reply
[1] http://www.blessthisstuff.com/stuff/living/misc-living/longb...
[+] [-] ballard|12 years ago|reply
A go pro video of going from Filbert and Lyon to Filbert and Van Ness, now that would be rock: http://goo.gl/maps/OlHc7
For those that don't live in the city, it's one of the steepest streets in the western hemisphere.
[+] [-] nl|12 years ago|reply
The 11% average over 1km isn't too bad, but the start looks pretty steep. Strava shows it at up to 40%. That's not exactly 100% accurate, but I've ridden 25-30% slopes on Strava and they are hard enough that on my road bike I can't stay seated (the front wheel comes off the ground) and if it is the slightest bit wet the rear wheel slips when you stand.
I'd be very impressed if this can make it up there with a person on it.
[+] [-] nikatwork|12 years ago|reply
But anyways fantastic product, I'll definitely be picking one up at some point.
[+] [-] beambot|12 years ago|reply
Any chance you'll sell just the motors...? ;)
[+] [-] skdoo|12 years ago|reply
And you can buy the motors already! We are using a slightly modified version of a RC airplane motor. Our first prototypes used motors we bought at a local hobby shop.
[+] [-] ececconi|12 years ago|reply
[+] [-] Yaggo|12 years ago|reply
[+] [-] ballard|12 years ago|reply
http://youtu.be/U1scP9uZP9Y
[+] [-] pkorzeniewski|12 years ago|reply