Hi everyone!
I’m looking to make an E-board for commuting purposes, but I have some unique circumstances that I think might lead to unique priorities in the design and component choice.
The main issue is that I have suffered a couple of relatively severe injuries in the past few years that have left me with certain physical disabilities. For the most part I can work around my limitations and you wouldn’t be able to tell that anything happened if you saw me on the street, but I still have to think very carefully about the pros and cons of pretty much any physical activity I want to do, particularly if it is something as potentially dangerous as an electric skateboard.
Injury wise, I have weak ankles because I broke my back and paralyzed myself for a while. Most of my muscles came back to 80-90% strength, but my left ankle is pretty much useless and I can’t run all that fast. As far as skateboarding goes, this means that I can’t really balance on one foot and propel myself forward with the other, and it means that I shouldn’t go very fast because I can’t jump off and run it out at higher speeds. That being said, I can ride just fine if the propulsion comes from elsewhere (e.g. I can still snowboard fairly well, and I can easily ride a longboard down a hill).
So in light of all this, here are the pros and con.
Pros:
-
An electric skateboard would help me get around town. It isn’t easy for me to walk long distances. I can do it, but it’s a chore. Imagine having to run a mile or two every time you wanted to go someplace - it’s doable, but you have to be pretty motivated and you end up at your destination seriously drenched in sweat. Because of this I rarely go anywhere without my bike, but that still leave me sweaty and more importantly it isn’t nearly as portable. Which leads me to #2…
-
I can take an electric skateboard with me on airplanes and public transportation. I honestly don’t mind the workout, and I would be perfectly happy with my bike if not for the fact that I can’t easily travel with it. Whether I’m taking a bus to another city or flying to a different country, I have to leave my bike behind deal with the city as a pedestrian. I travel quite a bit for work and for fun, and again, while I manage just fine - it’s just quite the chore and it would be awesome to grab my skateboard and have options.
Con:
- Increased chance of injury. I’m terrified of this one. I’ve already hit the ground hard a couple of times because of oddball sports that involve a certain degree of speed (I broke my back and paralyzed myself for a while while skydiving and then I later shattered my wrist paragliding), and I’m very wary of doing things that increase my risk of something like that happening again. That being said, I still want to live life so I’m still willing to take on risks if the benefits are significant enough and if I feel like I can be reasonably careful and keep the odds reasonable.
So finally and without further adieu, here are a few design priorities I have for my electric skateboard and why:
-
Good torque, good range and a boring top speed. I live in a city with a decent amount of hills so I need good torque to get up them, and obviously range is good just because I would like to get through a day without having to worry about finding time to recharge it. But the last thing I want is a high top speed. I’m basically looking for something that is about as boring as a Segway but isn’t ridiculous looking or prohibitively expensive. I don’t plan on going much faster than a comfortable pace on a bike. If there is no way to achieve decent range and decent torque while limiting top speed then I can just get something fairly powerful and use self control, but ideally I would like to end up with a motor system or a drive train that is somehow tuned for torque and efficiency at the expense of top speed.
-
Reliable and powerful braking. If it comes down to it, I’m confident that I can jump off and run/roll it out and I might even have a chance at learning to slide stop a long board since I have a lot of snowboarding experience and the injuries don’t seem to have affected that too much, but for the sake of comfort I will be using the motor/s to keep me from speeding down hills and generally relying on them to stop me.
-
Light, portable and legal to take on airplanes.
So I have a few questions about how to achieve this:
-
Is there a way to tune the motors and drive train for torque and distance at the expense of top speed? What combination of motor(s) and gearing is best for this? Obviously a low gearing will lower top speed and improve hill climbing, but how do these motors handle the increased RPM in terms of power draw?
-
How reliable is braking on DIY boards? Can you even get regenerative braking? I know that some retail models will actually turn off the braking function if the battery is too full to avoid overcharging it, and I imagine that engineering a solution to this might be beyond the scope of a DIY project.
-
How reliable is the wireless connection on DIY boards? I would definitely want to minimize dropped connections, and I’m worried that cobbling together a bunch of third party parts would not be good for reliability.
-
Can issues of reliability be mitigated somewhat by having dual motors for redundancy or by using quality components? Obviously I’d like to get a good price, but I’m also willing to spend the money if it has an effect on reliability and safety.
Thanks!
