OK, well the next update didn't happen until 6 years later, when we finally decided to retackle this project. BUT, this time around we wanted to really get it right. The 2007 version was built around an off-road mountain board which is appropriate for a motorized skate, but it's not very stealth and attracts a bit of attention on the road. What massively appealed to me was making a slick build that looked like any non-electric longboard. What also appealed is making something that could conceivably be a retrofit 'conversion kit' for longboards just like we do for bicycles, and that similarly embraces the idea of using standard longboard hardware throughout.liveforphysics wrote:I'm excited for the next update on this project my friend!
Perhaps! That's all assuming I can get it up and running by this weekend.EBJ wrote: Would love to see some more of this thing.
Perhaps you will have it at the Bay Area Maker Faire?
This particular deck has enough of a tail that it could be possible to run it in electric 'manual' mode once you lift the front up! I don't think I've done an ollie on a skateboard since I was like 14, but will give it a shot and see if I or it survives. It's pretty easy to swap the trucks around between the front and back.flathill wrote: Make it fwd so you can still ollie
Or ride in reverse and drift
That's a valid concern. It's a pretty snug press fit as well. However, these are cheap turnigy hobbyking motors and that spacing between the magnets is anything but uniform, so I'm sure that there are a only couple that are taking the bulk of the load. However, if those start to chip a bit then the load will get quickly distributed amongst all the others too.Is the torque from to motor only coupled through the magnets or is the coupler also a press fit
Seems the magnets may crack or come loose
Neo mags are only strong in compression
No, that would be nice. Next time I will definitely use higher grade motors as the starting point, since the hongkong hobbycrap is always a disappointment once the novelty of being super cheap wears off. They've also got fairly poor no-load losses, just running the motors unloaded for 5 minutes and they are hot to the touch.Scorpion motors? If so nice choice
Awesome link, I wasn't aware that someone had been compiling these builds, and nice to see that our original attempt from '07 made the list!sk8norcal wrote:wow, that's pretty crazy.
I am not a believer yet in weight sensing e-boards, seems like the holy grail for sure.
Had a very brief try on the Zboard.
there is also Goboard, and a couple of other attemps here,
That looks super nicely done too, though I'd love to hear how well the RC motors hold up being the actual wheels and dealing with all the impact forces to which a skateboard wheel is subject. But if they hold up well and if the rubber is easily replaceable as it wears down, then that may be the better approach. Here are the relevant skate hub motor images from the above links:seen this other two eboards with hub motors?
Chalo wrote: I gotta say, this is the first e-skateboard related post here that didn't only make me want to go watch some more skateboard fail videos on Youtube. Weight-shift based control of a powered board is also the first thing I've heard of that might make skateboarding a slightly less terrible idea.
I pretty much agree with this assessment too. The idea for this board is to have a ~500 watt power level, not a multi-kW machine, and for that the natural kinetic interface of leaning forwards and backwards for acceleration should meld perfectly with the way you lean left and right to steer on a skatebaord. But at higher power levels I don't know if I'd be so comfortable with it. There is a bit of built in negative feedback though which you don't get on a throttle control. As the board takes off, the acceleration puts your weight over to the rear again, causing it to slow down, and so this build in damping could be beneficial with the higher powers.sk8norcal wrote: actually, i would be more nervous to try a high powered weight shifting eboard than a hand control one.
a low powered weight shifting eboard can definitely be easier for a beginner vs a regular skateboard,
dont have to learn how to push or footbrake. (this is true for hand control eboards also)
The analogy is probably pretty similar to ebikes too. I used to believe I preferred throttle control over a torque sensing pedalec style ebike. But then, once I started riding more ebikes that had nicely integrated pedalec I realized that for the most part this was a nicer and more natural control interface between the human and the bike, since it's using the same input (your leg power) that you already use. Similarly, since leaning is such a core part of how you maneuver a skateboard (or surfboard, snowboard etc) I think that it would be a more natural control extention for motor power than moving one of your digits across a throttle. If you've ridden a throttle controlled board, you learn quickly that you need to lean forwards first before you engage it or the board will shoot out from under you. So the leaning already has to take place, and the brain has to learn to do that first in anticipation of you hitting the throttle.xenodius wrote:Despite the cool-factor of a weight-sensing throttle, I think I'd prefer a tiny little remote hand-throttle like these Kickstarter folks use:
yeah, that would be holy grail #2, kick-assist.justin_le wrote: You also touched on one of the other things that I want to explore, and that is the idea of still using the motors as electric "assist", while you still push the board by kicking, but have the motors there to level out the terrain.
Gyroscopic sensors and a FPGA could achieve thissk8norcal wrote:
yeah, that would be holy grail #2, kick-assist.
you are spot on regarding the weight shifting with high powered setup,
my back leg gets sore when riding the boosted.
here's holy grail #3,
carving and pumping.
there is a lot of fore/aft weight shifting going on,
experienced riders would not like to be lock into a 50/50 weight distribution at all times.
carving under acceleration? deceleration?
this area is where i have major doubts about whether the board will work smoothly with the rider.
With respect, I disagree for longboarding. In the case of longboarding its pretty typical to shift your weight forward when accelerating downhill, especially when fighting a wind resistance.sk8norcal wrote:that's the thing, leaning to turn is natural. Leaning forward is unnatural to a skater.
leaning forward to accelerate is something completely new.
I would agree with you on this one, but if anyone is going to make a "lean to accelerate" skateboard to change my mind, it's going to be Justin.xenodius wrote:Despite the cool-factor of a weight-sensing throttle, I think I'd prefer a tiny little remote hand-throttle like these Kickstarter folks use:
I'm not a fan of software-controlled "soft-starts" of "soft-stops". I rode a popular board that boasts such features, and it was one of the scariest electric-skateboard I have ever ridden. I prefer a direct-drive "instantaneous" throttle-response. It seems like a "traction control" vs "no traction control" argument, and I guess I'm a "no traction control" guy.sk8norcal wrote: Also having a 'soft start' helps alot with this issue,
I have not yet hit the physical-limit of acceleration. With decent grip-tape and the willingness to lean forward, I imagine it would take a lot of force to shear a rubber-on-grip-tape connection.sk8norcal wrote: There is only so hard u can accelerate an eboard anyways, (nothing to grab on to, unless u nosegrab)