Electrically-Powered Mountain Board

Mario said:
The motor is .5hp. With a 3:1 gear reduction, that's 1.5hp (ideally) and 20mph at 3000 rpm. The weed whacker on my bike is about 1.8 hp and propels me at 30 mph. I think I'll have enough power.
*smack* HP is a measure of power and thus equivalent to watts. HP is a product of torque and how fast it is delivered. I would compare torque to amps and RPM to volts. So with gears, you are keeping the same HP (minus efficiency losses, of course) by changing the speed and torque. If your reduction gives you about a 20mph top speed, that should still give you some go power at slow speeds without stressing the motor.
robm said:
Hmm... seems an awful lot of slack in the chain?

And what's the progress, yo?
Very yes, but it looks like a large enough chain that it might be ok.

And give progress report, now. I have wanted to make one of these for a couple years and I now have moneys.
 
Yeah, I realized my mistake after I posted that, since hp is a certain amount of power over time. I figured most people wouldn't see through my silly logic, but you did. ;)

It is a lot of slack, but one link shorter is /just/ too short. It's not that loose anyway, and yes, it is a thick chain. It's #40 roller chain.

Progress? Reading back, I realize I forgot to tell you guys that this thing totally works and is awesome to ride. :awesome: I have a GoPro camera, and got some nice shots with that mounting it on the motor and the battery cover. I just need to put together a video. I might do that sometime this week, but don't count on it.

Vskid, just so you know, this whole thing was about $510 -
Battery: $290 off ebay with quick shipping
Board: $100 used off craigslist, had the brakes
Motor: $70 off ebay, but I saw the same one go for $35.
Motor brackets: $50, cause I don't have the tools to make them myself.

Everything else I already had. The battery was $250 before I got impatient, so there's some money you could have saved. The battery would have taken a month to get me, though, instead of a week.
 
Not bad at all. I would have to have all the parts shipped home so I could work on it when I'm home for Christmas (no tools here :cry4: ). I'll have to check if they're legal here. I saw a sign on a bike path that specifically said "No Motorized Skateboards" in the list of prohibited things. Good thing I'll be riding a motorized mountain board. :trollface:

How much research did you do on motors and controllers? If I built one, I would like to have regenerative braking because there are so many hills around here. Just wondering if you may have found a controller that supports it.
 
I was originally planning on having to buy a motor controller or building one, but after looking on ebay for brushless motor I stumbled on this one, which has a built-in controller. You just attach 24v and a pot as a voltage divider, and it goes. Very smoothly, I might add. I say a video of a motor with a built-in controller, and it only has five speeds, even though the pot is analog. This motor has very precise control, though.

Regenerative braking? I wouldn't bother with it. There may be a lot of hills, but unless you are taking this thing on 3-hour trips, I doubt it would be a good feature. The battery takes about 4 hours to charge, and regenerative braking is not very efficient. Besides, you would have to make a controller that supports LiFePo4 batteries.

By the way, the whole board weighs 30.1 pounds. It's not unbearable to carry, but it's not fun.
 
Bump. Because I want that video. And battery life specs? and stuff. How is holding up? Battery life at speed? Etc.
 
Okay, first, sorry i didn't reply sooner. I almost never go in here. :p

And I totally forgot about the video! My dad and I shot some clips, and he was gonna make them into something but he didn't get around to it. I'll ask him about it again.

The whole board is basically still as good as new. I got a sticker in the drive tire, so I need to pump it up whenever I wanna take it out, but it'll hold the air for several hours.

The drive tire is worn a bit, but that's to be expected. I'm using dirt tires on pavement. I may buy a set of street tires.

But other than that, everything is working fine! Battery is still great. I'll try to get a video up.
 
How much do you ride it? I got a car, so I pretty much gave up on making an electric mountain board for the time being. Maybe in a year or so, depending on where I live then.
Can you easily remove the tire from the rim? I would take it off and patch it up, just so you don't have to pump it up every time you take it out.
 
It doesn't take too long to take it off and put it back on, maybe 15 minutes. I really only use it for fun, because the only place I could take it is school (but that's pretty far and I have a ride anyway).

Nowdays I ride it probably every week or so, for about an hour.
 
Well, my dad was making the video when his computer crashed. No video tonight. :confused:
 
budnespid said:
If we had smooth roads in Mississippi, I would so totally copy you. :awesomemario:
It's a mountain board, you don't need smooth roads! :awesome:
It looks slower than I imagined, but anything faster would probably get out of hand pretty quickly.
 
vskid3 said:
budnespid said:
If we had smooth roads in Mississippi, I would so totally copy you. :awesomemario:
It's a mountain board, you don't need smooth roads! :awesome:
Allow me to rephrase that. Roads with less than 50 potholes per mile. This flax is ridiculous down here.
 
vskid3 said:
budnespid said:
If we had smooth roads in Mississippi, I would so totally copy you. :awesomemario:
It's a mountain board, you don't need smooth roads! :awesome:
It looks slower than I imagined, but anything faster would probably get out of hand pretty quickly.
I didn't get quite to full speed in that video. Probably around 15mph, when it can do 20. But yeah, at higher speeds it's amazingly easy to get speed wobbles. I ate it at 20mph once like that, and it's not something I wanna do again. :p
 
Hm, makes me wonder if I should make one or abandon the idea. I mean, it seems fun, but I can think of other things I would rather do.
 
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