Electric Mountain Board

Step 8: Project Notes

Here is a short video of the board in action.

Total time to put this together was about two days and then several more getting the chain tension just right.

I'm not sure of the battery duration or range but I have ridden it for up to 45 minutes without having to charge it.

If I had it to do all over I think that I would have made it just a bit faster. Its still fun the way it is though.

Comments

[DustySeven7]

you can use RC batteries, you have to wire them in series and then a parallel.
These guys took a electric longboard using CIM motor.
http://www.instructables.com/id/Electric-Longboard-Build-Clever-CIM-Motor-Drivet/

here is the battery they used http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=6518

the battery wiring is on step four
if you wanted to use the motors they used look at step 5 and 6

[SystemZERO]

What's the top speed on this beast?

[Vurp]

Doing the gear and motor calculations top speed is about 10-11mph or 18-19kmh which seems about right. I have been thinking about ways to increase this without spending too much more.

[Spokehedz]

Make the gear on the motor bigger. That'll increase the speed, but will reduce the torque--something electric motors have plenty of anyway.

[arf200]

or lower the gear on the tire. same efect though

[computerwiz_222]

True, but the more torque you demand, the shorter the battery life and the take off speed will be slightly slower because the motor has to build up "momentum" In other words, the motor has to overcome the stopped friction. Friction when the device is stopped, is much higher than when the device is already moving.

[Spokehedz]

Why not push off with your foot for the first couple of feet, and then turn on the motor gradually as you help it along with your foot?

[crakdos]

That's how mine works, but it is still not fast enough. I guess its time to make another one

[computerwiz_222]

well I guess you'll have to *sigh* {sarcasm} I love building stuff lol

[computerwiz_222]

lol that i never thought of that... Plus, why wouldn't you. When you skateboard, you push off...

[btop]

Heh, thats a good idea. Get yourself moving and then let the motor do the rest.

[Timofte Andrei]

dude this is a cool project...but! you should upgrade it ;) first of all...try to put that regulator with all the wires into a box to protect it from mud, dirt and humidity and then move one of that two batteries on the front of board ;) you should try a disk brake system if it's possible ;) sorry for my writing problems ;) i'm from Romania ;) peace

[Nosewalker]

 Vurp,
Thanks for your page again.
take a look at mine... and the next one will be better.

[Vurp]

That looks awesome, I like how you connected the motor.  It takes care of the problems with steering that I had.

[troublem8ker]

Could you use either 2 12v or 1 24 volt cordless tool battery to make this smaller? Are they of a suitable mAh, or are the lead acid type batteries what you need?

[frontier]

dosent matter which battery type it is. as long as it can support the mAh drainage. it will only affect how you charge it. to making it smaller etc or less clumbsy you could mount batteries on the bottom of the deck etc.

[shanemac]

i guess you could stack parallel and series 9.6 volt (600-900 mAh) RC NiCad RC bateries - this would give more juice in a smaller ligher package - and they've come down a lot in price lately... it would also be nice to use a double 400watt motor config - front and rear

[troublem8ker]

You couldn't use RC batteries with that low of a mAh. I believe that 12v scooter batteries are like 10,000mAh or something like that. You would probably have to go with larger batteries in the C-D range. RC batteries are usually AA or Sub C soldered into packs. It would definately make for a lighter and more easily replaceable alternative. You can buy individual cells and put together your own packs. A 24v pack would be 20 1.2v SC batteries. You can get some D Size 10000 mAh high capacity NiMH Rechargeable batteries on the interweb for about $8.50 per cell. These have solder tabs pre-attached. It would probably cost you in the ballpark of $175 to build this pack (counting shrink wrap). At .36lbs per cell, it would probably weigh in at about 7.5lbs. Dimensions would be nearly anything you wanted, as you could stack and configure them to fit nearly anywhere. Side by side they would make a pack about 26 inches long, 2.5 inches wide and .75 inches thick (with the cells laying down). Figure you could stack half of them on top of that and you would get double the thickness, half the length, etc.

[shanemac]

https://www.all-battery.com/index.asp?PageAction=VIEWCATS&Category=176&OVRAW=Lithium%20polymer&OVKEY=lithium%20ion%20battery%20polymer&OVMTC=advanced&OVADID=1307492012&OVKWID=9511236012

any recomendations :)

[jeff-o]

You might also want to visit www.batteryspace.com and see their pre-made battery packs.

[shanemac]

great ideas thanks... i think i might make this a project :)

[Spokehedz]

RC Car packs can't get the high sustained amps that you need for things like this. They boil the electrolyte. Plus, with your calculations, he is paying 3x the cost of the SLA's--and it only weighs half. Not to mention that if one cell goes bad, the whole pack degrades that much quicker. For this application, Li-FePo would be the optimal solution. However, it is still quite expensive--but they claim that they will last 10 years. SLA's wont last that long, AFAIK.

[Vurp]

I thought about getting some of the Dewalt battery packs because I had seen them used on a bike. I went with the lead acid as a cheaper alternative.

[ego waffle]

awsome !! There was some thing like this in popular science magizing you should cheak it out!! by the way what was the toatal cost?

[Shantorama]

What is the turning radius... seemed pretty wide from the vid.

[Vurp]

I can turn corners easily but to turn all the way around takes almost the full circle of a cul-de-sac.