Wireless Glove-Controlled Electric Mountainboard: An Analysis

Hey guys!  So I finally decided to make a page that has everything you could possibly know about my project.  Even though I had previously answered everyone's questions, they were usually through a message.  Because of that, I was usually asked the same questions and I figure making this instructable will mitigate that.  So without further adieu, here's the source!  If you still have any questions that weren't already answered, just let me know so I can add it!

Disclaimer:  I would NEVER EVER recommend that anyone use a motorized mountainboard with straps.  If you're wondering why I am saying this, it's because it was only after riding it for a while that I realized why everyone feared so much for my safety.  You'd have to be insane to want to build this and ride it!  I felt comfortable knowing I have years of experience in skateboarding, snowboarding, skimboarding, and surfing to really give me control of the board, but I never underestimated what I built nor did I ever forget about Murphy's Law.  Heck, even all my board experience wasn't enough for the 4 second delay that came from the PlayStation 2 controller when I was trying to stop the board.  I ended up cleaning the pavement a few feet with my leg, as you can see in the picture below.  In anything you do, always be careful, be willing to accept the consequences for whatever you do and when something happens, you have no one to blame but yourself.  So let me repeat this: I am not and will never be liable for anything that happens to you.

Now that we have that out of the way, let my project show you that when you follow your dreams, ignore the naysayers, and push yourself to your full potential, you achieve things that you had never imagined. People far too often underestimate their own strengths and skills, and many brilliant ideas end up just being an idea and nothing more. I want my project to show everyone that they can make anything a reality if they go for it. When I first started the project, I didn't really know about motors and I had to refresh my memory on some of the topics I learned in my classes. If you have the motivation, you can learn everything about a certain topic, as well as master it, and make it your own. Don't ever let anyone tell you that you can't do something if you truly believe in what you are shooting for.  All that being said, I'll leave you with what renowned Irish playwright George Bernard Shaw once said: "You see things; and you say, 'Why?' But I dream things that never were; and I say, 'Why not?'"

By the way, here is a link to a video of my board in action just in case you're interested: http://www.youtube.com/watch?v=686oJ7bNFIU

Step 1: Materials

Disclaimer: this is most likely what I used.  Now that I'm looking at the motor specs, I can't remember if I got a 1.2 or 1.6 since I remember the wattage that I got, but don't remember seeing the maximum voltage rating ever being lower than 26 volts.  But anyway, this was meant to be a guideline, not a step-by-step tutorial.  This project is dangerous from the start, and providing steps to a project I even had bugs on could give you a false sense of security, a belief that if it's online and everything is drawn out so nicely for you to follow along, that the finished product will be safe since that couldn't be further from the truth.  I wouldn't want you to get injured, and I definitely don't want to deal with lawsuits.  So I'll repeat this again: I am not and will never be liable for anything that happens to you.

Brushless Outrunner Motor
-RimFire 1.2: http://www.electrifly.com/motors/gpmg4505.html

Brushless Motor Controller
-http://www.hobbywing.com/product_show.asp?id=193
  +Can't find the exact one that I used, but I'm pretty sure this should do

Lithium Iron Phosphate Battery
-http://www.batteryspace.com/lifepo426650battery256v102ah26112wh40aratewithpcm.aspx

Arduino Duemilanove
-http://arduino.cc/en/Main/arduinoBoardDuemilanove
-http://www.sparkfun.com/products/666

SparkFun Flex Sensors
-http://www.sparkfun.com/products/8606

SparkFun NRF2401A Transceiver
-http://www.sparkfun.com/products/152
-http://arduino.cc/playground/InterfacingWithHardware/Nrf2401


I bought my board on eBay, and I think it's an MBX mountainboard.  The rest of the materials were either purchased at Home Depot (thick gauge wires), made from the ECE Machine Shop (casing for my battery, casing for the motor, and gears), or given to me from the ECE Service Shop (buttons, small wires, LEDs, op-amp).  Some of the board was also built in the ECE Machine Shop.

Comments

[csanders11]

I need helpppppp

[csanders11]

Also is the black box on the end of the top of the board an on/off switch for the battery?

[csanders11]

Actually I'll rephrase that. I'm new to circuitry and arduino. So I would appreciate if you could help me out with how you wired the flex sensor, arduinos, and transceivers. Also I need help with the programming for the 2 arduinos. I think it would be easier if you could just email me at [e-mail]

[csanders11]

Also can you explain the transceivers and how you connect them

[csanders11]

What do the 2 switches on the glove do?

[aguzmanballen]

One switch turns the glove on and off and the other one is a dead man's switch. It's basically a button that I have to hold down in order for the circuit to work. Once I let go of the button, it cuts the circuit's power and since the natural response to falling is stretching your fingers outward, the button will be released and the glove will no longer tell the board to keep moving.

[jmolina9]

Hi, some partners and I would like to know if there was a problem if we use a motor with a little less power than yours...??? How many cells does your battery has...??? Thanks a lot...!!! ;)

[aguzmanballen]

The motor I chose was definitely overkill. Yes I'd say you can get away with it and I even had a motor with less power than the one I currently use and it worked just fine. What's more important is the Kv rating for the motor. That and the gear ratios as well as wheel size determine how fast you are truly going to go. Even with my strong motor, I can't move from rest so you'll have to push yourself initially. That's why the power doesn't really matter since once you start moving with an initial push, the motor will take care of the rest. Although the strength of the motor will be more apparent (or lack thereof) if you're trying to start the board heading uphill. With the first motor, I was disappointed at how it didn't have that much strength going uphill unless I was already going at about 5 miles per hour. I hope this helps!

[jmolina9]

Hi it's me again, that advise was a good one, but right now i'm building the skate, and the thing is that I live in Colombia, so here its not so easy to get some stuff that we need. Right now we are working in the transmission set and we would like you help us with this, more o less. gracias por tu atención!.

[aguzmanballen]

Oops, I never responded! Well what kind of help do you need? I can answer questions if you have any; just send them to me via message.

[andresiten]

Hi! Very nice board man! About the engine, it's a 1.60 cause its says 63 - 62 (had to see the full-size pic). Again... nice board!!

[aguzmanballen]

Thanks; I appreciate it!

[tsalvadorai]

cn u plz make a video for me to understand better bcoz i dont understand....mayb a video for beginner.........anyway well done

[aguzmanballen]

Hey dude! Whoops, I overlooked this comment man, sorry! Anyway, what exactly was it that you struggled with? I could point you in the right direction whether it's programming, circuitry, physics, etc. I'd have to make a very long video to walk a person through the whole process. Plus, I'd be taking away from you the opportunity to learn ;)

[jackmcd007]

Would i be able to use two of these (http://www.hobbyking.com/hobbyking/store/__19616__Turnigy_L5055A_400_Brushless_Outrunner_400kv.html) as 2wd? If not i will just go with one Rimfire 1.20.

[aguzmanballen]

I think using just one Rimfire 1.20 will be enough. At first I thought I would've needed 2wd but it turns out that one is fine. Just make sure you choose the right gear ratio when making your electric mountainboard so that way you don't go too fast or too slow. Good luck!

[jackmcd007]

thanks!

[blenderking]

How did you make the wireless part from the glove to the board?

[aguzmanballen]

Well I found out there was an Arduino library for the NRF2401 transceiver, so I just read about it, bought the transceiver, and spent a few days debugging the thing and walah, wireless glove is integrated with the board.

[drkurtsvanhassenphefer]

This is really good. I've been wondering if you'd do something like this. I first saw your project on hackaday.com with the PS2 controller, and I thought it was cool back then. I thought adding the glove control was brilliant.

Now for my question. I'm doing some research for a project like this right now, and I'm having trouble deciding on battery voltage. Would you recommend something in the 36V range or something low like your 25.6V pack?

[aguzmanballen]

Thanks; I appreciate the comments! So with regards to your question, I had to try and figure that out too and it all depends on the kind of motor that you use, how fast you want to go, the gear ratios, how much you want to spend, etc. Because the RPM of brushless motors is linearly related to voltage, there is a sort of relationship between them that makes choosing the battery not that big of a deal, although it is nicer for your motor to depend on voltage to speed up as opposed to the current. So for instance the Kv rating was 10 Kv and we used a battery with 10 volts, then we'll get 100 RPM. It'll still spin 100 RPM if the battery was 20 volts but the rating was 5 Kv.

After working on my project, I found 25.6V to be the best for me. Motors can get to a low Kv, but those generally are much more expensive because they are very heavy duty. Those motors are generally bought when the person needs a motor with lots of torque. Also, you don't want too high of a gear ratio either since your project could get all cluttered up. Because of that, I did some calculations and found that with my given Kv, the gear ratios I had to use, and I didn't want to exceed the 12-15 mph range, I went with the 25.6V battery pack.

So I know I didn't give a definitive recommendation, but it just depends on many other factors. Usually go with the battery with a higher voltage, but depending on what it is you want to do, the highest battery voltage you want could just be the 25.6V pack.

[VinceJDJ]

Dude this is awesome!

[aguzmanballen]

Thanks dude!

[VinceJDJ]

You're welcome.