Technical Progress Part I: Electronics

The motor control electronics have changed significantly since our Kickstarter campaign, and today we're going to show you their evolution from prototype to (almost-)production. This has involved the design of printed circuit boards (PCBs), the software in the motor controller, and the mechanical design and manufacturing of the heat-sink and protective cover.  
Evolution of prototypes, starting with the initial off-the-shelf electronics version and progressing through custom electronics revisions

Off-The-Shelf Electronics

Boosted's drivetrain uses brushless motors, which are smaller, lighter, quieter, and more powerful than normal brushed motors. The trade-off is they require more advanced hardware and software to correctly control them.

The first batch of boards we built last summer used off-the-shelf motor controllers, a small custom PCB, and an Arduino. These were all enclosed in a laser-cut acrylic and cloth enclosure and controlled by a hacked wireless Nintendo Wii Nunchuck. Testing with these units was invaluable, but major problems made them difficult to use and required frequent repairs and maintenance. Issues included:

  • jerky operation at low speed
  • electrical components vibrating loose
  • electronics booting up in "braking" mode if you pushed the board while it was off
  • the enclosure cracking easily from minor impacts
  • switches that could change position due to shock
  • loud motor operation, especially during braking

We listened to feedback from our early testers and thought about the safety implications of some of these problems, and we realized that we couldn't use these off-the-shelf electronics for our Kickstarter boards. So we began working on a completely custom motor controller from scratch that could handle the high power output of the motors and still provide low-level software control of the riding experience. 

Early prototype board with off-the-shelf electronics that weren't usable for Kickstarter boards.

Custom Controller

Our first custom motor controller used one PCB and microprocessor for each motor and was controlled by software that we wrote in C. We left off a protective cover to maximize airflow and used connectors between modules so we could swap parts if anything failed. Despite some problems, the end result was a functional motor controller that provided smooth start-stop, reverse mode, quieter operation, and torque control instead of speed control of the motors, all of which were praised by our testers when compared to the off-the-shelf prototypes. You can see one of these custom prototypes in the photo below.
Our first custom motor controller in front and subsequent enclosed revisions behind it

Beta 1

Over the next few months, we fixed issues with the custom design and added important hardware, such as a current sensor and an integrated radio receiver. We also compressed everything onto a single PCB and microprocessor. After some intermediate test units, the first batch was built up in April and delivered to our initial beta customers. Along with field testing the betas with some of our Kickstarter backers, we've tested them ourselves and watched for issues due to electrical stress from high currents and motor loads or mechanical stress due to shock, vibration, and flex from riding. We've also brought the beta boards back into our shop for regular inspections and tune-ups. Enclosed motor controller designs with the enclosures removed

Our physical cover design wasn't ready for molding yet, so we quickly made temporary covers by heat-forming sheets of laser-cut ABS. The beta units all had a flat sheet heat sink, while in our lab we started experimenting with finned heat sinks for better cooling.

Beta 2

The next revision of the PCB saw many small but important changes that shrank it, improved its performance, and made it more reliable.  Software has been tweaked and can be updated on earlier beta boards in our shop. And the mechanical design of the cover and heat sinks progressed from sketches to CAD models to paper mockups to 3D printed plastic and finally injection molded plastic and machined metal. This process involved long hours spent by John, JF, and George both in CAD (using Solidworks) and with physical mockups to ensure proper fit. Various stages of the electronics enclosure design: including paper, heat-formed plastic, 3D-printed plastic, injection-molded plastic, bent sheet metal, and machined metal.

Injection molds were machined in Minnesota and we decided to test three different plastics for the enclosure cover to see how they held up to impact and abrasion. The latest boards were built using these molded covers and the newest PCB revision, and they've been delivered to our second group of beta backers. Barring any unexpected issues, we'll make one last minor revision to the PCB to improve manufacturability, and then ship it and the current enclosure design on all our Kickstarter production boards. Three varieties of plastic covers (glass-filled nylon, regular nylon, and transparent polycarbonate from front to back). 

As you can see, this is a complex process, thanks to a combination of factors like unique electronics and software, thermal limitations, and demanding environmental conditions. But the end result is a functional, lightweight, reliable, and beautiful electronics package. 

We'll soon have similar blog posts about our drivetrain, battery, and remote as those get finalized... stay tuned!

In the meantime, for progress on our beta testing and manufacturing, check out our update.

69 responses
When do you think we can see the boards go to sale. I'm ready with the deposit and looking forward to a boosted board for Fort Lauderdale Florida! Maybe even a distributorship?
Its great you are taking so much effort in testing the boards, Im sure it will be worth the wait. So looking forward to getting my hand( & feet) on one of your boards. Huge respect for following your dream guys, keep up the excellent work :)
Really good and comprehensive work you guys are doing! Thanks for sharing this, it's really interesting and fun to see the evolution of the product like this. Makes me want one even more!
Great job, cant wait to see more..
Here is a little insight from a consumer who can see your vision and what I would rather add/eliminate. 1. Why not eliminate the wood board and incorporate carbon fiber/gun metal and have the battery and electronics be the board? 2. A wireless charging stand/mat using similar technology used in smart phone accessories. Or the same frictions charges the battery for no charge necessary. 3. An Apple and Android app that wirelessly controls the board as well if controller is missed placed. 4. A magnetic mechanism for placement of controller when not in use. 5. LED lights with white, ambient, and brake lights. 6. A GoPro docking system accessary. 7. Mountain board wheels for off-road riding with a customizable tension within suspension. 8. Foot straps to keep rider attached. 9. Wireless, bluetooth, water resistant, mini speakers. 10. If we could custom tailor every part of the board, to graphics, to material, design of board, wheels, color, and so on on your website that would be great. Out of all the competition, you guys have the best design and ingenuity yet. You can be the new Ford of the mini electronic transportation devices. I only hope that you may envision this in a global and affordable scale similar to the Nano car.
Looking forward to the release of your very exciting board. Keep up the good work!
So impressive to see your quality R&D approach to making the Boosted board design the best in everyway. Looking forward to getting one. Have you considered die casting the casing in aluminium or does this cause RC/RF interference issues?
Not to offend, Carlos, but all those ideas sound a bit yuk. The brilliance of this thing is its simplicity and functionality (and you guys making it have been nailing it). Loaded decks are super fun to ride and stiffening them with electronics integrated in the board would be a mistake, and I don't know about anyone else but I don't want a board stuck to my feet if I'm coming off on pavement. Lights, speakers, inductive charging, all additions that would reduce batteries and increase weight. Just the board, motors, batteries and a simple, robust, minimal control system is perfection (read - keep doing what you're doing guys!). Oh and a lanyard for the controller & hot swappable batteries...
You guys should TOTALLY put LED lights on it! Just a few white 1W'ters on the front and a red one on the back. And maybe adjustable brightness with PWM and a few flash modes. This way you can ride at nighttime, and improve visibility/safety when riding at any time of day! I made a elec skateboard (http://cladlab.com/electronics/projects/electri...), and the lights I put on it was one of my most valued design decisions.
It would be a good thing if you had replacement tires for the back.I'm sure the tires have to have CNC machined holes in a bolt pattern through the wheel.Don't put lights on them,I don't want every cop around pulling me over.Keep up the good work.
Put a replaceable slider on the bottom part near the wheels, because that's gonna get scratched. Any type of slide or guard would work, should be replaceable cheaply when necessary, and simple to install (1-2 bolts :) ) Looks awesome, gonna get one to replace my elektoskate, which has also served me well on a daily basis for the past year, saving me about an hour per direction on my daily commute :)
Can't wait to try this out ever since I saw you guys speaking at TED!
Very cool. I canceled my order for a ZBoard because I think what you guys are doing is even cooler. I agree with some of the ideas from Carlos Amaro earlier -- why not make the board itself the container for the battery and electronics? If properly shielded you would have an ample area for a custom battery (expensive, but key). Granted I don't know much about skateboards -- I just want a good intersection between too-long-to-walk-to-work and not-wanting-to-sweat-through-my-clothes on a bike/board right now. But it seems the volume of the board could be a nice area to house gear rather than just being empty wood. I definitely agree that a place to store the remote control is going to be absolutely key -- something magnetic and easy to locate would be great, otherwise you're going to get lots of people asking for replacements. Braking lights or really any illumination would be neat -- perhaps have ambient sensors that enable them during the darker hours for safety and visibility. It would add weight and drain the battery more, but LEDs and tiny sensors are not very heavy or expensive as they are in all smartphones nowadays. The one thing I absolutely think is key to the future leader of the e-skateboard market is water resistance. I work in a lot of places that tend to have rainy weather during many parts of the year (NYC, San Francisco, Wellington NZ, London). I don't need a board that can be fully submerged, but something that can handle a regular splash of water up from the pavement, I think, will separate out the true winner in this arena. Not all of us live in southern California where the sun is shining all of the time. Good luck guys, I'm excited to see how things play out.
Here are my 2 cents. The reason why it isn't feasible to enclose the PCBs and the battery within the deck is because that would compromise the bendability and the uniformity of the deck. The bending of the deck pretty much acts like a natural suspension system. Electronics wouldn't last long as a part of a shock absorption system. I believe this is also one of the reasons for placing the battery and the PCBs as close to the trucks as possible. The grip tape on the deck provides, as the name would suggest, grip and suffices the need for straps. Induction charging isn't as practical as it is aesthetic, but that's only my opinion As for apps, think phonecalls Swappable batteries would be awesome though
i need this in mexico.!!!
i need this in mexico
+1 for swappable batteries. The 6 mile range is a problem for me personally. I've got a 7+ mile commute and I'd love to use one of these to get there and back, but that last mile or so has me hesitating to drop the scratch. Add a swappable battery and take my money!
Hey guys I think your board design is amazing and I intend on buying one once you put them into full scale production. As recent industrial design graduate I can really appreciate the amount of work and innovation you guys have put into this. I have some thoughts I wanted to share with you. For your heat sinks if you are still having issues with overheating then look into pin fins for cooling. They are more efficient at cooling than traditional fins due to increased surface area. Also have you thought about a way to disengage the belt from the motor. Perhaps an electronic or manual option to disengage the drive train would enable easy pushing when your battery dies. Although with a range of 6 miles it may not be worth all that engineering. Lastly I think it would be awesome to incorporate solar panels into the board. New solar panels are thin and efficient enough to be able to inset or place them on the top or bottom of your board with minimal weight gain. You may not use your board for a day or two and forget to charge it but the solar panels will have already taken care of it. Most new solar panels can even use interior lighting for a trickle charge. Imagine hanging out in a park and letting your board charge up giving you a few more miles before you go. I believe this would help to further expand interest in your boards making them even greener. If anything it will spark interest in the capability of solar technology. Perhaps you could even obtain government incentives due to the use of solar and offset the price of the panels.
How about replacement batteries? Or a quick way of interchanging batteries on the go.
I'm in the keep it super simple camp. All the bells and whistles some like to see I believe complicates the simplicity of an electric board. Brake lights? Just clip a 10 dollar blinker to your belt and call it a day. Headlamp? Velcro a Bell bike lamp underneath the nose - easy on and off. Also, the integrated board idea while neat, compromises the modularity of the design, something that you want to have for repair and replacement. I think the most important addition is the idea of hot swappable batteries. I can't imagine running out of power on the way up the Manhattan Bridge. My round trip commute into Manhattan is 10 miles. 7 mile limit has me looking for places to plug in. Hot swap would really open the market up to city commuters.
Don't confuse efforts with results. I am still waiting for mine... when will it deliver? Who knows. Meanwhile, here's a board with better specs, shipping NOW: http://evolveskateboards.com.au/pages/specs Wish I had researched more and not been duped by Silicon Valley vaporware and hype.
Agree with some Ideas from above and new ones: 1 - Swappable Batteries 2- More durable guard of battery and electronics - looks like you would break the case going off a curb. New Ideas: 3-Sell just the trucks/battery/electronics to place on your own board. Just include a template of where to make screw holes for mounting. 4-What about a wearable battery extender, like backpack or leg strap that can be connected on a magnetic cord (so that it will detach incase you have to get off the board.) I know this would limit the persons mobility and there would be a chance of catching on the wheels, but could potentially increase the range multiple times over. If designed properly since the front leg is mostly stationary even when manually pushing (sorry for all you front leg pushers).
any plan to make this great project open source/open hardware ?
I have seen other electric skates and is exactly why I am here. Design simplicity. Swappable batteries would be my first choice, then I could ride to work and back, WOOT! Talk about a smooth way to ride.
To Me, the most important electric vehicle project on the planet. More people are going to use this personal transport tech than anything.
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