The Mini Maker Faire in Atlanta was packed with exciting builds and devices, but [Andrew’s] Electric Bubblegum Boards stood out from the rest, winning the Editor’s Choice Award. His boards first emerged on Endless Sphere earlier this summer, with the goal of hitting all the usual e-skateboard offerings of speed, range, and weight while dramatically cutting the cost of materials.
At just over 12 pounds, the boards are lightweight and fairly compact, but have enough LiFePO4’s fitted to the bottom to carry a rider 10 miles on a single charge. A Wii Nunchuck controls throttle, cruise control, and a “boost” setting for bursts of speed. The best feature of this e-skateboard, however, is the use of 3D-printed parts. The ABS components not only help facilitate the prototyping process, but also permit a range of customization options. Riders can reprint parts as necessary, or if they want to just change things up.
[Andrew’s] board is nearing the 11th hour over at his Kickstarter page, so swing by to see a production video made for potential backers, or stick around after the break for some quick progress and demo videos.
How on earth do 3D-printed parts of a production part ‘help to keep the cost down’? For these kinds of volumes it would be MUCH cheaper to have them vacuum cast.
They do when you’re printing the pulleys.
I don’t understand your comment. If they must be of a custom design and in plastic, vacuum casting the pulleys would be both cheaper and of higher quality than 3D printing them. 3D printing is really only any use for single digit runs.
Maybe he has plans to vacuum cast things if the kickstarter is successful. Is vacuum casting how plastic pulleys are typically manufactured?
Now that I re-read your comment, I think I agree with you: buying the pulleys isn’t exactly a financial hardship, and although printing them is cheaper in terms of materials cost, savings there is a drop in the bucket compared to the motors or the ESC.
It’s nice to be able to change ratios by printing out a gear with more / less teeth at home.
I’d hazard a guess that he simply doesn’t know about vacuum casting. 3D printing is popular and trendy at the moment, so other – often more appropriate – techniques get missed or forgotten about.
Plastic pulleys would normally be injection moulded. Moulds are usually in the order of thousands of GBP/USD, but then parts are tens of pence/cents. If you’re just making a few hundred copies of a part, then mould costs make the overall part costs prohibitive.
Vacuum casting is perfect for tens to a few hundred copies of the same part as moulds are very cheap, and parts can be made easily. There are tons of subcontractors who will make parts for you if you can’t be bothered to do it yourself. Oh, and you can include undercuts in your design, which you often can’t with injection moulding.
[youtube=http://www.youtube.com/watch?v=zlBM3zAl5gY&w=1280&h=720]
Ah okay, so it looks like a similar casting process to the one I use for propmaking. Cool. Thanks for that video!
And I was mainly concerned with the larger plastic parts, not just the pulleys.
The low-cost idea behind these boards is that each board comes with a USB drive with all the stl files needed to update parts, change colors and gear ratios without needing to buy more parts from me.
Can anyone recommend a company in the South Eastern US That can do this? The plan was always to use the Kickstarter funds to pay for injection molds, which are super expensive.
Andrew. Great work, by the way. I didn’t intend to be negative above, just quizzical about having to 3D print hundreds of parts when there are better options.
The USB stick sounds good, but you could as easily have them on a website; then files will always be up to date. Also, I wouldn’t presume that it’s easier or cheaper for folks to print parts themselves rather than buy them from you at reasonable cost – maybe I’m underestimating the number of skateboarders with 3D printers! If you don’t want the hassle of supplying spare parts, that’s another matter.
Indeed, it seems pointless to manufacture injection mouldings for only a hundred parts or so. It would even be cheaper to CNC machine them. Vacuum casting will be cheaper again.
For vacuum casting, I can’t recommend anyone in SE US, unfortunately. I’m in the UK, and only know local suppliers and ones in China. If you’re not opposed to trying China, try these guys: http://www.star-prototype.com They’re western owned/run.
I hope that helps, and good luck.
I really appreciate the critique. This is the perfect time for it too. Anything to save money is great. I have a list of vacuum molding companies I plan to call this morning to see what the prices are like.
You’re welcome. Do let us know what you find out and how things progress.
Andrew. Great work, by the way. I didn’t intend to be negative above (I’m James), just quizzical about having to 3D print hundreds of parts when there are better options.
The USB stick sounds good, but you could as easily have them on a website; then files will always be up to date. Also, I wouldn’t presume that it’s easier or cheaper for folks to print parts themselves rather than buy them from you at reasonable cost – maybe I’m underestimating the number of skateboarders with 3D printers! If you don’t want the hassle of supplying spare parts, that’s another matter.
Indeed, it seems pointless to manufacture injection mouldings for only a hundred parts or so. It would even be cheaper to CNC machine them. Vacuum casting will be cheaper again.
For vacuum casting, I can’t recommend anyone in SE US, unfortunately. I’m in the UK, and only know local suppliers and ones in China. If you’re not opposed to trying China, try these guys: http://www.star-prototype.com They’re western owned/run.
I hope that helps, and good luck.
Reallly neat with regards to compactness of it, 10 miles on a charge, awesome
I dunno how much more weight it would add, but when you’re going downhill would it be effective to maybe have some recharability? Does it matter?
Most ESC’s have some form of regenerative braking, but the efficiency is minuscule (less than 2-3%?). I think there are some attempts on the endless sphere forums to work out charging on downhill, but I can’t seem to find them at the moment. Probably would be in the bicycle section.
Projects like this make me wish I didn’t suck so bad at skateboarding. This is awesome but I would kill myself in 2 seconds.
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I’m having problems finding the charger for my board, anyone have a picture of it, or the model number? Would be very appreciated!