Posts Tagged ‘prototyping’

We need your help!

Thursday, May 21st, 2009

We did it!  Our team is in the finals for IdeaBlob.  And now we need your help.  Please, please, please take a minute or two and vote for us.  Every vote gets us closer to the $10,000 prize.  Precise instructions on how to vote can be found here.

Winning IdeaBlob will definitely open some doors for us.  Right now, we’re paying for everything out of pocket, which does limit our reach.  Although our stove is designed to be very low cost, the prototypes do cost a non-trivial amount of money.  (Raw materials cost more money when you’re not buying in bulk, and there’s some equipment we don’t have access to unless we buy shop time.)  But, the big cost is travel.

If you’ve read many of our blog entries, you know that our entire process revolves around end-users.  To do this, we need to work very closely with partners in the country, and we need to talk to our actual users.  Both of these necessitate at least one trip up front to do needs finding and to get face time with potential partners and to create a plan for our collaboration.  It’s not easy to do this without money for travel.

There are other avenues to funding, but every hour we spend trying to fund ourselves is an hour we can’t spend making our stove better.  It’s our hope that, with your support, we can win this and continue focusing on what really matters.  That said, we’d love to hear suggestions on other avenues of funding!  As always, you can get ahold of us at team@3brickdesign.com.

Thanks for your continuing support!

Frustrated by Frustums

Thursday, May 21st, 2009

Word of the day: Frustum-a portion of a solid that lies between two parallel planes cutting the solid.

Our inverted lampshade-like pot skirt is a frustum of a cone, or so we discovered when we tried to construct it from sheet metal. It’s not as easy as it seems; you can make a cylinder from a rectangle or a cone from a semi-circle, but a frustrum is constructed from a “rainbow”-shaped template whose dimensions determine the height and diameters of the part’s top and bottom surfaces.

pot skirt templates

Because we didn’t know that our pot skirt was formally called a frustum, figuring out how to build it was an adventure. Matt (a former teammate) and I had a friendly competition: he tried looking for the equation on the Internet while I made a barebones paper frame of the shape we wanted and then unfolded it to get a rough outline of the template. I like to say I figured it out first, but he found a neat little frustum dimension calculator that proved very useful for trying different pot skirt heights and widths!

I mentioned in my last entry “Skirting the Issue” that most pot skirts are actually cylindrical. So why in the world did we go through all this trouble to make such a tricky shape? There is an ideal gap for efficient air flow (about ¾”) between the pot and the pot skirt. When the team was in Myanmar, we saw that the women there cooked with an astounding range of pot sizes , with the smallest one having about a 5″ diameter, to the biggest one about 16″. To make matters more complicated, women often cooked on a wok as well. Thus, our pot skirt had to be designed to create the same ideal gap for multiple pot sizes. The “inverted lampshade” shape allows smaller pots to sit lower and bigger pots to sit higher on the skirt, creating a reasonable gap for air to pass through.

pot in skirtHowever, one of the difficulties with this design is that women have to reach further inside the pot skirt to take a small pot out. Since the air between the pot and the skirt is VERY hot, this poses a significant burning hazard for women. This safety issue is one reason why we are still hard at work at improving our initial concept!