Last month the Milwaukee Makerspace power wheels team packed up the cars and road tripped to Maker Faire Detroit. After long nights working at the space until 4am for the week before the drive Ed, Kathy, Pete, Andy, Vishal, and too many others to mention got 3 cars race ready. The Bluth Stair Car, Super Tux Kart, and Hippie Rose made the journey to Detroit without damage are and were a blast to drive.
Our 3 cars raced with 34 others in the biggest Power Racing Series event to date on the biggest track ever made. It was great to see all the hard work paying off as the builders of the cars became the happy drivers of the cars. Both days of races were streamed live by our friends at Make Magazine to Twitch.tv where they can still be watched. Be sure to check out the race at Maker Faire Milwaukee September 24th-25th.
Check out the race from day one at the link below:
Make sure not to miss this weekend’s Nerdy Derby at American Science and Surplus. Adrian and the rest of the nerdy team will be helping kids and kids at heart turn blocks of wood into rolling masterpieces of speed. If you have not been to a Nerdy Derby event this will be one not to miss. 3D printed wheels have been coming in from printers all over the city and from our Makerspace 80 at a time.
Building a car is easy and there will be a nice long track to race down once you’ve finished your creation. You start by picking a block of wood and some wheels. After a bit of nailing its off to nerdy up your car from piles of amazing decorations. Makers are encouraged to decorate, test, and re-decorate. Everything that you glue onto a car affects the way it moves down the track. See you there!
Tuesday meetings often turn into training night at the Makerspace. So many members come the the weekly meeting that it can be easy to find something new to learn. Last week was no exception when Pete gave an intro to screen printing.
It seemed like a straight forward process and I would encourage people who want to try making a t-shirt to email Pete to get checked out on the machine.
After walking the class through the basics of preparing the silk with the design. Pete set up an example print and let his small class of makers give it a try.
This week I attempted the first test of the chocolate printer cooling system. The cooling system is intended to solidify the chocolate just after it leaves the extruder nozzle so that by the time the next layer is started it will have a solid layer to sit on. The cooling system consists of a centrifugal blower with a brushless DC motor blowing room air into a styrofoam cooler containing a block of dry ice. The air passes over the dry ice and gets chilled as the dry ice sublimates directly into very cold CO2 gas. The chilled air and CO2 mixture exit the box through a port with a hose that will ultimately blow the cold air on the chocolate. At least, that’s how it is supposed to work. It blows air at -12C as measured via a thermocouple, but unfortunately, the air exit port ices up in about 2 minutes and blocks the air flow.
There are many possible solutions. I can add a heater to the exit port to prevent formation of ice, or dry the air going into the box using a dessicant cannister or maybe just use water ice instead of dry ice if the higher temperature will still cool the chocolate adequately. Maybe using an old miniature freezer with an air hose coiled inside would do the job. It would be really interesting if I could use the waste heat from a freezer to keep the chocolate liquified and flowing. Back to the drawing board!
Chocolate printer progress continues. This week was devoted to the print cooling system. The chocolate will come out the extruder nozzle in a semi-molten state. It needs to solidify by the time the next layer of chocolate gets deposited on it, and I’d prefer it doesn’t drip or sag, so it needs to be chilled right after extrusion. The current plan is to blow chilled air over the chocolate just after it leaves the extruder. The chilled air will come from a foam insulated box containing a block of dry ice. There will be a blower pushing air into the box and a hose delivering the chilled air/CO2 to the print.
A couple weeks ago I got a blower from American Science and Surplus and this week I got it running by using a model airplane ESC and servo tester to drive its brushless DC motor. It appears to be capable of blowing much more air than I’ll need. There are many unknowns yet to test. How much chilled air/CO2 will it take to solidify the chocolate after it leaves the extruder? How long will a block of dry ice last when used this way? Will ice build-up inside the chiller box adversely affect its performance?
I designed and printed three parts for this system- a mount to attach the blower to a foam box up to 1.5″ thick, a hose coupler to allow delivery of the chilled air/CO2 to the print, and a hole saw to cut holes to fit the other two parts. The printed parts fit as if they were designed for the job!
3D printed hole saw
Hose connected to hose coupler
Hose coupler parts
Blower mount for air chiller box
Join us for The Greatest Show (& Tell) on Earth at Wisconsin State Faire Park September 24th & 25th, 2016. Admission is free. A joint presentation by Milwaukee Makerspace and the Betty Brinn Children's Museum.
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