This year, I decided to KISS.  I ripped out all the guts, except for the Neopixel eyes. I decided that this year, I’m not going to have sound in the skull. Instead of the Uno, I went with an Adafruit Trinket, and used a UBEC (Universal Battery Eliminator Circuit) to drop the LIPO voltage from 7.4V -> 5V that the Trinket and Neopixels run at. Shown below is how everything is connected together, prices, and sources if you’d like to make your own! And here’s a video of what the eyes look like (sorry about the VVS!!)!

And failed miserably. Running at 18v (50% more than its rated voltage!), it was only drawing ~200mA, and could only lift 2-4 of the 7/16ths nuts I’d borrowed for use as ballast.

So my inner maker came boiling to the surface and yelled at me, “why not wind my own!?”…

I present to you, failure #2: The small, drill-wound electromagnet:

This magnet was made from 28ga wire, and also ran at about 18V. It didn’t pull much more current than the previous one, and was also only able to lift ~3-4 of the 7/16ths nuts. I remembered Tom had a GIANT SPOOL of copper in his area, so I asked if he minded if I used a bunch of it. It turned out to be 17ga! After searching the ‘space for the right core (initially, a bolt, as shown in the previous photo), I found a nice piece of 1/2″ bar stock, and a piece of PVC tubing that the bar fit into perfectly. Once again, the drill came out, and I wound a much larger electromagnet:

This guy means business! It metered out at about 2.3 ohms. I fired it up with the bench-top power supply in the electronics lab, which immediately went into current-limit mode. At 6V DC, it was drawing 2.75A! I brought it over to the pile of nuts and it picked up about 15 of them! SUCCESS! According to Ohm’s law, if I run it at 12V, it’s going to draw close to 5A of power.. But the resulting field should be even stronger!

The original plan was to wind the copper around the PVC, but I would it too tightly and wasn’t able to remove the PVC afterwards. Oops! There was some debate as to whether a U-shaped core would be best, so that’s what I worked towards. After some testing, I found that the U-shaped core didn’t help at all, so I had Dan help me turn the u-shape into an eye. This will make it easy to suspend from a string.

Here’s a comparison of the three magnets to give you an idea for size..

Stay tuned for more photos of the electromagnet crane build!

(Also, for the Monty Python fans.. working on this project made me feel a little like the King of Swamp Castle must’ve felt..)

MMMG

You can change the number of weeks’ worth of data it displays, by adding “&weeks=xx” to the URL, like this.  There’s a little bit of missing data here and there, which is why there are some skipped week numbers. Right now, I’ve collected approximately 25 weeks worth of data. This will only grow as MMS does, though! You might end up seeing this in the MMMPIS too!

Also, coming soon: A stand-alone executable version (for Windows) of the HMMDMMH!

EDIT: 2014 Week 26: After this was implemented we looked closer at the numbers and found an error. It has been corrected, hence the drop

I had recently started working with Arduino (after a failed run at Microchip’s PIC series of microcontrollers), and was making progress quickly.  I learned how to read infrared remote control codes, how to use an infrared motion sensor, and how to control servos. What I did not have, was a sense of direction as to where to go with all of this!

After listening to the Bay View Neighborhood Associate pitch their idea of MMS helping with the Pumpkin Pavilion, and listening to Royce Pipkins describe his idea of animatronic pumpkins singing along to a song, I was struck with my own idea: an animatronic skull.

Thus, it was born!

http://vimeo.com/55121596 <- Link to the video

I’ll post more details in a following post about how I built this guy. :)

Many thanks to Royce, Tom G., and Ed C. for their help on this project!