Rabbit Hole

Rabbit Hole

Team Topic - Deconstruct: Zombie Apocalypse

The Rabbit Hole is a global hackerspace, but also a brick-and-mortar in Rochester, MN that consists of a group of engineers and tinkerers who work at Mayo Clinic and IBM.  Each of us have a plethora of projects in progress and we love helping others with their's!  We encourage everyone to jump with us into the rabbit hole to expand and enhance their projects!

Rabbit Hole Video:

Rabbit Hole updates:

Rabbit Hole – Post Script

Posted on: March 1, 2013

We’re still cleaning up the Rabbit Hole from all of the excitement – and thanks to inspiration from The Deconstruction, we’re actually reverse engineering the circuit of one of the projects (Solar Lantern) for a Learning-to-Solder class we’re hoping to host in the upcoming future:

Solar  Lantern2

The fun never stops!!

The group also agrees that the Recyclotron would be much improved with a laser….in whatever form it comes ;)

Rabbit Hole – Final Video – Final Post – Awesome Links!

Posted on: February 25, 2013


Final video: http://www.youtube.com/watch?v=eCHQqMoU4Jg

Wow. Over 48 hours later and I think our team is getting hackathon withdrawals!  We’re putting our update posts on the tymkrs blog and if you didn’t get a chance to follow it in real time, you can see the posts now!  So here are some links for you to follow if you’d like to get to know the Rabbit Hole better, or if you have questions about the projects.  Go Team Rabbit Hole!:

Twitter: http://twitter.com/tymkrs

Blog: http://tymkrs.tumblr.com

IRC Chat: https://qwebirc.afternet.org/?channels=tymkrs

Youtube: http://youtube.com/whisk0r (We’ll have some outtakes and extra footage from the 48 hours)

Rabbit Hole Site: http://tymkrs.com/rabbithole

Zombie Music: http://soundcloud.com/tymkrs (Played for watchers during the stream :))

Instructable Documentation!: http://www.instructables.com/id/Deconstruction-Rabbit-Hole-Phase-1/

Rabbit Hole – Extra Information on Can Crusher

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How the Can Crusher Counts Cans

Modern garage door openers are required to have a sensor beam that prevents the garage door from closing when the opening of the garage is blocked. We thought it would be great to reuse these sensors as a fun way to count how many cans have been crushed, thereby allowing us to estimate how many millions of dollars the recycling center will pay us. The basic plan is to read the sensor output through use of an Arduino Micro controller system, the Arduino will also keep the count and output the count on the digital display of a reclaimed old dartboard.

The garage door sensors are tricky in that they are manufactured to be hard to defeat essentially by adding a pulse in the output. To understand how this works a good video is found here http://youtu.be/GbmufXgpl14 The sensors we had were just like the ones in the video, the transmitter has a yellow LED when powered and the reciever has a Green LED when aligned. We simply tap in to the wires going to the green LED on the receiver. Thus when a can comes through the loader, it breaks the beam and turns off the signal being sent to the arduino.

The 7-segment chips from the dartboard were easy to remove thanks to use of a “solder sucker”, basically melting the solder and vacuuming it up. Problem is, each of these chips require 7 digital output ports from the Arduino …so if we power 2 digits, we would use up all our output ports. Luckily at the Rabbit Hole we were able to obtain 2 74HC595 shiftout shift register chips. Shift Register chips allow you to control a 7 segment with only 3 output ports. See this tutorial for details http://arduino.cc/en/Tutorial/ShiftOut

Now with extra ports available we were able to use them to control fun this such as, LED lights, the Dancing Toy Robot and even play sounds from a reclaimed sound effects board. We did find that the USB Robot required too much power to be powered straight from the Arudino so we connected to a relay switch from the Arduino. In the finished product, the Dancing Robot and “Sound and Light show” happen every time twelve cans have been crushed (show runs until next can is crushed).

Rabbit Hole – Extra Information on Bike Trailer Assembly

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  • 2x 1/2″ “black” pipe nipples 6″ long
  • 2x 3/4″ “black” pipe nipples 3″ long
  • 2x 1/4″-20 bolts 1.5″ long
  • 2x 1/4″-20 nylock nuts


  • Chuck the 1/2″ plack pipe nipple in a lathe with 5″ sticking out.
  • Boar the center of the pipe out to just under 5/8″. The pipe ID is 5/8″ or just over but there is a weld seam that needs to be cut down to fit properly.
  • Next turn the outside diameter down to 0.785″ (or 0.005″ under the ID of your wheel bearings) for a length of 3.5″
  • Cut off the pipe nipple to 4″ long.
  • repeat the above steps for the second 1/2″ pipe.
  • Next cut 2 rings out of the 3/4″ pipe 1/2″ wide.


  • The 1/2″ pipe should be a slip to pound fit over the 5/8″ axle.
  • Install one 1/2″ pipe shim with the “shoulder” in. Pound on till non shoulder end is flush with the end of the rod.
  • Next install the axle though the 5/8″ holes in the PVC T -> PVC axle tube -> second PVC T.
  • Install the second pipe shim again with the “shoulder” in (180 deg from the other end of the axles). Push the shim on until it is tight against the PVC Ts and the axle cannot float sideways in the PVC frame.
  • Next install the wheels on both pipe shims until the inside bearing is flush against the shoulder on the pipe shim.
  • Install the 3/4″ pipe rings so they are flush against the outside wheel bearing.
  • Finally drill a clearance hole for the 1/4″-20 bolt all the way through the 3/4″ ring -> 1/2″ pipe shim -> 5/8″ axle -> 1/2″ pipe shim -> 3/4″ ring. Install the 1/4″-20 bolt and nylock nut.

Rabbit Hole – Parts List!

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Parts list for The Recyclotron Can/Brain Crusher and Zombie Warning System:
Main Can Crusher Portion:
  • 2 ~1985 Sears Craftsman pneumatic snow-blower tires
  • 1 used Chamberlin 1/2 HP Garage door opener
  • 1 3/4″ by 4′ stock steel rod from Fleet Farm
  • 1 3′ chunk of 3″ ID PVC
  • Misc pile of reclaimed 2x4x4′
  • Misc screws and carriage bolts
  • 1 standard 3-way light switch so motor can go forward and backward
  • Chain from garage door opener
  • Rear 7 speed cassette (welded to steel rod) from a donated bicycle
Bonus Electronics:
  • 1 set of garagedoor opener sensors and wires
  • 1 Arduino Uno, reads door sensors display the count of cans crushed, and control the robot and sound effects
  • 1 Sportcraft electric dartboard deconstructed (or scavenged) for the electronic components including 7 segment LEDs and sound board. ($2.50 from Goodwill)
  • 1 broken usb powered dancing robot (arduino causes it to dance on every 12th can)
  • 1 breadboard
  • Misc transistors, resistors, LEDs, 2 74HC595 shiftregisters and 1 relay
  • 1 rail section from the garage door to hold the poster-board with breadboard/arduino mounted on it
  • Discarded power adapters (wall-warts) to power electrical components
  • Glue, zip-ties, solder, blood, sweat and duct tape
  • Only paid for 2 items, the axle was $7.99 and the dartboard was $2.50.
Parts list for The Foraging Bike Trailer:
  • 2” PVC scrap pipe.
  • Misc. PVC joints
  • 50′ nylon rope.  $1.99
  • 2 donated 20” bicycle tires
  • 5/8” steel rod axle
  • Shims to match axle to bicycle bearings
  • lock collars to hold wheels in place
  • 1 plastic tub
  • 3 flat bungee cords
  • Misc. bolts, nuts, and washers
  • 1 bicycle LED blinky light
Parts list for The Solar Powered Lantern:
  • 1×2″x8′ wood stock, plywood scraps
  • Broken solar lantern circuitry from garden lamp
  • Paper – chinese painting paper/rice paper or newspaper if you want
  • Screws, glue, nails

Rabbit Hole – 47-48 hours – DONE!

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Whattttt – won’t be long before we close up this 48 hour shop!

Project Updates/Current Status:

Bike Trailer [Done!]


Solar Powered Lantern [Done!]


Automatic Can Crusher

IMG_1964 IMG_1965 IMG_1966


  • Tim, Matt, Will and Peter have put together the epic can crusher – RECYCLOTRON – complete with dancing robot!

Rabbit Hole – 46 hours in

Posted on: February 24, 2013

46 hours in!   Wheee!  Tune into our show and tell – somewhere between 7-8pm CST :).  For adless streaming: http://tymkrs.com/videodesk – select Toymaker Television on the right drop down menu.  And to join in chatting (we can see it in the shop and respond instantaneously!) – https://qwebirc.afternet.org/?channels=tymkrs

Project Updates/Current Status:

Bike Trailer [Done!]


Solar Powered Lantern [Done!]


Automatic Can Crusher

IMG_1960 IMG_1961


  • Tim, Matt, and Peter have the can counter set up and are seeing if they have enough time to include a dancing robot!  We all need dancing robots.

Rabbit Hole – Zombie Apocalypse Deconstruction!

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Rationale for choosing the theme of “Zombie Apocalypse”:

One day, the undead will rise and come for all of us.  Instead of making silly decisions like splitting up the team or going off for resources alone, we can prep now!  Our projects were chosen to fulfill certain purposes:

We have the recyclotron which can both be used to crush cans and – if given a chance – act as a projectile launcher!  Or if the launcher portion doesn’t work, we can just use it brute force!

The bike trailer will be highly useful because bikes are not only light and durable, but don’t require anything but your two legs!  The trailer will let us lug around the recyclotron and lanterns.

The solar power lantern is perfect to keep people’s morale up even when the lights go down.  And it doesn’t even require anything but natural light!

Rabbit Hole – The Team

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Every awesome event has an awesome team – and here at the Rabbit Hole – we’ve got folks who we know could survive the INEVITABLE zombie apocalypse :).  Here’re some of their body parts!

Matt – “Bruzer” – Known as “The Punisher Guy” by the IRC following our Decon project, he does software, hardware, woodware, and everything in between!


Tim – “Can Crusher” – The Recyclotron was his idea and baby :).  Should be known as the food provider since he picked up food for us a bunch of times and even helped jumpstart a car!


Jon – “The bolt spiller” – Jon’s bike trailer was the subject of much discussion and hardware store trips!  But he also spills bolts all over the place :D


Peter – “The ‘What are you DOING’ guy?” & “Is this safe??…” – A brilliant EE who we found entangled in hundreds of wires at any given time of the project.  Need a circuit to work? He’s your man.


Will – “The camo shirt guy” – He got the foosball table up and playable and helped out with the projects, thanks man!


Ken – “The beekeeping laser guy” – He keeps bees and works on lasers for a living!  Crazy!  Also solved all problems with the electronics of the solar-powered lantern – thanks!!


John V. – “The hammer dude” – Also from the Rochester area and saw a link to the Decon projects and came over on a whim!  Helped with the solar lantern – thanks!

Whisker – “Whisker” – The one who set up our streaming, chat, and net system = crucial.


Addie – According to the internets I’m “tokengirl” – Hah.  Always wanted to make a solar lantern and a japanese style lantern too – now we have both in one!  Also into chinese painting!


And *drumroll*

THE INTERNETS :)  We have to thank the Tymkrs IRC for teasing us, encouraging us, helping us, and being the awesome global portion of the team!  WooHoo Internets!


Rabbit Hole – 44 hours in

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44 hours in!   We’re coming down to the last hours!  We’ll be trying to do our show and tell somewhere between 7-8pm CST :).  For adless streaming: http://tymkrs.com/videodesk – select Toymaker Television on the right drop down menu.  And to join in chatting (we can see it in the shop and respond instantaneously!) – https://qwebirc.afternet.org/?channels=tymkrs

Project Updates/Current Status:

Bike Trailer [Done!]


  • I think we’re done with this project!  If we get ambitious we might add LEDs but for now, woohoo!

Solar Powered Lantern [Done!]


Automatic Can Crusher

IMG_1947 IMG_1948

  • Tim and Matt are still working on the code and I think getting digit 9 to come up :D Learning Arduino programming on the fly!  Peter’s working on getting the IR sensors to work properly so we can get can counting set up.