A few months ago, Hack A Day featured an ingenious hack called the Reverse Geocache Puzzle by a gentleman named Mikal Hart (please note that “Reverse Geocache Puzzle” is Mikal’s trademark – my unabashed clone of his project will hereafter be known as the Frustromantic Box). As soon as I saw it, I knew I had to build one. It took a lot longer than I thought it would, but I had the finished product ready in time for my wife’s Christmas present. She still hasn’t opened it, so I have to be a little cagey here.
I’ll describe this project in a series of posts. This post – the first – will go over the high-level design of the box.
The goal of the project is to produce a box that is locked from the inside and will only unlock itself at a specific location. The Frustromantic Box actually has two locks (a lid and a drawer) that can be toggled independently. Here’s the parts list:
- 5′ of cherry 1″x6″ for the sides of the box
- 5′ of cherry 1″x3″ for the lid of the box
- 1/4 sheet (4’x2′) of 1/4″ birch veneer plywood. This is more than necessary, but it was the smallest amount I could buy.
- Small can of Varathane Gel Stain (602 Cherry)
- Small can of Varathane Professional Clear Finish (Clear Gloss 900)
I bought all the above supplies from Windsor Plywood. If you’re a novice woodworker like me, I strongly recommend building a prototype out of pine first. I used a router, a mitre saw, a table saw, a biscuit joiner and a scroll saw to cut the various pieces to size. I used a couple of these speed clamps to assemble the pieces.
- Arduino Duemilanove
- Arduino Protoshield
- Mini Self-Adhesive Breadboard
- HD44780 LCD Display
- Icecube Light Pipe Switch
- Polulu Pushbutton Power Switch LV
- Full Rotation servo
- EM406A GPS Sensor
- Hitec HS-81 servo
- Panasonic PNA4602M IR Receiver
You can tell from the links, I ordered almost all the parts from Sparkfun. Those guys are great. However, the Light Pipe switch was a real pain to use. If I were to do it again I think I’d order this pushbutton switch from Seeedstudio (also a great place) which is the same one that Mikal used in his project. The HS-81 servo I picked up from a local hobby store when I decided to add a locking drawer to the box. The IR Receiver is used to activate the “back door”, I just had it lying around from an earlier project. The full rotation servo is unnecessary and makes the Arduino software a little more complicated than necessary. In hindsight I probably should’ve got this servo instead.
- 1/4″ eyelets (I got a pack of these from Home Depot)
- 1′ threaded pushrod + clevises (also from the local hobby shop)
- 1/4″ dowel (Home Depot)
- Ikea MOLGER toiletry container thingy
- Ikea BJURÖN plant container thingy
- 2’x2′ velvety cloth (I’ve no idea what the proper name for this textile is, I used it to cover the bottom of the box)
- Lee Valley Concealed Lid Hinges (this was a bad idea)
The eyelet holes should be just big enough to accomodate the pushrod, with a little bit of wiggle room. We will transform the Ikea bits into a crude drawer. I recommend against using the concealed lid hinges. My experience with those hinges is, you can either have the lid flush with the top of the box when closed, or you can have the lid open a full 90 degrees. You can’t have both. If I were to do it over again, I’d just use some nice stainless steel hinges and chisel out whatever notches are necessary.
I didn’t take any pictures of the build process, so I’ll show that using some SketchUp models. But here are a few shots of the finished product:
Continue to Part 2: Assembly