When I heard about the Absurd iPhone Accessory Contest, I knew I had to participate. My first entry, a Voltron iPad was thrown together pretty quickly and would be near impossible to print out on my makerbot cupcake’s modest build platform. I really wanted to submit an entry that I could actually print and that was a bit more interactive than a simple case. That was about 2 weeks ago, and I’ve been working on something ever since.
I’ve always wanted to build The Most Useless Machine Ever, so I thought – why not combine it with an iPhone to create The Most Useless iPhone Case Ever? It turned out to be a pretty challenging project.
The typical “Most Useless Machine Ever” is many times the size of an iPhone, so the first thing I set out to do is find the smallest parts I could. The bill of materials for this project looks like this:
- Battery case
- DPDT Toggle Switch
- SPDT Microswitch
Luckily I had all of these parts lying around the house in some form or another. The parts that were a real challenge to find were a motor and gearbox strong enough to flip the toggle switch but small enough to fit in a fairly large iPhone case. I remembered I had an old Creative Webcam in the junk pile that had pan/tilt functionality. After taking it apart I had two small gearboxes with the stepper motors the size of a peanut. It took a few hours to track down the information about them but eventually I was able to drive them via an arduino. Unfortunately, after all that work the steppers simply weren’t strong enough to flip either of the switches, so I had to find another solution. Of course, with an electronics hoarder like myself there’s always more broken electronics to look through, and I found just the right motor in a broken Canon Elph camera. A big benefit is the Canon’s lens motor is DC, so I don’t need a microcontroller to drive it. In fact, with a simple DC motor all of the functionality of the useless machine can be wired with no chips at all.
The real trouble came when even that motor didn’t seem to be strong enough to push the toggle switch over. I spent an embarrassingly long time tracking down easier to flip toggle switches before I realized that I needed More Power (insert Tim the Toolman Taylor grunt here). I had been using two AA batteries which just didn’t give the motor enough torque to flip the switch. I changed over to a 4xAA case and we were in business! Unfortunately everything has its price – another 10mm to the thickness of the case with the new battery holder.
After getting all of the parts, I set out to design the case via pencil and paper, then in the programmer’s 3D modeler of choice: OpenSCAD.
Aside from the electrical components, everything else is 3D printed, except for the toggle switch handle extension (my printer just couldn’t deliver anything small enough that would work well). I found the inside plastic piece from a mechanical pencil worked well, so I just used that.
It took a lot of revisions to get it right.
Anyways, I could go on for a long time about this case, but the details are pretty boring. It’s all done now just in time for the deadline of the contest. Everything would have went a lot quicker if I had a better 3D printer (hint hint to the judges…), although I do love my cupcake.
Check it out on thingiverse: The Most Useless iPhone Case Ever