So far I’ve checked that the Arduino and a cut-down prototyping board with motor driver and accelerometer roughly inserted will squeeze into the tin with some room for a battery. However, the actual size I have to work with may shrink depending on what I do structurally to the tin. Consequently, I’m focusing first on getting some ideas down for the external structure.
To the drawing board, and the cans
To start with, I drew up a rough pencil and paper net of the arm shape for the drone. I’m hoping to use the closing lid as a fixing point; the arms themselves will attach to the lip of the tin with the lid closing over them to hold them in place.
Here’s my first net drawing and the can-prototype I made from it:
The first thing is that it would look better the other way up so I changed the position of the flaps on the net design. Secondly, I wanted to make it more proportional to the tin I’m using, as well as more angular, streamlined and less boxy. So revised, it looks like:
In both designs, the motor mounting used two strips folded round the motor with interlocking slits. It proved unreliable to gauge and cut by hand, even with the diameter of the motor calculated (see the MK I paper design above). Additionally, that method won’t work for more rugged materials such as thicker aluminium. As such, I thing leveraging the mounting screw holes is a better option.
I finally drew up the designs digitally and printed them off.
This allowed me to test if I got the measurements right for the motor mounting and to see how they’d look on the tin.
I’m happier with the motor mounting and I think thin sheet metal will be fine to use for the drone arm – 0.2-0.4mm aluminum should do and you can buy it at almost any DIY or craft shop. Taping the arms on revealed a few problems so I’ll redesign the way the arms attach to the tin:
- The arm and lid obstruct one another; the lid doesn’t close even with the flaps lengthened
- There would not be enough give in the lid to shut with flaps jammed in using a metal thickness of sufficient strength.
A more invasive attachment method may be required.