As a personal project, I decided to make a clock using some spare parts I had lying around. My idea: to make a clock where the hands were represented by a small laser pointer. You could put it on a wall and have the laser dot travel along the ceiling, walls, and floor, or you could tilt it back against the wall and have it traveling in a circle like a normal clock. I printed out the numbers 1-12 as black wall decals to place around my room to line up with the laser’s path.
This is a work in progress; I’m currently revising the original design to use a new, smaller red laser card.
Since I’m using parts sitting around my workbench, my clock module is actually a Quartz crystal clock. Quartz crystals are cheap and useful for keeping track of time, but clocks that use quartz crystals usually don’t have a lot of torque available to turn the hands. This particular clock uses plastic gears, and originally came with very thin plastic hands. This is why I’m currently revising the design; the original laser pointer component was large and heavy, making it too difficult to move. No point in having a laser clock if it can’t move the hands past 6!
There are some other complications with the design that make it a challenging project: If the laser card is attached to the gears that are moving the hands, then where do I wire the laser? The leads on the back are going to be constantly moving. They come with wires coming off of the leads, but attaching them anywhere trivial will just mean that they wrap, twist, and tangle as the days pass, and eventually something will break. I was considering feeding the wires through the clock module by passing them through the hole that has the axis of the second, minute, and hour gears, but thanks to how tightly their packed, there’s no good way of getting the wire through there (thanks a bunch, DFM principles). I thankfully was gifted a little jar of conductive paint, and my current plan is to paint a circular area that the wire can rest in. This will of course require making sure that the wire is always in contact.