• The Seed of an Idea

    sjm430604/26/2019 at 14:44 0 comments

    So I'm no stranger to electromechanical displays. I've built one just a few months ago using flip 7 segment modules from Alpha Zeta. However when I first saw the super expensive Devon Tread watches I knew I eventually had to make a cheap, easy to make DIY version. A few years went by and I never got around to it. Then I saw hackaday was throwing a flexible pcb contest ... 1 and 1 clicked together to make 2!

    Why not use the flex pcb as the actual display scroll containing whatever numbers, letters, or symbols I want?!?! And very simply on the rear side I can use the copper/stop layers to act as contacts/reflectors to allow the display to keep track of the current position. I know I could cheap out and use vinyl or some other material for the belt but having nice shiny flex would look very slick and I dont think anyone else is even crazy enough to have tried this before. I quickly threw together a pcb design and started thinking about how it would mechanically work. I had intended to ask my youtube sponsor to grant me free prototypes but it appears they don't do flex :-(. Ok well I guess I'll just have to pay out of pocket ... but when I went to see how much a flex pcb for just numbers 0-9 would cost (~$100 for just 5 pieces), the project was dead in the water.

    Here's hoping I can get some free flex pcbs to see if this crazy idea is viable and get a few prototypes built and running. I know this is probably not what the judges of the contest will have in mind for a flex pcb project, but I hope it counts. In the next log I'll outline with some hand drawn diagrams how I plan on handling driving the belt with a motor in as compact of a space as possible as well as accurately positioning the numbers and homing the display.

    Edit: Looks like the contest would only provide a voucher for 3 boards of up to 2 in^2 in size and the entrant would pay for the excess ... DOH ... looks like the board I've designed would more like 16.5 in^2 lol. Well I guess I'll leave this project in the contest as a submission illustrating creativity ending in insanity!