The first step was pondering various designs. Being an electronics junkee my first though was a couple big 7 segment displays. with LED's. I have a near limitless supply of 1/4" OSB and my head was already a buzz making all the little cell dividers and strips of LED's and dropping resistors that looked like HO train track to fill the segments in. Perhaps I will try this someday, but I bailed on this for a few reasons. The two big reasons is it would have to be super bright to be easily readable on a bright winter day with the sun out and snow on the ground. The second is that would require power and we don't want cords or cables running around. Trip hazards. Going rechargeable puts the onus of having someone responsible for charging it before each use. Batteries would be an ongoing expense.. Sadly, I started to think the electrics might not be the best way to go.
The next thought was to make segments on my 3D printer that could be manually rotated or flipped like a flip dot or flip segment display, but manually flipped This would limit the size of the digits to about 8" wide , the width of my 3D printers bed, Not bad really. At first I had thought about making 3D printed "corners" for the segments to rotate in. Than I thought of an all 3D printed plastic frame. I soon decided that he segments could fit in a wooden frame as my CAD skills are not up to designing a multi part snap together 3D printed plastic frame. I really liked this idea. The fly in the ointment with this one was the large amount of 3D printing. I should be able to crank out at least 4 of the segments at a time as they would fit on my printers bed, but I never do that well. I can do one at a time all day and night (and that is what one segment would pretty much take to print..) but if I queue up more without fail one will start to peel up until the head hits it and pulls it off and it crashes into the next one knocking that off, right on down the line. In the unlikely event one or two survive, the steppers have both missed steps and the printing of the remaining pieces is offset. So I bailed on this idea because of the amount of printing time and it being the summer (lots of more fun things to be doing than babysitting the 3D printer).
Moving along, the next thought was to use PVC pipe for the segments and rotate it instead of flip it, At first I thought about making 3D printed ball ends for the PVC that would fit into 3D printed sockets. Again on a wooden frame. After thinking about it, the 3D printing seemed to be expensive and slow, plus my limited CAD skills would frustrate me. I can CAD things but it takes longer to draw up the part in CAD than is takes me to make it out of wood.
The next idea was PVC pipe and off the shelf PVC fittings. I had a few big pieces of 1/2" PVC pipe and all of the fittings were under a half buck a pop at the local hardware store, and even less at one of the big box stores in town. The only fly in the ointment with these was the fittings for the center horizontal segment. You can buy PVC furniture fittings that are T's with one vertical sprew coming out of them, but they are expensive. I opted to just use Tee's to hold the center segments and if necessary I could glue shims under them.
My segments are about 9" end to end made out of 1/2" PVC that I had kicking around. I cut them out on my chop saw with a stop so I could crank them out quickly and consistently.
I sanded the pvc pieces down prior to painting them. You can just use sand paper. I built a jig on my wood lathe to make it easier. It is an oak rod. One end fits in my drill and the other end slowly tapers from skinny to thick and you can stick the PVC on it and spin it with the drill. ...Read more »