Analogue King Of the Hill Timer for Combat Tagging Sports

As I am not versed in the machine language, I have been forced to come up with an analogue solution to a gameplay aid I've wanted for a long time. Historically, to play king of the hill rounds in Nerf battles, I would use two (or more) moderators with stopwatches to keep track of who had the hill longer. No more! This print - and componentry - should allow me to run KoTH games - indeed, many point-holding games - nearly moderator-free. It's a pretty easy print, support free, but you need some parts:

• Standard clockwork mechanisms. I used something like these for ~$2/each. You need two per timer and they need second hands to be useful. I don't use the hour hands, and just cut the hands down to the size/shape I wanted with a standard scissors.

• A three-way switch. On-off-on. Mine are pretty small rocker switches I found on amazon for ~$1/ea, nothing in the design prevents you using two two-way switches or another kind of switch or button. Ideally, you want pressing it to start one clock and stop the other, which the on-off-on does well.

• Wire. I have stranded, but solid core 18-24ga would likely be better.

• A 4x6 index card box. I found nice clear ones at walmart for $4 each.

• A AA battery.

• Optionally, two printed dummy batteries to make wiring easier. You will run wires to the ends of these, not through them, because we need flow to be interruptible.

To assemble, print the file and the clock face sheet (or use your own). Mount the clock mechanisms in the 3d print, cut out and place the clock faces on the print, screw the shaft nut down to keep the mechs and clock faces in place. Add the minute and second hands, cut to length - they must be shorter than the print. Wrap two wires around the negative side of the battery tray and into each clock's battery contact (or use a dummy to hold them in place). Insert the switch to the box - you'll need to cut a hole to fit the switch you have. Wrap one wire around the positive contact and to the center of your on-off-on switch. Wrap two other wires around the remaining contacts on your switch and either clock mech's positive contact. Verify the clock you expect to activate does when the switch is pressed - mine needed to be wired opposite to work the way I wanted it to. Insert the printed, wired, assembly into your box - you may find it ideal to create a step inside the box to keep the clock in place, I plan to use cardboard strips wrapped around the inside. Cover it up and you're good to go!

Since these clock mechs are designed to run for months at a time and we're turning them off entirely, I expect that installing the AA will last for an entire season of games, if not years worth or until the AA's shelf-life expires.

You're welcome to use them in your games or print for friends. Contact me (preferably on discord, etsy, or on reddit) if you wish to use them commercially, but TBH it'll be hard to sell for less than a commercial chess timer.