Modular Magnetic Life Counter! 

I created a modular life counter so I can add as many wheels as I want! (bring on the life gain!!).  You can add as many wheels/hubs you desire to allow for as many number places you need.  The hubs fit pretty snugly and are ultimately held together axially by 6x2mm magnets. I glued the “left” side hub into the end cap because I didn't want the endcaps to be any thicker than necessary.  And come on, you gotta have at least ONE wheel so one permanent makes sense.

Around the outside of the hub radially are 3x3mm magnets (10 each hub).  In the wheel part itself, are more 3x3mm magnets to locate/click into place with the magnet locations on the hub.  I put holes in the model so you can put magnets in all 10 locations so the rotation stiffness is completely customizable. I have 3 installed in the video, I think 5 is satisfying as well.  Let me know if you put all 10 in you crazy savage! (you must wanna really muscle up to change that life total!)

I have a little rectangle on one side of the hub tabs to indicate which side is “up” when you put them together.  This alignment is necessary to get the numbers on the wheel to line up correctly.  I've marked the ones in the video with a black sharpie, but when I print it again I'll multicolor print that cutout so it's prettier. (I tried to make the geometry different so a defined “up” wouldn't matter but the 6 sided shape for the hub tabs made a good tight fit and more sides were loose and stupid)

all magnets were super glued in.  Fun story, I almost super glued a magnet to my teeth, I'm a big dumb animal.

When printing the hubs, I used PETG as a support interface material to the PLA model to make the supports easier to remove.  I think this will be pretty important as you're going to maybe struggle getting the supports out if you don't and the tolerance for the magnets is a little tight and if the surface is just bridged or you have support leftovers getting in the way you may have problems.

crappy resolution youtube video below of the life counter (sorry, free software has it's limits after all).