To begin, I needed a rodent wheel. I chose the mouse wheel, because when I visited the pet store, the mice were running on the wheel while all the other rodents were busy sleeping.
Then I affixed magnets to the side of it. After significant trial and error, I used a shower drain that turned out to be the perfect size and affixed them with superglue. This is trickier than it seems because the magnets are powerful. Be careful because these magnets can pinch your fingers. I used 1/2″ Neodymium magnets from Amazing Magnets. but in retrospect, the 3/4″ magnets recommended in the article might provide more power. Once the magnets were on the drain-plate, I attached the drain-plate to the side of the wheel with more superglue and zipties.
I used sewing bobbins to wind my coils and they worked great. Once you get a coil all wound up, give it a coat of superglue to make it behave. I made 6 coils and went through three containers of superglue and two rolls of 30 gauge magnet wire on this project, so make sure to stock up!
I re-used the structural wire-rods being used as a base for the axle. I used a hot-glue gun to hold the coils in place. I used a bit of 2×4 left over from the workbench I made two weekends ago.
Now that I’m done with it, I want to add a bicycle computer to see how far Annika runs in a day and track her progress. I’m also planning on adding some ball bearings to make the wheel quieter. I tried adding some silicon dust lube, but it didn’t help. I’d also like to learn how to make a mouse-cam and give these mice a home on the web!