48-Well Magnetic Separator

I'm running a somewhat high-throughput experiment on paramagnetic beads, and figured a 96-well-compatible magnet would be useful. Commercial versions (like [this one from Thermo](https://www.thermofisher.com/order/catalog/product/AM10027)) can run into the $400 range, which was far more than I was willing to pay for. Turns out, you can do this in a 48-well plate format for about $15 in magnets along with a bit of filament.

It's hard to see the pull-down pattern in the pictures, but Dynabead M280s will pull up on the sides of the wells cleanly and rapidly, even at 10uL.

I modeled this on Tinkercad, so feel free to remix either here or [there](https://tinkercad.com/things/euvsglFyqaA).