The first OSU 12-position filter wheel was developed for the Y4KCam project to equip the CTIO Yale 1m telescope for the SMARTS consortium.  Built in 2003, it was based on a radially-loaded cartridge-type 8-position filter wheel built to prototype mechanisms for the the MODS spectrographs for the LBT.  The first 12-position filter wheel was a student-led project that was deployed to CTIO Yale 1m telescope in 2004 and saw service until the Y4KCam system was retired in 2019.  This first filter wheel had a red-anodized electronics box cover that was decorated with a decal of OSU's athletic mascot Brutus Buckeye, and so it was thenceforth known as the "Buckeye Filter Wheel".

The success of the first filter wheel led to us building 2 more iterations for the MDM observatory: the first for the 1.3m telescope in 2007 and the second for the 2.4m Hitlner telescope in 2008.  They were intended to replace the aging and rapidly failing facility filter wheels on the MDM Multi-Instrument System (MIS) focal plane "top boxes" that all instruments at MDM use. Both remain in service to this date.  

All of the Buckeye filter wheels also gave us the opportunity to introduce new technologies to our instrument designs: use of turntable bearings, development/improvement of roller-detent kinematic docking systems, ethernet-addressable motor controllers, and inductive proximity sensors to replace physical microswitches.  Lessons learned from building these filter wheels led directly to improved wheel-type mechanisms for filter, slit, and disperser selection that were critical to the success of the later OSMOS, KOSMOS, and COSMOS spectrographs.  While humble filter wheels, they exemplify our doctrine of relentless prototyping and evolution of proven designs, and are milestones in our deep engineering heritage at the ISL.

The original Buckeye filter wheel was repatriated to OSU in 2020 after its retirement at CTIO, and it is being extensively upgraded to use new motor controllers and hardware drawing on our experience building the DESI unit spectrograph components, and in the spirit of the original, the upgrade was a student-led project.