Knowledge Bank

MDM is an observatory in Arizona that hosts the Hiltner 2.4 m Telescope and the McGraw-Hill 1.3 m Telescope. Both telescopes carry a sub-assembly called the Multiple Instrument System (MIS) which provides a universal mount for focal plane instruments like imagers and spectrographs. The MIS consists of a finder, a guider, and a 12-Position Filter Wheel. The 12-Position Filter Wheel is an electromechanical system that selects the photometric filter to be placed into the telescope focal plane. This filter wheel has been used on most clear nights on the 1.3 m telescope for nearly 20 years. Several issues have arisen over its 20-year service life that need to be addressed to improve the filter wheel's robustness, usefulness, and longevity. Through redesign, simulation, and experimentation of electrical and mechanical systems, a refurbished filter wheel is being built. This updated filter wheel will meet the performance requirements of the observatory and support facility and third-party instruments, for many years to come.