Aircraft instrument hole reducer adapter

thingiverse

In general aviation aircraft, the round instruments mounted in cockpit panels are generally one of two common sizes: 2-1/4" (57mm) and 3-1/8" (80mm). MS33638 This thing is an adapter plate that allows you to utilize a 2-1/4" instrument in an aircraft panel hole that was designed to fit a 3-1/8" instrument. The design is made so that the surface of the adapter should be able to sit flush with the surrounding panel, however the actual 2-1/4" instrument will be slightly recessed behind the inner cutout of the adapter. Traditionally purchased adapters of this style would normally have an inner overhang so that the 2-1/4" instrument can sit closer to the adapter's face, but this would unfortunately be more difficult to print. Print Settings Notes: It's recommended that you print using ABS (not PLA), since the cockpit environment can get very hot and will affect the strength and shape of PLA. Post-Printing Mount using MS35214-27, 6-32 Instrument mounting screws or equivalent. You may need to use instrument mounting nuts (A8943-632-493), Tinnerman nuts, or 6-32 machine nuts if the screw fit is not secure enough.