Changes

==Receiver System Update: Baby Black Box==

==Receiver System Update: Baby Black Box==

[[File:BBB_night_test.png|frame|right|Baby Black Box uses a Fresnel lens similar to System III]]

[[File:BBB_night_test.png|frame|right|Baby Black Box uses a Fresnel lens similar to System III]]

The latest OpComms receiver system, named ''Baby Black Box'' is an update of the older [[OpComms System III#Fresnel Lens|Fresnel lens receiver]].  The design goals for the update were three: (1) to decrease weight, so as to decrease strain on the motor, (2) complementarily, to decrease torque on the motor, particularly in the axis of altitude rotation, and (3) to more finely focus light into the photodetector system.

The latest OpComms receiver system, named ''Baby Black Box,'' is an update of the older [[OpComms System III#Fresnel Lens|Fresnel lens receiver]].  The design goals for the update were three: (1) to decrease weight, so as to decrease strain on the motor, (2) complementarily, to decrease torque on the motor, particularly in the axis of altitude rotation, and (3) to more finely focus light into the photodetector system.

The first two goals were addressed by purchasing a Fresnel lens with a slightly shorter focal length than the previous system, allowing the whole receiver to have a smaller depth, and by changing the format of the frame from a Duron (hardboard) cube to a pyramid structure composed of carbon fiber, plastic, and foamcore.  The carbon fiber framing provides the structural element for Baby Black Box, ensuring that the thin Fresnel lens is not under any external loads and therefore will not deform.  In addition, an effort was made to provide a mounting point calibrated to the center of mass of Baby Black Box, such that the torques were balanced about the axis of altitude rotation of the motorized mount.  Due to the pyramidal shape, this resulted in a reduction of torque about the horizontal axis as well.

The first two goals were addressed by purchasing a Fresnel lens with a slightly shorter focal length than the previous system, allowing the whole receiver to have a smaller depth, and by changing the format of the frame from a Duron (hardboard) cube to a pyramid structure composed of carbon fiber, plastic, and foamcore.  The carbon fiber framing provides the structural element for Baby Black Box, ensuring that the thin Fresnel lens is not under any external loads and therefore will not deform.  In addition, an effort was made to provide a mounting point calibrated to the center of mass of Baby Black Box, such that the torques were balanced about the axis of altitude rotation of the motorized mount.  Due to the pyramidal shape, this resulted in a reduction of torque about the horizontal axis as well.