Open reflector lid cooler

This little project was the invention of foreign body ingress prevention into a Newtonian reflector OTA. Most newt scopes now come with a little blower fan mounted to the outside of the mirror cell, but for it to be effective this requires the lid at the top end to be removed while the fan runs for X amount of hours while the scope approaches ambient temp.

A drawback of this sort of simple mirror cooling system is the time the upright tube must stand outside with the apeture end open, and the amount of time the scope has the chance to accumulate dust and larger airborne particles that can to settle on the mirror, not desirable.

This idea features 12V computer casing fans mounted in the OTA lid to extract the warm air out of an scope without subjecting it to the flotsam in the passing atmosphere. Cooler air is drawn in from around the mirror cell end and sucked out via the fans at the top, extracting the warmer air generated by the OTA out the top through the scopes lid fans.

The pics best describe the idea, it seems to work fairly well.

by Steven McNelley