Designing and Testing of an Optical Tube Assembly for Commercial-Grade Reflector Telescopes

Abstract

Reflector telescope is the most popular telescopic design among the astronomy community due to its simple structure, accuracy, and affordability. Although the quality is excellent, the optics of a reflector telescope must be able to align precisely by a rigid but alterable mechanism for accurate performance. In this study, a commercial-grade optical tube assembly (OTA) was designed for small-scale Newtonian reflector telescopes. Here, the optical system was designed using standard equations and calculations based on the dimensions and optical properties of a 0.0974 m f/6.5 parabolic primary mirror, which has a thickness of 0.012 m. The accuracy of the designed optical system was tested using a raytracing simulation. Hardware designs of accessories of the optical tube assembly were drawn using a Computer Aided Design software. In this instance, emphasis was placed on characteristics including strength, user-friendliness, light weightiness and attractiveness that a commercial-grade optical tube assembly should possess. A bunch of simulations were undertaken to evaluate the properties and optimize the designs. The drop test was used to evaluate the strength of the designed accessories and each of their sub-component. Dimensions of each component were optimized to keep their light weightiness and cost-effectiveness while sustaining their strength. Furthermore, deformations that can occur on mirror holders due to the weights of mirrors were analyzed by simulating a buckling analysis. Simulations were repeated by assigning a variety of materials, including acrylonitrile butadiene styrene (ABS) plastic, polylactic acid (PLA) plastic, stainless steel, and iron for the designed components to identify the most appropriate material for each subcomponent. Finally it was confirmed that the designed optical tube assembly is appropriate to use in commercial-grade reflector telescopes according to the test results.