In a 5 refractor telescope is there really a difference between tube constructio - Printable Version +- ask aluminium Forum (https://www.askaluminium.com) +-- Forum: My Category (https://www.askaluminium.com/Forum-My-Category) +--- Forum: aluminium faq (https://www.askaluminium.com/Forum-aluminium-faq) +--- Thread: In a 5 refractor telescope is there really a difference between tube constructio (/Thread-In-a-5-refractor-telescope-is-there-really-a-difference-between-tube-constructio--34695)

In a 5 refractor telescope is there really a difference between tube constructio - Melindanema - 01-16-2020 The thermal coefficient of expansion in steel is half of what aluminum isSuch as at a given temp, if steel is 11, then aluminum is 23.1Is this really a concern in telescope tube design? I understand that aluminum is 5% lighter.Thermal expansion is only a concern if you are doing long-exposure astrophotography, where changing temperatures will require occasional refocusingEven so, most premium refractors use aluminum tubes, because it is lighter, easier to work, and doesn\'t rustAluminum also has an advantage in thermal conductivity - it is less prone than steel to differential thermal expansion.Other related question aluminum sheet aluminum products aluminum plate alloys aluminum aluminium strips aluminum strips aluminum strip aluminum foil aluminum supplier