Aluminum Telescope Tubes
We offer a complete line of aluminum telescope tubing for those who wish to construct their own tube assemblies. Aluminum, contrary to what some would have you believe, has far better thermal and mechanical properties when compared to fiberglass or cardboard. In open tube telescopes such as reflectors and Cassegrains, it is of the utmost importance that the instrument reach thermal equilibrium as rapidly as possible. In this respect aluminum, being a poor insulator, tracks with the outdoor ambient temperature much quicker than tubes of fiberglass or cardboard. Perhaps you may have noticed this effect when removing an aluminum baking pan from an oven. You'll notice how quickly it cools down. This same phenomena takes place as the sun sets and the outdoor ambient temperature drops.
In addition, Pyrex glass and aluminum tubing track each other more equally as the evening cools. Mechanically, aluminum has a modulus of elasticity from 2 to 5 times as great as fiberglass thereby providing superior strength and rigidity. This is important for maintaining optical alignment. It is no wonder why long focus refractors have always been constructed of aluminum.
When properly prepared, aluminum will take a beautiful finish and is also easily worked. To summarize, fiberglass is a wonderful material if you are constructing your own surfboard. Aluminum is for telescopes.
We can also supply aluminum tubes which incorporate a process that provides even greater rigidity at the 2 ends of the tube where it is required most. This process is called "rolling" and it is well worth the modest additional cost. We recommend it for all Newtonian tubes.