Mirror 610 F3 meniscus
The manufacturing phases of a meniscus parabolic mirror 610 mm in diameter and 20 mm thick, focus 1770 mm with focal ratio of F3.
Rotating table for meniscus mirrors
A simple rotary table for working mirrors, homemade with some carpentry tools…
Centrifugal casting (spin casting) epoxy mold for convex core in collapsing refractory (slumping) for meniscus blank.
The escalation towards the amateur construction of ever more powerful Newtonian Dobsonian reflector telescopes (thanks to parabolic mirror lenses of ever larger diameter trying to contain their weight) it collides head-on with some technical problems that grow exponentially with respect to the benefits provided.
Making a Blank Meniscus 406 F3,7 on refractory plaster mold
I refer to the following Michael Davis Youtube video that I have seen with interest and attention, also thanks to the “lock-down” impediments, fortunately so far in good health, successive in these times of crown virus, also considering that the English language dialogues of the films, constitute in Italy an obstacle for all willing and maybe scratch glass