40 cm f4.0
In June 2007 I had finished a pyrex mirror with a focal ratio of 4.9.The mirror had a thickness of 35 mm. Probably Jilles Eindhoven from Buurse (NL) had made it from an 80 mm thick disk. The mirror ended…
Adventures of Frans van Schaik
Adventures of Frans van Schaik
In June 2007 I had finished a pyrex mirror with a focal ratio of 4.9.The mirror had a thickness of 35 mm. Probably Jilles Eindhoven from Buurse (NL) had made it from an 80 mm thick disk. The mirror ended…
25 cm f4.5 mirror This mirror will be used in a grab and go dobson. I have already a 255 mm x42 mm pyrex disk that has a f3 curve in it The sagitta has to be brought back from…
15 dec 2014 I bought a 56 x 3.1 cm Suprax borosilicate disk from Stathis Kafalis in Munchen for about 800 euro. It was made by Schott. The mirror ( if it succeeds) will be the replacement of the very…
30 cm f4.9 mirror December 2017 The mirror is made from an already existing 50 mm thick pyrex miror that is f6 Sagitta is ca 2.9 mm over 290 mm diameter. It will have to be about 3.5 mm Excavating…
44 cm f3.4 July 2016 The idea started when I thought of a large deepsky telescope that would fit in one piece in my Renault kangoo van. Jilles Eindhoven in Buurse had a 45 cm 34 mm thick pyrex disk…
30 cm f4.4 mirror Sept 3, 2016 I bought a 300x 25 mm borofloat disk from Stathis Kafalis in Munchen-Germany Cost e 132 + e 13 for grinding the backside flat with C320 Wanted focal length : about 135 cm…
GRINDING January 2000 The pyrex disc (205x 20mm) is hollowed out to approx. f4.5 by J.Eindhoven in Haaksbergen. I cast a 4 cm thick plaster disk on it and after 1 week drying I glued 19x19x2 mm porcelain tiles…
60 CM MIRROR This one has always been a dream for me. But the prices of the glass!! When I started thinking about a 60 cm, the price of a disk was ca 5000 dollar.. Suddenly, I heard about pyrex…
47 cm f3.9 mirror The suprax disk measuring 480×40 mm was purchased in 1998 and converted to a f5.1 mirror in 2004. After some years I decided to convert it to a mirror with shorter focal length, just…