View Single Post
  #4  
Old 11-10-2011, 07:29 AM
sopticals's Avatar
sopticals (Stephen)
Registered User

sopticals is offline
 
Join Date: Jun 2010
Location: Oamaru, New Zealand.
Posts: 226
Rod-Great stuff. My first project was a 7" EQ Newt back around 1962 as a 17 year old,(no Dobsonian options in those days).Even with the f7.5 mirror the scope was a monster with its 1/8" alluminium tube and massive EQ mount (my own design) made of cast iron having 1" bright steel shafts, a 3" pier (boiler pipe) with "hens foot" base also 3" pipe. The thing must have weighed 100kg. However it performed for me, being able to use out to 40-50x per inch of aperture.Compared to the 3" reflector (Japanese origin) bought from a local camera shop, its performance was the difference between night and day. In those days in NZ with the import restictions and such it was almost impossible to buy a reflecting telescope of greater than 3" or 4.25". The only 6" and 8" (biggies in those days) were home made. Now days biggies start at around 14", and again the only affordable way to go (if your budget is limited), is to fabricate ones own from the ground up. I figure that in real money terms that my current 25" Dob project will cost less (thanks to the brilliance of John Dobson and his simple concept), and actually weigh less than my original 7" Newtonian. With all the information available online its as easy to grind a 20"+ scope today as it would have been an 8" 50 years ago.
Reply With Quote