More aperture is better. I've started to build a 240 mm Newtonian with some mirror blanks from Tammilasi and knowledgeable help and grinding materials from Teknofokus.
The first task was to grind the 240 mm diameter (40 mm thick) borosilicate mirror blanks flat on each side. This took around 1.5 hours per side using 60-grit silicon carbide and grinding against a flat steel plate.
1. Comment by anders
30/Jul/2008 at 21:08
I'll try to blog about updates to the telescope project, and also post some pics and thoughts to the forums:
Astronetti, in Finnish:
http://foorumi.avaruus.fi/index.php?topic=2784.0
Cloudynights (probably the largest astronomy forum out there)
http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/2550576/page/0/view/collapsed/sb/5/o/all/fpart/1
2. Pingback by Bookmarks about Build
20/Oct/2008 at 18:30
[...] - bookmarked by 1 members originally found by engage11 on 2008-10-06 Starting to build a 240mm Newtonian http://www.anderswallin.net/2008/07/starting-to-build-a-240mm-newtonian/ - bookmarked by 2 members [...]
3. Pingback by anderswallin.net › Building a Telescope, a drama in 21 Acts
13/Dec/2011 at 14:04
[...] Act 1 (2008 July 22): In which the Builders acquire the Glass and first smell the Carborundum. [...]