8 inch mirror being ground.

Just finished the rough grinding on an 8 inch mirror tonight. This is my first go at mirror making. It will be fun to see how it turns out. Took me about 6 hours total to rough grind an 8 inch (1.25inch thick) plate glass blank to a curve of F/6. I will spend tomorrow night cleaning up all of the rough carbo and then start the fine grinding on tuesday.

I'll keep some updates in here so that anyone thinking of doing this can learn by my mistakes. I know there'll be lots of them (mistakes that is).

I would be interested to know how things progress. Any chance of a materials and suppliers list?

James,

The easiest way to get the stuff you need, (Glass blanks, grinding grit, fine grinding grit, polishing compounds, polishing pitch etc) is to buy one of the kits from someone like galvoptics or beacon hill telescopes.

www.galvoptics.fsnet.co.uk/telescope1.htm
www.beaconhilltelescopes.mcmail.com/optical.html

These contain all of the optical items you need.

You should get this book;

How to Make a Telescope By Jean Texereau its the bible of mirror making.
www.amazon.co.uk/exec/obidos/ASIN/047185.../202-5797733-0333424

Ouch the price!!!! Dont buy it from amazon!!

Some other basic things you need is somewhere to grind comfortably, plastic bucket and lots of sponges, spray bottle, some jars for the powders. There are some other basic houshold things too.

Dave,
are you taking pictures as you go along? I think it would be neat if you did - this kind of process is rarely done by amataur astronomes anymore, all over the world. With the price of low-expansion glass having fallen considerably in the last 8 years or so, I woudl not be surprised if grinding started to pick up a bit!

I have an 8.5 inch blank at home I hope someday to grind. And I want to try a 10 or 12 nich someday too.

Keep some pictures of your adevntures in mirror grinding!



Seanie.

Very interesting... do keep us informed and as others have said please please take some photos as you go along.

Good luck!

Very interesting indeed!
How much harder would it be to grind a 10 or 16 inch mirror, would you need the arms of a wrestler to do it ??
Its all fine grinding the mirror, but how do you test it to see if its optically perfect, do you think you can get it 1/8 or 1/12 wave accurate ?? or is 1/4 wave a major feat ??