Astronomy Club Workshops

Fall/Winter 2003 mirror grinding class

The mirror grinding class will meet on Thursdays from 8pm - 10pm in the club room in the basement of the observatory.

The time has come to start preparing to grind your mirror. For a good primer on the process, read the article at:
http://bobmay.astronomy.net/mirrormaking/makemirror.htm
For those of you doing a 6" or 8", we will use the glass tool method.
For Ratnam, who is doing a 10", he will be using the plaster/tile tool method.

You will need most of the materials from the list I sent out previously. Make sure you have your grinding stone, as it is the first thing we will use. Also, be prepared to carry your glass and supplies home with you, since I am encouraging you to work on it out of class, too.

Bring a marker and put your name/initials on all the objects that belong to you.

During the first class, we will put a bevel on the mirror with the grinding stone, we will choose which side will become the mirror, we will start grinding the other side (the back) flat, and we will prepare the front face of the blank to become a concave optical surface.

Pictures from grinding and testing sessions

• Various pitch laps, tools, and Couder masks
• Pictures from the first mirror grinding class
• Pictures from the second mirror grinding class
• Pictures from a focault test of a finely polished 6" mirror
• Pictures from the third mirror grinding class
• Pictures from the fifth mirror grinding class
• Several Focault shadowgrams of Ben's commercially produced mirror and two shadowgrams of Mike's hand-polished 6" mirror
• Pictures of an 8" plate glass tool which cracked due to thermal shock as a result of being worked on in a cold garage while the pitch was being trimmed and channels were being cut
• UIAS mirror grinding class pouring and trimming their pitch laps

Costs, required materials and equipment, etc

• Final Costs
• Required supplies, tools, containers, etc

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