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The Giant Binocular
- Thread starter savarin
- Start date
- Joined
- Aug 22, 2012
- Messages
- 4,254
spherometer to start for a rough idea then onto ronchi and foucault.
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message 44 for a pic
granite dresser tops for a surface plate or for lapping?
Savarin it happens that i have a good interest for optomechanical measuring devices.May be we have to open a new thread for discussing these.I am a little confused with the new software and i don't know how to open.So you are burdened with this difficult task taking the opportunity to present...
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- Joined
- May 16, 2016
- Messages
- 1,703
I think you only have to live long enough, and you'll get there. Keep at it old mate.
- Joined
- Aug 22, 2012
- Messages
- 4,254
I have two spherometers, a large imperial one and a small metric one.
but do you think I can find them, I have looked everywhere (except where they are) and cant find them, my wife has said she has seen them but cant remember where so I had to make another in the hope that would make them magically appear. No such luck.
the dial is set at zerp on a dead flat surface. the three pointy feet sit on the mirror, the reading is the depth of the curve thats ground in.
But, the distance between each foot is recorded, the distance between each foot and the centre is recorded, then the application of some maths gets a pretty accurate measurement for the depth of curve (sagitta) once that is known some more math will give the focal length of the mirror.
If you take readings from different parts of the surface hopefull they all read the same thus showing a ---- I hesitate to use the word perfect but pretty close surface.
but do you think I can find them, I have looked everywhere (except where they are) and cant find them, my wife has said she has seen them but cant remember where so I had to make another in the hope that would make them magically appear. No such luck.
the dial is set at zerp on a dead flat surface. the three pointy feet sit on the mirror, the reading is the depth of the curve thats ground in.
But, the distance between each foot is recorded, the distance between each foot and the centre is recorded, then the application of some maths gets a pretty accurate measurement for the depth of curve (sagitta) once that is known some more math will give the focal length of the mirror.
If you take readings from different parts of the surface hopefull they all read the same thus showing a ---- I hesitate to use the word perfect but pretty close surface.