Stargazing Build Concave Mirrors Up to 1.5M Dia: Design a Grinding/Polishing Machine

[les trickett]

We Are Trying To Design A Grinding/polishing Machine To Manufacture Concave Mirrors Upto 1.5 M Dia
Does Anybody Have Any Plans For Construction

 

[Chronos]

Try here:

http://www.oblivion.net/~astro/mirror/mom/construction.html

 

[sas3]

If you "Google" Grinding/polishing Machine you will find a lot of good links.

I have a Odyssey 1 Dobsonian and have been thinking of building an equatorial mount for it.
I am thinking of using an old front wheel housing from a junked car for base of the mount has anyone tried this or know someone who has?

I figured that the wheel housing would be over-kill but more is better than less when it comes to stability, as for the mount to the telescope itself I have some 1/2 inch steel plate that I can cut up and make a fork mount out of it. I know it will be heavy but it is going to be in a building and will not be moved.

Any suggestions for a clock drive and setting circles set up would be appreciated as well as any other construction tips.

Thanks

 

[Chronos]

The principle for grinding a spherical surface is quite simple. Uniform pressure, linear motion of one of the surfaces, and rotation of the other surface. A small amount of randomness in the stroke, rotation speed or both is even better. Pre-sphericized glass blanks are commercially available pretty cheap. It's worth a look, you might be surprised how large and inexpensive these can be. It's not hugely expensive to make your own rig, but not cost effective unless you can sell a couple rough ground mirrors. Making clock drives is surprisingly difficult. You need gears with weird teeth numbers to make it work on house current [60 Hz], or some fairly pricy frequency converters. Albeit frequency converters might be a lot cheaper now than the last time I priced them.