Rough Polishing the 20" f/4.5 Telescope Mirror

This segment shows how to cold press and prepare the surface of the pitch lap. Gordon Waite shows how to set up his fixed-post mirror polishing machine, and demonstrates spin polishing on a 20" telescope mirror.

Category:

Science & Technology

Tags:

• newtonian
• atm
• telescope
• mirror making
• telescope mirror
• polishing
• mirror polishing
• pitch
• pitch lap
• spin polishing
• rough polishing

[datzfast]

i see how this makes a spherical mirror but a parabola?

[GordonWaite]

@datzfast This video just shows rough polishing.  This is really only for removing the pits, and usually produces something pretty close to a sphere. I do the parabolizing stroking by hand with smaller polishers. Thanks! Gordon

[Cyber0Bill]

I'm curious about that hole in the mirror, too... It looks like there is something inside of it. I also noticed in the other videos that it looked like there was something in there... Is it actually IN the mirror, or do you just have something UNDER the mirror?

[hummerume]

@hummerume sorry, i mean "hole" not whole :)

[hummerume]

Hey Gordon,

Excellent posting man, very informative and easy to follow.

One question, why is there a whole in the centre of the mirror?

Regards

[vipond50]

Thanks Gordan

Another excellent presentation!!!!!

Five Star +1

Bill

[TopCat0202]

Like the intro music! Rock on Gordon! ;-)

Tom