Hi All,
Hope this is ih the correct section.
Just joined and need some advice from you folks if that's ok.
I live in WA, 6036 and I’ve been looking for mirror grinding workshops for a while now and haven’t found any.
I have a large paragon electric kiln which I have modified and built myself a grinding machine for the blanks that I produce. The problem is the blanks aren’t grinding as well as expected so I was very interested in a mirror grinding workshop for some hands on experience.
Was prepared to travel to the US for a workshop, as long as it was more than a couple of days to gain some experience, but thought I would exhaust my searches here first. Then had this brilliant idea to ask an experienced person for help first. Tried the West Australian astronomy club but it appears there’s not enough call for it. It’s not so much a person having ground one although that's a hell of an achievement it’s more of a workshop situation that I’m looking for at the moment.
What do you think, have you heard or been aware of any.
sorry cant help with the mirror grinding workshops. Your using grinding machine, all my work is by hand so not able to give advice with machine work either.
Curious about the blanks your making. What is the substrate material? and what sizes are available? Annealed?
The substrate is Borosilicate glass and they range from 6",8",10",12" and 14" in 2" increments at present, hoping to go to 25" sometime. Also smaller ones are 1" thick and larger are 1.5" thick, yes they are all annealed.
Have been trying to create a devit free blank but finding it very difficult at the moment as it could be the glass I'm using (particular manufacturer), also finding it difficult to parallel the faces as I'm getting a slight convex shape at present. Still trying various mods to the grinding machine to overcome this.
Question if I may Stephen, the glass blanks you use do they have any devit in them. The reason I ask is when grinding etc does the devit in the glass affect the surface finish and also does it still polish?
Have you ground and polished many blanks and have you mounted them into any telescopes yet.
The devit is surface and also internal although surface is not so much a problem, apparently the glass rods can pick up contamination from the metal when the liquid glass is falling through the metal tubes to produce the rods. It is actually in the surface of the glass as I understand it. I've tried various methods to reduce the possibility of the devit by cleaning etc to no avail, can't grind it off as this isn't practical and anyway the grounding itself would probably cause devit also. Anyway still working on the solution.
That's interesting about the aquarium glass, how thick does it come in?
That's interesting about the aquarium glass, how thick does it come in?
Best Regards,
Terry
I had 4 viewing panels (1200 kgs),some were 1 3/8" others 1 1/2". Almost all gone now.
I sent at least one blank to W.A. I think a 16". Wonder how thats going.
Best Regards
Stephen.
Some of original stock. Nearly all gone now, to US, AU, and local. Had blanks 12" to 33".
to US, AU, and local. Had blanks 12" to 33".
