It's been a while since I reported on my first attempt at mirror making.
I started a year ago, working on and off, with a 12.5" pyrex blank.
It took me 20 hours to polish out using CeO on a slightly-less-than-full-sized pitch lap.
I've been doing some figuring since then.
I include some images that I took with a camera in the workshop -- they give an idea of where I stand after my latest figuring session.
The mirror has a few minor scratches -- nothing that makes me want to go back to fine grinding and 20 more hours of polishing.
Here's the Ronchigram (outside RoC). (It's a f/6.3 mirror: D=318mm / FL=2002mm)
Clears,
Joe
I started a year ago, working on and off, with a 12.5" pyrex blank.
It took me 20 hours to polish out using CeO on a slightly-less-than-full-sized pitch lap.
I've been doing some figuring since then.
I include some images that I took with a camera in the workshop -- they give an idea of where I stand after my latest figuring session.
The mirror has a few minor scratches -- nothing that makes me want to go back to fine grinding and 20 more hours of polishing.
Here's the Ronchigram (outside RoC). (It's a f/6.3 mirror: D=318mm / FL=2002mm)
Clears,
Joe
Attached Image:
In lumine tuo videbimus lumen.
8O Home-made 10” Dob / Home-made 4” refractor
EPs: Konig 32mm (1.25") / Zhumell WF 30mm (2") / Nagler 13mm T1 / Orion Sirius Plossls 25 & 10mm / Zhumell Plossl 9 mm / Meade MA 9mm