2008-2009 Stellafane Mirror Class Session 5 held on 2009-Feb-28
by Jay Drew, Dave & Julie Tabor, & Ken Slater
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Finished Mirrors
We had two mirrors finish up this session, and as you can see from the photos, their makers are justifiably happy and proud.
2008-2009 Stellafane Mirror Class Session 5 held on 2009-Feb-28Finished Mirrors
Fran: 10" f/2 Spherical Dave & Phil flank Fran with his 10" f/2 spherical mirror for a Cassegrain.
Fran: 10" f/2 Spherical
2008-2009 Stellafane Mirror Class Session 5 held on 2009-Feb-28Finished Mirrors
Jeff: 10" f/5 Parabola Jeff shows off his 10" f/5 Parabolic mirror.
Jeff: 10" f/5 Parabola
2008-2009 Stellafane Mirror Class Session 5 held on 2009-Feb-28Finished Mirrors
Dave & Jeff Dave helped Jeff with testing & figuring, and poses with the finished mirror.
Dave & Jeff
At the Fletcher House
With Stellafane still snowed in, we met again at the Fletcher House in Chester.
2008-2009 Stellafane Mirror Class Session 5 held on 2009-Feb-28At the Fletcher House
Setting Up The brown paper is down to protect the carpet, and students are getting set up to work on their mirrors in the main room at the Fletcher House.
Setting Up
2008-2009 Stellafane Mirror Class Session 5 held on 2009-Feb-28At the Fletcher House
Working Along In early afternoon, a row of grinders and polishers work while Phil gets ready to talk in the background.
Working Along
2008-2009 Stellafane Mirror Class Session 5 held on 2009-Feb-28At the Fletcher House
Class Stalwarts Jay & Tom, who a key to making Mirror Class a success, share a light moment in the hall.
Class Stalwarts
Lectures
We had a lecture on Foucault testing for the mirror class, while the refractor group had a lecture on fabrication procedures and issues.
2008-2009 Stellafane Mirror Class Session 5 held on 2009-Feb-28Lectures
Ken Talks Testing Ken gives a talk to explain how the Foucault Test works, and how to read Shadowgrams.
Ken Talks Testing
2008-2009 Stellafane Mirror Class Session 5 held on 2009-Feb-28Lectures
Phil Talks Lenses Phil talks to the Refractor Group about fabricating refractor lenses.
Phil Talks Lenses
2008-2009 Stellafane Mirror Class Session 5 held on 2009-Feb-28Lectures
Fringes Phil explains how fringes on test plates are read.
Fringes
Grinding
It's late in course, so most students that are still grinding are using the finer grits to finish up this stage and then move on to polishing.
2008-2009 Stellafane Mirror Class Session 5 held on 2009-Feb-28Grinding
AlOx Ready to Go 25 micron Aluminum Oxide grit sits ready for us on a tile tool. Add a little water and start grinding!
AlOx Ready to Go
2008-2009 Stellafane Mirror Class Session 5 held on 2009-Feb-28Grinding
Kayla & Rick Rick applies a bevel to Kayla's mirror as she watches.
Kayla & Rick
2008-2009 Stellafane Mirror Class Session 5 held on 2009-Feb-28Grinding
David David fines grinds and 8" mirror.
David
2008-2009 Stellafane Mirror Class Session 5 held on 2009-Feb-28Grinding
Claudio Grinds Claudio concentrates on his grinding.
Claudio Grinds
2008-2009 Stellafane Mirror Class Session 5 held on 2009-Feb-28Grinding
Gary Chats Gary chats with Phil and Randy as he grinds.
Gary Chats
2008-2009 Stellafane Mirror Class Session 5 held on 2009-Feb-28Grinding
Gary & Tom Instructor Tom checks in with Gary as he grinds.
Gary & Tom
Laps
With many students moving on to polishing and figuring, lap making is increasing to support this activity.
2008-2009 Stellafane Mirror Class Session 5 held on 2009-Feb-28Laps
Banished for Channeling Channeling a lap is a messy job, so Dave & Randy work on the deck to keep the mess outside.
Banished for Channeling
2008-2009 Stellafane Mirror Class Session 5 held on 2009-Feb-28Laps
Ray & Dave Ray and Dave chat while the lap warms under the heat lamp.
Ray & Dave
2008-2009 Stellafane Mirror Class Session 5 held on 2009-Feb-28Laps
Two Nice Laps An 8" lap with mirror on top, and a very pretty 6" lap.
Two Nice Laps
2008-2009 Stellafane Mirror Class Session 5 held on 2009-Feb-28Laps
Rick & Ray Waiting for the heat lamp to warm up their laps.
Rick & Ray
2008-2009 Stellafane Mirror Class Session 5 held on 2009-Feb-28Laps
Randy Presses Randy is about to put his mirror on his warmed lap to warm press it.
Randy Presses
2008-2009 Stellafane Mirror Class Session 5 held on 2009-Feb-28Laps
A Nice 10" Lap Samantha's 10-inch lap, freshly coated with Cerium Oxide, ready for pressing.
A Nice 10" Lap
Polishing & Figuring
Plenty of work in this area this session. With Fran & Jeff finishing up, a lot of careful final figuring was done.
2008-2009 Stellafane Mirror Class Session 5 held on 2009-Feb-28Polishing & Figuring
Take Heed! This sign was attached to the deck door - cold blasts of winter air do make the polishers or the laps happy.
Take Heed!
2008-2009 Stellafane Mirror Class Session 5 held on 2009-Feb-28Polishing & Figuring
Fran Figures Fran figures his 10" f/2 Cassegrain primary. He completed it later this day.
Fran Figures
2008-2009 Stellafane Mirror Class Session 5 held on 2009-Feb-28Polishing & Figuring
Carl & Dave Dave makes a point while Carl listens while polishing.
Carl & Dave
2008-2009 Stellafane Mirror Class Session 5 held on 2009-Feb-28Polishing & Figuring
Alex & Samantha They are waiting patiently while they press their laps.
Alex & Samantha
2008-2009 Stellafane Mirror Class Session 5 held on 2009-Feb-28Polishing & Figuring
Exhausted from Pressing Alex & Samantha just couldn't make it while pressing their laps, after all 20 minutes is an eternity when you are waiting. So the used their heads and applied more weight to the press, while refreshing themselves with a nap.
Exhausted from Pressing
2008-2009 Stellafane Mirror Class Session 5 held on 2009-Feb-28Polishing & Figuring
Dave checks up Dave checks Samantha's lap after an initial press. A white 'onion bag' mesh is being used to micro-facet it. He checked Alex's lap right after this.
Dave checks up
Testing
Testing is done in the lower game room at Fletcher House. We had several testers in use, two on 'rails' to help keep things lined up, and Dave's beautiful machined aluminum double-pass tester.
2008-2009 Stellafane Mirror Class Session 5 held on 2009-Feb-28Testing
Two Railed Testers Rails help keep alignment when you need to adjust the mirror to tester distance. In the foreground, Jay's tester use a ladder for this, in the background Ken's tester uses two 10-foot electrical conduits.
Two Railed Testers
2008-2009 Stellafane Mirror Class Session 5 held on 2009-Feb-28Testing
Ken's Tester The test head on this, before the rails where added, was the prototype for the popular 'Stellafane Tester'.
Ken's Tester
2008-2009 Stellafane Mirror Class Session 5 held on 2009-Feb-28Testing
Jeff's Mirror Jeff's mirror sits on the test stand. He built the nice box to carry it around in at lower left.
Jeff's Mirror
2008-2009 Stellafane Mirror Class Session 5 held on 2009-Feb-28Testing
Jeff's Ross Null Tester This is Jeff's Ross Null tester. This test uses a lens to null a parabola in a knife-edge test.
Jeff's Ross Null Tester
2008-2009 Stellafane Mirror Class Session 5 held on 2009-Feb-28Testing
Ray & Claudio Ray & Claudio are new to testing. They practice aligning the tester on Ray's mirror.
Ray & Claudio
2008-2009 Stellafane Mirror Class Session 5 held on 2009-Feb-28Testing
Testing at Radius Ray & Claudio watch Dave (hidden behind the tester). Although the big flat mirror on the tester tells us this can be used as a double-pass tester to test at focal length, here it is being used in single-pass mode testing at Radius of Curvature.
Testing at Radius
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