First Pitch Laps Of The New Season

For our first class, Francis O'Reilly is the new leader. Here are some pictures from the Bunkhouse with pitch laps in action.

2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 First Pitch Laps Of The New Season Stephen's new lap in progress. The hot pitch was just poured into a well used pitch lap mold and the plaster tool was plunked on top. Hidden underneath is the mirror, face up. Now we wait for the pitch to cool before separating them.	2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 First Pitch Laps Of The New Season Keith is parabolizing his 6" f/7 mirror.	2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 First Pitch Laps Of The New Season Reade is using a razor blade to cut new channels, allowing the pitch to conform to the mirror and the cerium to flow.
2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 First Pitch Laps Of The New Season We carefully use heat lamps to warm up pitch when a good pressing is needed. Too much time on the tanning bed can melt the pitch right off though!		2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 First Pitch Laps Of The New Season Stephen's new lap is hot off the mold and ready to polish.

An Interesting Cure For Turned Down Edge

Dave Kelly, a professional Optician and a life long ATM, is the guru of the figuring stage of our Telescope Making Class. Dave uses a precisely measured star lap to "cure" TDE.

2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 An Interesting Cure For Turned Down Edge Using the plastic material from a flexible 3-ring binder, Dave cuts a star lap.	2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 An Interesting Cure For Turned Down Edge We cut a 4" square for a 6" mirror, and then use the mirror's edge to cut out radii from corner to corner, making a diamond shape.	2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 An Interesting Cure For Turned Down Edge The Star is pressed into the lap for a few minutes, leaving a central area of pitch that doesn't contact the glass.
2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 An Interesting Cure For Turned Down Edge The star is well pressed into the pitch now.	2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 An Interesting Cure For Turned Down Edge Dave demonstrates the stroke to use: it is a long sweeping center-over-center stroke that wears down the area just inside the Turned Down Edge.	2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 An Interesting Cure For Turned Down Edge Ready to sweep that edge. The depressed area of pitch is easily seen through the back of the mirror. Drat that Turned Down Edge!

Polishing

We try to get a picture of everyone who is polishing, but this year we missed a few mirror makers. Here are some of our folks hard at work.

2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 Polishing Reade is working on his second mirror, a gift to his grandchildren.	2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 Polishing Andy wins the prize for longest distance travelled, coming from Pennsylvania for class.	2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 Polishing STM Cecelia is hard at work on her 10" mirror, making great progress.
2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 Polishing Caleb is doing #220 grit on his 6" f/7 mirror.	2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 Polishing Caleb is grinding with a pregenerated set from Newport Glass. These are very high quality mirror/tool combos with the initial sagitta already ground in. No hogging required.	2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 Polishing Stephen is a professional magician and pulled this pitch lap out of a top hat...well maybe not but in a parallel universe it could happen...
2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 Polishing Stephen came to class with his mirror already well ground and polished from independent work at home. We're looking forward to seeing this one on the Foucault Tester soon.		2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 Polishing George is new to class this year. His 8" f/6 is hogged out and #220 is in progress.

Testing and Figuring

Some of our figuring crew. Unfortunately we didn't finish any mirrors today.

2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 Testing and Figuring Dave Kelly sets up his amazing test rig. It is all aluminum and very precise.	2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 Testing and Figuring Keith is adjusting his mirror in the test stand of our mirror tunnel. The tunnel cuts out drafts and stray light, and a rail system makes it easy to switch between different mirrors during the figuring process.	2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 Testing and Figuring Dave stands on a precision lift mechanism to reach the eyepiece height of the test tunnel.
2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 Testing and Figuring Dave uses a laser to decide if the mirror has been "polished out," in other words, to determine if the polish is complete and ready for figuring.	2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 Testing and Figuring STM Phil Rounesville is a dedicated mirror class instructor and lends his vast knowlege to our students monthly. Here he is helping with testing.

Machine Grinding

Past President Jeff Lowe is fine grinding his 17" f/5 mirror on our Strasbaugh Grinding Machine.

2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 Machine Grinding Jeff applying 15 micron Aluminum oxide while fine grinding his big mirror. The job is done inside a plastic booth to keep other mirror maker's grits from contaminating everything.	2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 Machine Grinding Jeff's mirror is chocked into the machine's turntable after careful centering.	2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 Machine Grinding Jeff's subdiameter dental stone and tile tool is ready to go. It has a flange held on top with blocking pitch. This socket will hold the overarm of the grinding machine.
2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 Machine Grinding Jeff applying 15 micron Aluminum oxide while fine grinding his big mirror. The job is done inside a plastic booth to keep other mirror maker's grits from contaminating everything.		2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 Machine Grinding Jeff poured a new tool this morning using a pleasingly blue dental stone. He'll use this for further grinding and polishing once it cures in a couple of weeks.

Telescope Making in the Pavilion

Class Leader Francis O'Reilly has re-dubbed the Mirror Class as the "Telescope Making Class." He is planning to help each student build a complete telescope, and to that end has recruited club member Glenn Jackson to begin building the Stellafane Mount designed by VP Ken Slater. Complete plans are available on our website.

2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 Telescope Making in the Pavilion Glenn adjusts his router while cutting circles for the mount he is building.	2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 Telescope Making in the Pavilion Glenn at work in the Flanders Pavilion.	2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 Telescope Making in the Pavilion The cradle for Glenn's mount is nearly finished, holding the future telescope tube firmly.
	2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 Telescope Making in the Pavilion Glenn's paver is underfoot as he works away.

Fall on Breezy Hill

Columbus Day Weekend is Vermont's busiest for Leaf Peepers. We had quite a show of blazing fall folliage at Stellafane too.

2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 Fall on Breezy Hill Just a few pictures for the leaf peepers.

2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 Fall on Breezy Hill The area behind the Bunkhouse.

2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 Fall on Breezy Hill The road to The Woods.

Around the Site

Some pictures of other activites going on today.

2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 Around the Site Dave Prowten took some time out from building the Spectrohelioscope and fixed several jammed/mishung doors in the Bunkhouse.	2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 Around the Site Tom Spirok and Ken Slater have been working hard to upgrade the systems in the Bunkhouse. Here is their NASA-ready manifold for the plumbing.	2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 Around the Site Mirror Class Leader Francis O'Reilly has been working on the club's 27" mirror. This full thickness beast is well known to Convention goers, who have been helping grind it for a decade or more. Francis hopes to take it to the next level this year. Here he is using a simple depth gauge to measure the sagitta. A 36" length of aluminum square tubing with a dial indicator in the center does the job neatly. We use these extensively (in smaller sizes) in the Mirror Class.
	2015-16 Stellafane Mirror Class Session 01 held on 2015-Oct-10 Around the Site For more precise measurements of the radius of curvature on the 27" mirror, Francis uses his spherometer. Here it sits on an optical flat to "zero" it out.