Saint Petersburg Astronomy Club - Mirror Lab


We are looking for a new home
As soon as we have the new location set we will post the location and hours here.

Our Founder

Paul McNabb founded the mirror lab in 1997 in order to create the best amateur telecopes possible. Inch for inch our mirrors surpass store bought or commercial grade scopes.

04/12/2012 more


  • Ralph Craig - Lab Instructor
  • Allen Maroney - Lab Instructor
  • Ron Jones - The Figurer
  • Mike Davis - Casts Mirrors
  • Dimitri - Support


  • James Lerch - Robo Foucault
  • Matt Terry
  • Charlie Mullen
  • Bruce Kazcmarik
  • Keevy McAlavy

In Memorium

  • Irv Nadelhaft
  • Lenny Remetta

04/12/2012 more


Where the 19th Century Art of Mirror Making Meets the 21st Century

The Saint Petersburg Mirror Lab is a small band of dedicated mirror grinders and telescope makers living in the Tampa Bay area of Florida. We offer a mirror making class for interested persons. We strive to create the best mirrors our home brew technology can muster. This includes robotic foucault testing and laser interferometry.

  Maiarotos Win at Stellafane
Steve Maiaroto and his grandson, Steve, entered their 8inch f/7 telescope in the 2019 Stellafane
optical and mechanical competitions. They won second place for optics in the 12.5" and under
category and honorable mention for mechanical. Steve originally ground his mirror at The Franklin
Institute in Philadelphia years ago and then repolished and figured his mirror at the SPAC optical
lab (see the 3-17-2019 photos below of how the mirror looked before and after). Congratulations

  Maiarotos Win at Stellafane
Here is the competation info that was attached to the telescope and the Stellafane emblem to show it
was in competation.

  The Optical Lab is Moving
The Science Center has been sold and we had to move out of our 20 year home in the building in the
back field. We are working on a new home so check in here for updates. Until then the lab gang
will be using some the telescopes that we have made and building others that only have finished
optics. We'll post all of the updates here.

  Telescope Lab Visits NASA Portable Observatory and 30 ft Dish
The Telescope Lab gang (l to r: Ralph, Paul, Brad, Mile and Allen) visited an Apollo era NASA
portable observatory designed to track launches if the primary tracking system failed. The
Observatory is the dome on the left of the photo. There was also a 30 foot working satellite dish
that was pretty cool to see swing around.

  Bill urethaning the mount for his 10 inch Dob
Bill put some effort into waterproofing the mount for his new 10 inch dob. There is a little
assembly needed on the tube yet. Soon there will be star light at the end of the tunnel.

  Bill's mount ready for the optical tube
This is a knock-down Dobsonian base where the sides come off and the front folds down to fit in a
small car. Bill and Ralph designed this and they did a great job.

  Dimitri finished his 12.5 inch mirror
Dimitri made an amazing 1/9th wave mirror with a beautiful edge and a stunning polish. This will
make an exceptional telescope. Congratulations Dimitri!

  The Mirror Lab Whiteboard
This is a thing of beauty. Every few months we wipe it clean and start over. It's fun to see the
history and how many mirrors were completed.

  Rough mirror made smooth
Steve Maiaroto brought in an 8 inch piece of glass that he polished and figured years ago. We put it
on the Foucault machine to measured the surface and it came out to sixth wave, which is better than
our minimum requirement of quarter wave. Unfortunately, we detected a polishing issue that needed
addressing. Periodic marks were rubbed into the glass as seen in image A, which can contribute to
scattering and distortion. The most likely causes for this issue are aggressive rubbing, lack of
randomness or a hard pitch lap. We poured a new pitch lap and decide on the best stroke to work out
the pattern without affecting the shape. It took about 2.5 hours of rubbing to get the results you
see in image B.

  Grinders in the Shade
Brad, Richard and Mike(l to r) grinding and Paul in the background prepping a tube for black paint.

Goto Page
 0  1  2  3  4  5  6  7  8  9  10  11  12  13  14  15  16