Posts Made By: Ron Martinez

Anyone know where I can find a replacement for Meade's secondary mirror and holder for their 16" dob Starfinder? I had put epoxy over the aluminum plate that the flat attaches to, and that wound up bending the aluminum piece when it hardened, which is distoring my images tremendously. I tried removing the epoxy (successful) and reattaching the mirror with silcone rubber, but this didn't fix the problem. I can't bend the aluminum back to perfect flatness, so I would like to either get a duplicate mirror and holder, or get something better to replace the 4" mirror/holder. Any suggestions? (since I did the epoxying, bright objects like Mars and Venus show as multiple ghosts, and I can't resolve stars to pin points at high mag, which is quite frustrating! I read in a post that someone thought the Meade 4" secondary was too big for this scope. Opinions appreciated. Thanks in advance.

I've been hoping that some day "soon", someone will come up with a process to make high quality thin composite mirrors at a price us amatuers can afford. One sight I've been watching for a while is Composite Mirror Applications (Peter Chen's company) at:
http://www.compositemirrors.com/
Go to their Publications link, click on Ultra Light Composite Mirrors and flip through the acrobat file. Also click on Apodized Apeture Exo-Planet Detection and look through that acrobat file and be amazed! Supposedly from articles I've read, CMA wants to eventually make composite mirrors for amatuers at a reasonable price.
I've read that there are hundreds of composite mirror companies in Arizona, but CMA is the only one that I've been able to find online. Has anyone investigated this line of mirrors/costs, etc? Or has anyone tried to make a composite mirror? I've often thought it would be interesting to take a 24" light reflector that's been machined to a parabola, and have it silvered to be highly reflective, and see if it would produce a decent image. I suppose someone's tried it before and it didn't work. Anyway, any thoughts on this?

Ron

According to Meade's website, they do:
"All Starfinder models, both Equatorial and Dobsonian, include a superb, hand-figured parabolic primary mirror manufactured of low-expansion, fine-annealed Pyrex® glass at the Meade Irvine, Calif., factory. Every mirror meets the theoretical limit of resolution for its aperture, and is matched with an elliptical flat secondary mirror of appropriate minor axis. Mirrors included with Equatorial and Dobsonian models are identical in optical quality, performance, and specifications."