... The profile of a focuser with a fixed tube length, i.e. Crayford, is not that of the focuser base, but that of the tube length. If your focuser base has a...
... 5 ... How many times did you go back to a sphere? That could account for 95% of the time it took you to make the mirror. The difference between a sphere...
Ken I never went back to a sphere but three times as I approached the parabula I had to back off toward the sphere as an area had overcorrected. The 1/40th...
Hello everyone: I just listed a full thickness mirror blank for sale on eBay. This is actually a finished mirror but the optical quality isn't very good so...
Ken: The blank is 3" thick. I checked with United Lens once about sawing thick disks. At the time they weren't interested in doing it. Glass Fab might be ...
Thanks Guys! Lots of good info and encouragement. I'm hot to trot. I'll try my hand at a couple of smaller projects to get the feel. I was intrigued with...
... sawing thick ... might be ... James, My machine is dis-assembled now but I can slice it once I get the shop built this summer and the machine back...
Tom, Do a Google for "vacuum bagging". There's a ton of info out there about the process. We seem to forget about the 14.7psi that the atmosphere is exerting...
... machine ... Man, I'd hate to jepordize my Amateur Status... Maybe we could trade some glass for my time and trouble if you still have it at the end of the...
Hi, I'm about start my first mirror and plan to order a Ronchi grating from Edmund Optics. They have various sizes and I'm wondering if there's any reason for...
James: You could also try Rock of Ages, in Barre, Vt. I'm pretty sure I recall a fellow at Stellafane a couple of years ago who had a full thickness sawn in...
It's a very common technique. The main reason it's used is to reduce the amount of resin in the final composite. That directly results in stronger parts. Tony ...
Hi I´m new to this group. I bought a used 10" f/5 mirror two weeks ago. I got it a few days ago and after a quick examine I put it back into it´s protective...
I thought so! BTW have you tried rinsing it with rubbing alcohol? Don’t rub, just wet the mirror down so some of it runs off. Get the unscented variety… If...
Hi Thanks for your reply. I have tried to rub the surface just at the edge whene one of the clamp will be, but no luck. The haze is still there. I´m ...
Not unless you have a) very large eyes <g> or b) can't get your tester light source closer than 1" to where you'd view the return beam I have one and it's a...
I wonder if the coating has reacted with compounds that have been out gassing from some of the packing materials? I had this happen once when a certain brand...
Thanks Mark, While we're at it, would you mind listing a few of your favorite Web or book sources of instruction on how to do Ronchi testing? Thanks again, ...
Thanks for your reply Tony. It could be that the styrofoam gassed the mirror while it was in the package. I have no other explanation. I´ll try using ...
I would try putting the mirror in a tub of luke warm water to which just a drop or two of pure soap has been added. Let the mirror soak for a bit and then...
Thanks Tony! Sounds like a good idea. But if.... if the mirror is coated with silver, wouldn´t the bath damage it? Some people have told me that washing a...
At this point you have no choice, either you experiment with cleaning, recoat, or live with it. From what you’ve stated, this appears to be an oxidized...
I'd think the chances that the coating is silver is very, very low indeed. Almost no one does it that way anymore. Tony ... From: "Lasse Lindh" <3L@...> ...
Lasse Lindh The only real danger with warm soapy water is that if the coating is silver (very unlikely) and your water is clorinated or florinated the clorine...
