3683 mm give or take 10mm. I forgot to get the exact ROC during Foucault testing. I would have gone back except the astig and surface roughness were the...
Tony at Owl Optics. Apparently the Hubble sandwich mirrors are harder than normal to refigure for various reasons attributed to the sandwich structure. So...
The label on the box says 71.39", which would correspond to 3627mm, so I would say not. One can discount their "S-Ratio" but I think their F.L. is likely...
That would seem worth it, however, how good is the substrate on these HO mirrors I wonder? I have no idea, but just curious whether it really is worth doing...
I have a 14" that I'm happy with. My 16 that was refigured tested excellent, but I haven't installed it yet. I have high expectations though... Tim in...
I will post an account of what I find, and what happens to this mirror regardless of how it turns out to do my part to avoid sampling bias (perhaps bad mirrors...
Hi I'm thinking about getting a 25+ inch dob but one topic that I can't find much info on is the process of installing the heavy mirror into the mirror box. ...
Hi Denis, You didn't mention the thickness you plan to have, but if it is 2", then a 25" mirror will be heavy (F/5 Pyrex is 73 lbs.). I have a 20" F/5 mirror,...
Hi there When I clean my 25" mirror , yes it is a 2 person job , there is room but mirror should be on a small angle . And I have one rule , it doesn't matter...
I have the 25 Obsession. The last time its mirror was lowered into the box, it was fairly easy for two of us, clearance was no problem. You can make a net of...
I don't lower my mirrors into any mirror box. My mirrors are installed in the mirror cell while it is outside of the mirror box. Once installed in the cell,...
I totaly agree, My homemade telescopes have a desgn where the bottom of the mirror box with the mirror can be unbolted easily and the rest of the mirror box...
I use an improvised "cake stand" to load the mirror. In the plywood back of the mirror box I drill three large equidistant holes (this step isn't necessary...
Hello everybody, The 1100 mm telescope project we commenced in 2007 is taking a second start after nearly 4 years of interruption. See the web page for the...
Robert, I have been waiting to see the result of this for a while... although I am sure not as much as you! Thanks for posting this milestone, and glad you...
Mike, Isn't that almost maximum diameter can be made if you take that the width of Supremax glass block is 1200 mm? Zoran ________________________________ ...
Zoran, ... Yes, you're correct. If you try to cut out a larger blank, the glass might not be thick enough near the edge to yield a uniformly thick blank. I...
Your mirror may be a little like mine, in that in addition to simple dust and pollen you build up a haze of organic material over time. This technique seems to...
Hello Don !! Ive watched this video, and This guy knows what he is doing. I do not wish to take my mirror out of the scope, but I can do the same thing...
Most fans have non-rustable bearings, so getting them wet wouldn't be a big issue so long as they were completely dry before applying any electricity to them. ...
You are right Don, Rust is a protential threat. I use stainless steel for all fastening hardware in my scopes and aluminum for any metal components. For...
Call Howie direct. His number is at collimator.com. Sent from my Verizon Wireless 4GLTE Phone ... From: Jud <manisteej@...> To: bigdob@yahoogroups.com ...
