Thanks Mark, Good questions I need answers to. How can I test the mirror to see what typr of mirror it is. If it is spherical (like most Cassegrains) then...
Thanks Mark It's an f7.8, so it will need parabolizing, I presume. I forgot to mention that I'm doing very short (1cm) strokes trying to get rid of the TDE....
Better to be safe than sorry. As the abrasives get finer, you will use less for each wet and the wets will last longer (as they should). And you can get by...
Mirror is indeed smoothening properly, everytime I switch to new abrasive, after just 1 wet, I feel change in its surface, visually and in touch also, at 320,...
Classical cassegrains do NOT have spherical primaries...they are always parabolic and use hyperbolic secondaries. But a classic cassegrain is one of a family...
Working the crest of the TDE with pressure a bit more difficult to get right than the similar alternative of applying pressure on the over hanging edge of the...
Or a newborn baby's bottom! That's good. As the abrasives get finer, the mirror glass will get more like wax paper in it's translucency. It will never get...
Working the crest of the TDE with pressure is a bit more difficult to get right than the similar alternative of applying pressure on the over hanging edge of...
The video shows working MOT so the pressure is on the side of the mirror inside the edge of the lap. Working TOT the pressure would be on the overhanging side...
I ask because if the TDE is a broad zone, more of a roll, then you may be able to parabolize anyway, provided the correction at the edge is not more than the...
Thanks so much for the advice guys. I did one 20min. session of the method shown in the video and can already see the result. Wow, I'm excited now!! (it's...
I noticed that the lap in the video is not beveled around the edge. So the top surface of the lap is the same size as the mirror. I wonder if that helps the...
Go to: http://www.loptics. com/ATM/ The are are links on figuring (parabolizing strokes) and oblate spheroids as well as a lot of good information. Note that...
Thanks Mark, I'll have a squiz... Christo ... From: Mark Whitaker To: atm_free@yahoogroups.com Sent: Monday, November 02, 2009 10:44 PM Subject: Re: [atm_free]...
Hey MArk, Thanks for the advice. Since you are the man with the knowledge can you tell me why the SCT has a corrector plate? From what you've told me there is...
Hey Guys, I was wondering, I am looking at the secondary mirror for my cassegrain that I'm making. For an 8" secondary mirror (hyperbolic) the size should be...
At f:8 (rounded) you shouldn't need to alter the lap to with stars or trimming spedial shapes into the channel pattern. I suggest that you not press stars into...
Hey! There is another youtube video there. http://www.youtube.com/profile?user=curiosis#p/u/0/iqdaM-yWrtQ You would have to know when to use this one....
It is a matter of design. Classical cassegrains do not need corrector plates while in the case of the SCT design, it is essential. Most commercial SCT's are...
Mark I enjoy reading your posts. You remind me of my Australian High School Physics Teacher Father John Burns. There is humour at the end of your post too. Ali...
He does sound like my high school physics teaher as well, Brother Leahey. But like my former teacher his advice is for you to decern and accept or prove...
Mark, I admire your spirit. You can indeed actually make a Classical cassegrain, SCT or Ritchey-Chretien. Other amateurs have done it. It's a great challenge...
The warning is basically the same that Texereau puts forth. When you read it, it almost seems to dissuade the amateur from building the cassegrain. It is a...
Good points. Is Texereau still alive. He would be 90. He was a world class professional telescope maker. IMHO, his book "How to Make a Telescope" is required...
Hey guys, I am taking the advice of Mark and just got a copy of How to Build a Telescope by jean Texereau. I've also ordered Telescope Optics. Now I would like...
Mark, I am taking the advice of Mark and just got a copy of How to Build a ... I would add Star Testing Astronomical Telescopes by Harold Suiter. It's more...
Mark, if you are at all interested in the beginning of Amateur Telescope Making, I would recommend the original "Amateur Telescope Making", "Amateur Telescope...
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