Mitchell's Telescope Making Website

Check out My Telescope Making Projects!


My ATM Story

     It all started about 5 years ago when I first got into astronomy. I bought a cheap 50mm refractor from a department store. It was good on only the moon. I got curious one day and held up a digital camera to the eyepiece and actually got a picture of the moon! Albeit a very poor one. But I continued to take pictures and they became better, even getting some craters, etc. I soon got a Tasco 4.5" on an EQ mount. Despite Tasco's reputation, this scope was an awesome performer, a real planet killer. I got some really good images through that. This all got me even more curious so I went to the internet to learn more.

     I stumbled upon James Lerch's website about how he had, in just a few days, ground a pair of 8" mirrors with almost no experience. I at first figured this would be only for rocket scientists, but his page made it all seem simple and addressed many of my skepticisms in a down to earth manner. I tore through many ATM pages and a few months later ordered my own 6" mirror kit from Newport Glass.

     It arrived in a few weeks and with the help of some books borrowed from the library I went through rough grinding and started down the grits. I soon joined many yahoo telescope making groups, and the atm e-mail list. I received a lot of help from these people. I owe them much. I continued on till I got to the end of grinding. I was a little confused on just how to go about polishing. Soon I ran into Matt Fuchs and his dad Gary, who brought there own homebuilt telescope to the NJAA Observatory in Voorhees Park, just a few minutes from my house. He helped me with the procedure of making a lap and it came out pretty good. Soon he introduced me down at the ATM Meetings which were held by the generous Gordon Waite. There I got hands on help right in Gordon's own mirror making shop from many experienced people. It was great to have people to talk to one on one and it got me through the ups and downs of polishing and figuring. I finished the mirror to an excellent smooth figure with a good edge, Strehl Ratio of .982 and 1/12.5 P-V Wavefront Error. A Killer Mirror!

     With this mirror completed I designed the scope and put it all together to make a cool looking telescope. See my 6" Homebuilt page. I had first light down at the ATM Meetings and under the city lit skies Saturn was tack-on sharp at over 280X. I am very happy with this scope and I could not have done it without everyone at the ATM Meetings. My thanks go out to them. 

     Well with this scope done I felt empty inside. It wasn't long until I was talking over the idea of making a 10" mirror. See my 10" Homebuilt page. I sped through grinding and polishing and took my time with figuring. It was a little harder since  a 10" mirror has 3X the surface area of my first 6" and a much faster focal ratio, F/4.8 as compared to F/6.5 for the 6". But I finished it to an excellent 1/17.5 P-V Wavefront Error with a Strehl of .990, A smooth surface with a small center defect and a small TDE. So really good, but not perfect. Then as a fun project I did a small 4.5" F/3.8. It was tricky to figure such a fast mirror, and I had my perfect numbers slightly off due to a slightly wrong couder mask size initially. But once the numbers were corrected, the mirror being left as was, still turned out a good 1/9.1 P-V Wavefront. Error, Strehl of .964, with a pretty smooth surface overall and a decent edge. Another good mirror. Now I just have to build scopes for them!

     With these mirrors under my belt I am dreaming bigger. I am working with a friend to build a mirror grinding machine so I can do 16"+ sized mirrors! With Corning no longer pouring pyrex the cost has sky rocketed so I think I will be going with a BVC blank (Black Vitrified Ceramic) or hunting for a used mirror. I also just recieved an 8" Mirror from a friend that is mostly polished out. I am going to complete it and hopefully make an excellent, tracking mounted, planet killer. See my 8" Homemade page.

     And so it continues...

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