Though I have other instruments, I still use my 1970's ATM scope. It's a 6" f7 built by me as a teenager as a member of the Amateur Telescope Makers Club of Queensland(ATMQ).
I began by ordering a mirror grinding kit through the Brisbane shop of Astro-Optics. I had forgotten if I started in 1978 or 1979. Roy Axelson, AAQ Secretary, recently while sorting and clearing out archived material found my name in an old high school astronomy club newsletter and sent it to me. It pins my start date around or just before September 1978.
I completed the grind on my own then early 1979, I joined the ATMQ. It's president and the person who owned all the workshop facilities was Cliff Duncan. Cliff was a master optician and became an incredible mentor to me. We discovered that I had turned down the edge of the mirror. I think Cliff saw an opportunity to teach a young impatient teenager some patience and application, arguably the most valuable thing I learned from the whole process. He said, " Joe, I recon you can polish that out. Waddya think?" Respecting his opinion, I agreed and in a polish on polish off type situation began a very very long process polishing out a badly turned down edge. I worked 35 years as a scientific instrument engineer repairing mass spectrometers and along the way, found myself teaching the same patience lesson to my many young impatient trainees. In parallel to the optical work, the club had a very active engineering operation. Cliff had a small foundry in his backyard and we cast any parts that could be made this way. Ingots of aluminium and zinc were purchased at Sims Metal in South Brisbane.
Pier legs, bearings, angle bracket between bearings, saddle and tube yokes rotation rings, mirror cell and focuser were all cast from aluminium, brass or steel bar or tube was machined to complete the fabrications where necessary. Counterweights were cast from zinc.
In the process, Cliff taught me and many others how to use handtools safely and accurately and also how to use machine tools like lathes, off hand grinders, and drill presses. It was a fantastic experience and one from which I took away so much more than a beautiful telescope.
When I had the mirror very close, Cliff did the final figuring while I was away with family on a Christmas holiday. After I had spent so much time, I had mixed feelings of disappointment and gratitude that this occurred in my absence.
Cliff's final figuring was superb and even in a recent comparison 4 years ago between my reflector and a Takahashi TOA150, we had to work very hard to separate the views through the two instruments.
The scope is set up as a visual instrument with a small 3.5% central obstruction from the diagonal. The ATMQ mounting is one that Cliff based on the Springfield Porter mounting with large disc bearings. The closest modern equivalent might be the Disk Mount.
http://www.discmounts.com/
The design rule Cliff used was that the bearing diameter had to be the same as the mirror diameter. This makes for a very smooth motion. After a recent clean and re-grease, it was a bit too slippery at first but this is gradually sorting itself out. Usually, it is a very smooth and easy one axis equatorial push motion.
The steampunk wheel at the base of the counterweight shaft turns a 5/8" thread inside the steel tube. A fork protrudes through a milled slot in the steel tube to push the zinc counterweight up or down. The most fantastic feature of this scope are rotation rings that allow the eyepiece orientation to be easily rotated into a position for comfortable viewing regardless of where the scope is pointing. Uncomfortable eyepiece position is a huge disadvantage of most equatorially mounted newts. The rings recently had become quite sticky. The old dry lube had become quite sticky and impregnated with grit. A thorough clean with kero and new lube application to the rings and yokes, this time with candle wax has fixed the problem.
The original finder had both an objective and eyepiece from a pair of mechanically stuffed binoculars that I purchased from a binocular repairer for $5. They were mounted into PVC plumbing fittings. When these photos were taken a few months ago, I was testing a 63mm binocular objective. The objective was just taped in place at the time of the photo but I have since fixed it permanently with a high strength, high temperature, metal epoxy adhesive putty. I have also replaced the eyepiece with a very nice plossl making a beautiful 9x63 finder, highly recommended for older failing eyesight.
The scope saw first light in August 1980, 2 years after I commenced the build. Although I have a Vixen VC200L and an 18" f5.5 dob, I still get a lot of pleasure using this scope very regularly, now in it's 42nd year of operation.
The focuser is made from a cast aluminium base holding 3 smooth, sliding brass tubes. The focuser only takes 1.25" eyepieces but given the 3.5% diagonal obstruction, 2" eyepieces would be wasted. I currently use a Unitron 40mm Kellner, Denkmeier 21mm and 14mm, Pentax XL10 and XL5 and a Nagler 7mm in the scope. On a night of exceptional seeing at Mt Tamborine Observatory in May 1984, and I mean truly exceptional, Arthur Page loaned me his 6mm Clavé eyepiece and 3x barlow. I had the scope at 500X showing crisp, clear, clean, images of Jupiter, Mars and Saturn. I have only struck similarly stable conditions that good on 3 nights out of 44 years of observing, two nights in May 1984 at Mt Tamborine and October 13, 2020 near Yass.
In 2017, and because the optics are so good, I decided to spend $420 at Palmway Optical to have the mirror and diagonal re-aluminised and over-coated, a decision I don't regret. I have also made a jig/adaptor so that I can remove the saddle plate and yokes and attach them to a dovetail allowing the OTA to be used with my Takahashi EM200 GOTO mount.
Joe Cali
) as I'd like the 2" capability that the Ranger lacks. 
