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How I Built My Telescope

Asad Mehmood with his 6" Newtonian Reflector, built by him.

 

"Asad is a youngster hailing from a small town Okara in Pakistan. He has recently completed his 6″ Newtonian Reflector after a lot of hard work. He has written his story of telescope making and here I present it before you"

Without a deep interest in any field of work, one is unable to achieve the height of glory in that field. Patience, laborious work and hope for the best, leads us to reach our goal always.

Likewise, the art of ATM (Amateur Telescope Making) has be

How I Built My Telescope

en the most interesting fun and ambition for me for the last few years since my school times. By then, I used to make small refracting telescopes trying always to somehow increase the resolution of the image. About two years before, Lahore Astronomical Team arranged their “3rd Astro Fest” at my school in Okara. I still remember that great event involving two great persons, Sir Ali Khan and Sir Umair Asim who later provided me a great service due to which I could be able to finally build a successful

6″ Newtonian Reflector. The Principal of my school introduced me to them and since then, my eager for building a larger telescope increased.

 

Asad mehmood's telescope

Interior of the tube.

I kept contact with Sir Ali Khan, a true helper and an optimist. He kept on encouraging me to grind a mirror for reflecting telescope. Later, I went to Lahore, searched the market along with Sir Ali Khan and bought grits (the grinding material) and 8″ mirror blanks and then returned back with a charming dream in my mind. Then I started the mirror grinding process with the constant help of Sir Ali Khan and of some experts from Telescope Making group at Yahoo. The names of some of them are Mark Whitaker, Jerry, Vladimir, Berthold Hamburger (who sent me the Ronchi grating for the Ronchi Mirror Tester) etc. These are some persons to whom I am very grateful. I learned a number of techniques, effects of different strokes, the effective way to grind/polish, etc as well as earned a great and nice experience. By some way, after regrinding, re polishing, regrinding, re polishing up to the correct figure of the sphere that my 8″ mirror achieved, I was too happy to up looking my dreams turn into realities.

Ready to explore the heavens.

As it is said, “We can’t always get the things we desire”, something similar happened to me. My mirror somehow fell down and shattered in countless pieces. That was a truly grievous incident for me but I didn’t allow myself to be broken hearted and thought to try again with some other mirror size. By that time I had a lot of information and experience. I knew well how to grind effectively, how to generate and spread out a fine curve, how to control the concentration of pitch based on temperature to make a pitch lap for polishing, how to polish in a right manner without distorting the actual figure( sphere) of the mirror. Having all that in my mind, after about 8 or 9 months I restarted my work but that time, there was a 6″ mirror instead of 8″. After deciding its desired focal ratio, I started the grinding process with the name of Allah, promoted to fine grinding and then to the toughest and the most laborious task, the polishing. Polishing process opposed my way to exceed further but I kept my work hard until I achieved the pure spherical figure of the mirror. Two types of basic mirror shape testers are used in ATM i.e. Foucault Knife Edge Tester and Ronchi grating tester. I had needed to build these testers too and it added increments in delaying my further work. A lot of Cerium Oxide (polishing agent), pitch and plaster of Paris disks were consumed but at last I got the desired shape of mirror. This was a great success for me for the first time in my life. Everyone appreciated and congratulated me.

 

Cool and Refreshing shot.

The next and last step of ATM is coating the mirror with Silver or Aluminum. Since Silver is more reactive with aerial Oxygen than Aluminum, therefore I started worrying where to find a coating chamber for Aluminum coating on my mirror. More than 4 months spent but no one of the group mates from Karachi Amateur Astronomers Society, Lahore Astronomical Society, and Pakistan Amateur Astronomers webpage could find the coater who dealt in mirror coatings. Finally I found a person, Mr. Zafar Iqbal in Islamabad who is an engineer by profession and has links with few of the expert coaters working in Govt. Military/Defense area and coating the goods were their daily routines. With a great service of Mr. Zafar Iqbal, I was able to finally reach the destination of ATM.

When the mirror was polished, I constructed the telescope mount and bought the PVC pipe for Optical Tube Assembly (OTA). This made my further task easy and I just fixed the mirror in the mirror cell and installed it in the optical tube without constructing every part from start. Hence 6″ Newtonian project completed with a lot of success.

My first observation from that 6″ Newtonian was at 7:00 PM Jupiter and Moon on 10/01/2011 (the date of my birthday). Next day I took the scope with me to my school, showed it to teachers, staff and Principal. The Principal asked me arrange a small program that day in the evening to observe Moon and Jupiter. That event became popular throughout the college.

In other words I can say that firstly due to countless blessings of Allah, and secondly due to Sir Ali Khan, Sir Umair Asim and Mr. Zafar Iqbal, I am able to achieve the goal of completing my telescope. I am heartly thankful and grateful to all of them because I think I would never be able to call myself a “Telescope Maker” without their great help. Sir Umair Asim provided me eyepieces of various powers and an expensive Philips cam for Astro Photography. Sir Ali Khan sent me some other mirror blanks of the sizes 12″, 8″ and also the grinding material (grit). Mr. Zafar Iqbal coated my mirror though he remained very busy in his office but still he managed to get time for my work.

My next projects will be 8″ f/4 and 12″ f/4 Newtonian Reflector.

Video From merapassionpakistan.com