He gave some very good information about removing his eye glasses. I have watched so many times as people try looking through binoculars while wearing their eyeglasses, which it totally un-necessary.
@@terryglenweaver Wasn't expecting a reply on 2 years old comment. Quite strange, because astigmatic eyes focus light differently in different planes. And bino lens focus light similarly in all planes perpendicular to the lens.
Fantastic video. Very nice to see an India video from IUCAA India on a science which has rich traditions in India. I currently own a Skywatcher 8" and have owned quite few smaller ones since my school early college days and all my own pocket money !! My daughter too enjoys this hobby whenver I now get the chance to set it up and watch the skies from my busy daily life and job !! Great video have subsribed for more such good videos !!
What Is Islam? Islam is not just another religion. It is the same message preached by Moses, Jesus and Abraham. Islam literally means ‘submission to God’ and it teaches us to have a direct relationship with God. It reminds us that since God created us, no one should be worshipped except God alone. It also teaches that God is nothing like a human being or like anything that we can imagine. The concept of God is summarized in the Quran as: { “Say, He is God, the One. God, the Absolute. He does not give birth, nor was He born, and there is nothing like Him.”} (Quran 112:1-4) Becoming a Muslim is not turning your back to Jesus. Rather it’s going back to the original teachings of Jesus and obeying him
@@chnacr3992 Genesis claims earth created before sun also If religious texts were to be scrutinized by editors and publishers, they would be categorized as *fiction*
NICE! Really economical, and delivery is professional. Thanks so much. Of course, I speak in the name of the "Movements" of the 21st Century. Basically: search for Higher Power (secret name of such movement, and separate oneself movement.). Again, Good job. Complete, within all's means, as well as not verboise. Praise to YOU all, and secret name of [your] Higher Power.
I have read, that after grinding, the shape of the mirror is spherical. Because one needs parabolic mirror, there should be additional grinding at the rim. This kind of putting the reflective coating is relatively easy to make for people like me. Otherwise, there are other methods using evacuated vessels. Thank you for sharing :)
Dear Mr. Arvind, I am delighted after seeing this video. Thank you for posting it, thank you for doing what you do, and thank you for being who you all are. It is refreshing and encouraging to see female students involved in science and astronomy. I intend to check the availability of carborundum powder, as well as the basic glass disc blocks here in Israel, but I feel much more confident that I can do it and, hopefully, get my bright grandson (with the Angry Birds hat in the picture) interested in astronomy. A heartfelt thank you to you and your great team. Great work!
This was another great video on the path to building my own reflecting telescope. Accent and all, I was able to interpret the information presented. Thank you, Mr. Arvind Paranjpye and your student for taking the time to share this knowledge Well done. Bobbym59
This is an excellent video. Thank you for posting. You use slightly different methods than I use. I learned something watching your video. I hope that the young ladies are enjoying their telescope.
+Francis OReilly - sorry for the late reply - could you tell me your method - or what the difference? This video is made some 20 years ago - one of the young ladies is a professor of astronomy and the other one staying in Landon doing community services
Great work sir. I made refracting digital telescope but not astronomical. Since than I am searching to build reflecting one. Thanks a lot. I thought no one build such thing in india.!!!
Dear Sir Arvind, this is a very inspirational video for an astronomy student like me to create a telescope from scratch. It would be immensely helpful if you could guide me through the entire procedure. Once again, thanks a lot for the video
Excellent, I am glad you're teaching (young) people to do this. Working with the hands, and these kinds of skills need to be promoted. You made silvering look easy, I am almost tempted to give that a try.
This is a very interesting video... Great work! By the way, a well calibrated spherometer will guide you towards your goal radius of curvature regardless of the sunlight test. It's good to do both tests anyways... but the spherometer, if small enough, will give you the different radii of curvature of each point of the surface. That way you can tell how the curvature changes along the surface, giving you an idea of the surface figure while grinding... Quite enlightening...
This was very informative and interesting to watch. It was good to see the girls learning these skills. One question I have. The silvering process seemed to result in a kind of blotchy and dull surface. Can the surface like this be used in a telescope? Mirror surfaces are normally quite uniform and reflective.
Dear sir, I visited IUCCA when I was in 9th std, our school visit, it was v inspiring indeed to see the institute and the newton's apple tree in the garden 🙏🙏 I am planning to make my 1st telescope I have RC8 inches by GSO at the moment but want to make my own, will surely ask questions if I am stuck...
Hello... I will be visiting India at the end of May-through August of this year. Would love to visit your facility to learn and help with instruction. I will be in touch in the next next month.... Best regards, John Lightholder
Hi John - would be a pleasure to meet you. Please do send me your itinerary at paranjpye.arvind@gmail.com Let us see if we can spend some time together Arvind
Do I understand correctly that both your glass blanks begin flat? That there is no "form" to polish against? Is the profile a natural consequence of the grinding technique? Thank you for the video.
Liam Howlett - yes we begin with both blanks flat. And the top blank gets concave shape and the bottom one gets (we call it a tool) convex shape as a result of grinding.
yes it is. thanks for this comment of yours. and even greater satisfaction is when you see smile on face of a person whom you helped making his or her telescope.
Great instructional video. thanks!!!! But I think what you said at 15:42 is not correct. You cannot just leave a telescope for others to view Venus (or any other celestial object) unless you it fitted with have some type of autonomous motor drive system.
I have a 12 primary mirror from celestron which needs recoating, but nobody in my country is qualified. How do I proceed with removing the old oxidized aluminium coat an putting a new silver coat. Can you advice ? Else I will have to buy a brand new telescope..
@@Ho1yhe11 ..When I saw off aluminium pipes, some dust aluminum granules are produced...If I collect them in good quantities, can I use it as a substitute for Carborundum / Carbonundrum. . .to grind/polish the glass? 🤔
@@A.Netizen.Since.2010 yes if you cause the powder to oxidize first... aluminum itself is not as hard as its oxidized form. Though you will also run into the issue of grain size. I guess I should also mention that the purity of the aluminium also matters some alloys will form other things.
Hello Sir... My telescope primary mirror has been damaged by fungus. Can I clean that up by any way, or can you guide me in clearing up the old faulty mirror and re aluminized
Your comment caught my attention, because the aluminized is supposed to last a lifetime and doesn't deteriorate. However, the silver plating of the mirrors -it's a fairly simple chemical process that you could do in your kitchen- does deteriorate over time because an oxidation process occurs in contact with the air. Are you sure your mirror is aluminized?
@@conceptodaf Sir, I am confused since I am unable to determine if the primary mirror is aluminized or not. But it is a reflector telescope and the primary mirror has been damaged by fungus. If you can help I can send you images of the primary mirror
Twin Peaks theme son? Hah! Watch what channel your audio is in, it should always be 50/50, not in one ear only. Btw, kudos for sending out carborundum and silver nitrate to randoms who can't get it. That level of charitable acts to spread the enlightenment that science brings is essential for all of us to uphold.
manvi and vinaya among both astronomers , the check-shirt one. ... I want to say... I like you ... and as i am new bignr astronomer, i want to learn how to make telescope from you... please guide me... be friends! :)
If Indians can do it I am sure cowboys can do it too! No that was just a light hearted joke, but how excellent you guys in your non-high tech managed to achieve such a brilliant Mirror making and now I must have a go too, and that mirror layer using some chemicals was easy as I thought one needed a vacuum chamber to deposit aluminium coating, mind you the thrills you get when you make your own telescope from scratch including your own have base ( which is based on Dobsonian telescope) is beyond this world. Very well done to show how simple it really can be, but of course you have to put hours of grinding work.
Thanks for your comments and for the clarification that "If Indian....." that it was a light hearted joke - it was rather hitting below the belt as they say. Please see my link sites.google.com/site/diy100atm/ where we have explained making of mirror with 100 mm dia. One can start observing, say moons of Jupiter in just about 6 days time. There are a few astronomical institutions in India from where amateur astronomers can get their mirrors aluminized FREE.
Arvind Paranjpye Mr Arvind! I hope it didn't hurt too much below the belt! (LOL) , that was my humour, I consider myself as a cowboy! hence my remarks if Indians can do it, sure enough should not be a problem for me!! Now on a serious matter, where would I get this grinding stuff from, what sort of shops or outlets sell this kind of stuff, i am based in UK, so it should be I am sure more easily obtainable here in the West, and I am sure obtaining Nitric Acid and other chemicals wouldn't be easy due to strict regulations, but I am sure I would be able to get a small quantity from some where. However, could you please tell me why we need to use Nitric acid, since you wash it off afterwards, is it really needed? Can I omit the Nitric acid process as I am trying to do it the cowboy way! The Mirror coating how thick is this coating, and how many times can it be cleaned with care when the reflector gets dirty in use. Thanks in advance.
samdomding Hi! A very happy new year to you -- and sorry for the delayed reply. Indeed yes it did hurt me Initially but your comments are taken in the right spirit. We learn to make telescopes from Europe (UK and France) and also from US. My suggestion is check with your local planetarium - they will be able to tell you where to get the stuff from - or they may direct you to someone (most likely some amateur astronomers) who can help you. It is best to get mirrors aluminized. This can be done almost free of cost at physics laboratories - or at astronomical observatories. Like in India we have a few professional institutions where an amateur astronomers can get their mirror aluminized free of cost. this is because most observatories have a chamber for aluminize their mirror but the requirement is once in year or so. But to keep the chamber running they would 'test fire' it on regular basis. At that time you can get your mirrors aluminzed from them. The flip side is you have to wait but the added advantage is the coating is done by pros and is very good quality (apart from being free).
RAJ M If you think the video is at least 50 years old - you give me undue credit - at age 6 I would not have done such a thing - and at that point in time colour filming was far too expensive
can you tell me how to determine what your Sagitta should be i have an 8.5 inch blank i am going to be working with thank you for sharing your time with us.
sagitta will depend on the focal length (or f - ratio ) of your mirror please check this link - I have put an link to xls for calculating sagitta basic design | diy100atm or try this www.atmsite.org/contrib/Prewitt/sagitta/
Very nice, Sir! I live in Bangalore, and I've been wanting to build a telescope, but I can't seem to find any shops selling parabolic mirrors, I'd love to make one, but I don't have the resources. And the focussers are hard to come by here too. I could buy a telescope but the good entry level ones are costly. Great video!
I would like to suggest you that first make one small 100 mm one - get hang of grinding - then you can go for the next step. Please visit sites.google.com/site/diy100atm/ for detail on making a reflecting telescope. BTW - you may go to the Bangalore Planetarium. There is very active group making telescope. They can help you. And of course feel free talk to me.
This is a gem. This is what youtube was meant for
Respect! Thats the spirit of John Dobson and amateur (!) telescope making. Thanks.
I keep thinking of Laura Palmer. This is the first time I've seen the chemical deposition of silver to create the mirror surface.
Extremely informative video. I hope you will upload more telescope making video in time.
I read about this over 50 years ago but had never seen it demonstrated. It is simpler than reading about it. Thank you.
He gave some very good information about removing his eye glasses. I have watched so many times as people try looking through binoculars while wearing their eyeglasses, which it totally un-necessary.
except when your eyes are astigmatic.
@@yashsvidixit7169 both of my eyes are, yet I can properly adjust binoculars that I do not need my glasses.
@@terryglenweaver Wasn't expecting a reply on 2 years old comment. Quite strange, because astigmatic eyes focus light differently in different planes. And bino lens focus light similarly in all planes perpendicular to the lens.
Wow, it's rare that I actually watch a video twice in a row, but I'm watching this one again.
J R's Place do let us know when you make your telescope
Молодцы какие девчонки, в каждой бы школе так
Fantastic video. Very nice to see an India video from IUCAA India on a science which has rich traditions in India. I currently own a Skywatcher 8" and have owned quite few smaller ones since my school early college days and all my own pocket money !! My daughter too enjoys this hobby whenver I now get the chance to set it up and watch the skies from my busy daily life and job !! Great video have subsribed for more such good videos !!
I am so impressed by your skill and resourcefulness. Have always wondered how this was done by hand. Brilliant, thanks.
15:11 "for those who are spectacular like me" hahaaaa, great one
+locoexpo Whaha xD
Thát is a good one :')
What Is Islam?
Islam is not just another religion.
It is the same message preached by Moses, Jesus and Abraham.
Islam literally means ‘submission to God’ and it teaches us to have a direct relationship with God.
It reminds us that since God created us, no one should be worshipped except God alone.
It also teaches that God is nothing like a human being or like anything that we can imagine.
The concept of God is summarized in the Quran as:
{ “Say, He is God, the One. God, the Absolute. He does not give birth, nor was He born, and there is nothing like Him.”} (Quran 112:1-4)
Becoming a Muslim is not turning your back to Jesus.
Rather it’s going back to the original teachings of Jesus and obeying him
@@ahmdabdallah5811 "God is nothing like a human being". Quite right. The most obvious difference being that human beings exist.
@@ahmdabdallah5811 What is Islam? It says that the Earth was created before the stars and that the Sun revolves around it
@@chnacr3992
Genesis claims earth created before sun also
If religious texts were to be scrutinized by editors and publishers, they would be categorized as *fiction*
I am a physics faculty used to teach students of class XI & XII.
I must say, it is a very useful and informative video.
I can listen to this guy all day! I love the Indian accent!
NICE! Really economical, and delivery is professional. Thanks so much. Of course, I speak in the
name of the "Movements" of the 21st Century. Basically: search for Higher Power (secret name of such movement, and separate oneself movement.). Again, Good job. Complete, within all's means, as well as not verboise. Praise to YOU all, and secret name of [your] Higher Power.
I have read, that after grinding, the shape of the mirror is spherical. Because one needs parabolic mirror, there should be additional grinding at the rim. This kind of putting the reflective coating is relatively easy to make for people like me. Otherwise, there are other methods using evacuated vessels. Thank you for sharing :)
Dear Mr. Arvind, I am delighted after seeing this video. Thank you for posting it, thank you for doing what you do, and thank you for being who you all are.
It is refreshing and encouraging to see female students involved in science and astronomy. I intend to check the availability of carborundum powder, as well as the basic glass disc blocks here in Israel, but I feel much more confident that I can do it and, hopefully, get my bright grandson (with the Angry Birds hat in the picture) interested in astronomy.
A heartfelt thank you to you and your great team. Great work!
Thanks Aharon Konforti - for your comments. Do let me know if you need some help in getting the carborundum powder
This was another great video on the path to building my own reflecting telescope.
Accent and all, I was able to interpret the information presented.
Thank you, Mr. Arvind Paranjpye and your student for taking the time to share this knowledge
Well done.
Bobbym59
Good video. Thank you for taking the time to make it.
This is fascinating & my respect sent to anyone who makes their own lenses by hand . Thank you very much .
Thanks for your comments
That's fantastic . Paranjape Sir is always great.
this was a grate video, thank you for posting it - cant wait to try it with the kids
grate video lol...puns
thanks
An indian tutorial as always GOD DAMMIT
This is why America is behind in science and math, I would have loved this on school
This is an excellent video. Thank you for posting. You use slightly different methods than I use. I learned something watching your video. I hope that the young ladies are enjoying their telescope.
+Francis OReilly - sorry for the late reply - could you tell me your method - or what the difference? This video is made some 20 years ago - one of the young ladies is a professor of astronomy and the other one staying in Landon doing community services
Help me to make
Great work sir. I made refracting digital telescope but not astronomical. Since than I am searching to build reflecting one. Thanks a lot. I thought no one build such thing in india.!!!
+Brajesh Rai -- thanks. I would like to know what is your digital telescope
Arvind Paranjpye its a refractor with modified USB camera connected with computer that displays magnified video or still image of object.
+Brajesh Rai have you explained it somewhere ? if yes - please send me the link else you should put it at some site
Arvind Paranjpye I didn't explained it any where but will send you through email if you wish. It is simple project. Glad to share with you.
amazing work .. by you guys.. i am also going to buit my 8" telescope.
Dear Sir Arvind, this is a very inspirational video for an astronomy student like me to create a telescope from scratch. It would be immensely helpful if you could guide me through the entire procedure. Once again, thanks a lot for the video
Thanks for your comments and appriciations
I'm not seeing the two daughters bouncing out to the club anytime soon. Lots more grinding left to do.
Great video. Back to basics method for creating a telescope. loved it
Excellent, I am glad you're teaching (young) people to do this. Working with the hands, and these kinds of skills need to be promoted. You made silvering look easy, I am almost tempted to give that a try.
David Henderson - I teach anyone one who is interested - please give it a try - silvering has become a bit too expensive but it is worth a try -
This is a very interesting video... Great work! By the way, a well calibrated spherometer will guide you towards your goal radius of curvature regardless of the sunlight test. It's good to do both tests anyways... but the spherometer, if small enough, will give you the different radii of curvature of each point of the surface. That way you can tell how the curvature changes along the surface, giving you an idea of the surface figure while grinding... Quite enlightening...
Thank you and your students for making this informative video , good luck with your skywatching .
This looks so fun..much respesct ty sir from USA. ❤
Thank you for sharing this amazing Technique to prepare primary mirror.
You really are spectacular sir :-p !!! Nice Vid!
Siddharth Anvekar haha i though I am the only one who noticed it :)
Siddharth Anvekar Ha Ha I said so
Arvind Paranjpye sir i need your help
Nice interesting work👍👍👍👍👍👍
I will continue my a mature research with this video. Thank you very much guys! Omg! You answered all my questions.
Bro what the name a material ini 9:20
@@arfaberkahtv1065 it is Asphalt the material used to make roads.
i want to be a student of this respected man
+Farhaj Syed - I wonder what respected person you are referring too but you are welcome to nehru planetarium, mumbai
I want those girls to give me a "stroke."
+Donal Lour O_O
Farhaj Syed I know right!? I feel comfortable
@@DonalLour my God y'all are desperate lol
very interesting video
security And TV thanks
What an excellent documentary, thanks for your time
I've been wanting to make my own for years gonna have a go after watching this
I love the music from twin peaks
And it's... Badalamenti! ❤️
What a classic 👏🏼
Good tutorial to learn making of Telescope mirror ..
afarin, besyar besysr khoob bood👍
excellent video sir
Thank you so much for this beautiful video.
Very informative
I am trying to create a telescope myself and this was a great help.
I feel like this guy is explaining to me how to achieve the avatar state.
Good stuff guys
A very good video.
WOW THAT IS AN AWESOME LECTURE
thanks very much
This was very informative and interesting to watch. It was good to see the girls learning these skills. One question I have. The silvering process seemed to result in a kind of blotchy and dull surface. Can the surface like this be used in a telescope? Mirror surfaces are normally quite uniform and reflective.
This show is good for class
for me it is always gratifying to see women doing science. imagine what discoveries female perception will still be able to discover.
Great work Arvind...
This is very good.... Thank you
Dear sir, I visited IUCCA when I was in 9th std, our school visit, it was v inspiring indeed to see the institute and the newton's apple tree in the garden 🙏🙏 I am planning to make my 1st telescope I have RC8 inches by GSO at the moment but want to make my own, will surely ask questions if I am stuck...
Hello... I will be visiting India at the end of May-through August of this year. Would love to visit your facility to learn and help with instruction. I will be in touch in the next next month.... Best regards, John Lightholder
Hi John - would be a pleasure to meet you.
Please do send me your itinerary at paranjpye.arvind@gmail.com
Let us see if we can spend some time together
Arvind
thank you - nice simple explanation
Thanks to all of who have satisfied
my urge of knowledge for making
Telescope and the explaining the
Basic FUNDA.
Permanent Student of Science 👍
I like what's on the building at Stellafane;
"The Heavens declare the glory of God"
Focal length check...that is a cool technique!
Do I understand correctly that both your glass blanks begin flat? That there is no "form" to polish against? Is the profile a natural consequence of the grinding technique? Thank you for the video.
Liam Howlett - yes we begin with both blanks flat. And the top blank gets concave shape and the bottom one gets (we call it a tool) convex shape as a result of grinding.
@@paranjpye is the second mirror for focusing flat?
@@josephdoherty7394 yes it is a flat mirror
respected sir thanks for precious knowledge
It must be great feeling watching sky with handmade telescope
yes it is. thanks for this comment of yours. and even greater satisfaction is when you see smile on face of a person whom you helped making his or her telescope.
From where do you source the glass blanks in India? Also is there any supplier that aluminise the polished mirrors?
You make it look so easy. I might havd to give that a go. Brilliant job mate.
Thanks for your appreciation - let me know when you start working on your telescope ... all the best..
Arvind Paranjpye i will and i might ask for some help at some points lol. Il add a video to thank u
*****
please feel free to talk to me ..... most welcome ..
Awesome video, good job to everyone involved. Really inspiring to see hand-made equipment!
A lovely tutorial... Thank you all
How does this grinding method ensure that the glass will have a spherical surface rather than any other concave profile?
It doesn't ensure. That's why the Ronchi test is done. If test shows defects, then re grinding is done.
Great instructional video. thanks!!!!
But I think what you said at 15:42 is not correct. You cannot just leave a telescope for others to view Venus (or any other celestial object) unless you it fitted with have some type of autonomous motor drive system.
you guys competed with big industry vacuum chambers and such
How so Joseph Jones -
Dr Joseph K Jones Ph.D struggling with English.
Hello sir, where can i get these blank disks? or do you sell any of these disks already made? i'd like to build a telescope
you can get the glass blanks cut from glass vendors
I have a 12 primary mirror from celestron which needs recoating, but nobody in my country is qualified. How do I proceed with removing the old oxidized aluminium coat an putting a new silver coat. Can you advice ? Else I will have to buy a brand new telescope..
I loved the video! Great information!
Carbonundrum = silicon carbide = SiC
Notably corundum (aluminium oxide) will also work (hardness of 9)
Thanks for write
@@Ho1yhe11
..When I saw off aluminium pipes, some dust aluminum granules are produced...If I collect them in good quantities, can I use it as a substitute for Carborundum / Carbonundrum. . .to grind/polish the glass? 🤔
@@A.Netizen.Since.2010 yes if you cause the powder to oxidize first... aluminum itself is not as hard as its oxidized form.
Though you will also run into the issue of grain size.
I guess I should also mention that the purity of the aluminium also matters some alloys will form other things.
My great grandfather made one of these in the 20's. Still have some of the glass blanks. Not sure if I should try and use them. Don't want to mess up
solagish you should give it a try - it is a great fun and when done gives you very nice satisfaction. What is the size of the blank - Arvind
Messing up is part of the learning process.
Dear sir please reply, What would be the segitta of a 12inch mirror??
Beautifully done.
Hello respected sir I have a question " sir how many grit of carborundum is use in fine grinding?"
Sir please reply I also want this answer
Hello Sir... My telescope primary mirror has been damaged by fungus. Can I clean that up by any way, or can you guide me in clearing up the old faulty mirror and re aluminized
Your comment caught my attention, because the aluminized is supposed to last a lifetime and doesn't deteriorate. However, the silver plating of the mirrors -it's a fairly simple chemical process that you could do in your kitchen- does deteriorate over time because an oxidation process occurs in contact with the air. Are you sure your mirror is aluminized?
@@conceptodaf Sir, I am confused since I am unable to determine if the primary mirror is aluminized or not. But it is a reflector telescope and the primary mirror has been damaged by fungus. If you can help I can send you images of the primary mirror
I love the twin peaks music at the end
Twin Peaks theme son? Hah! Watch what channel your audio is in, it should always be 50/50, not in one ear only. Btw, kudos for sending out carborundum and silver nitrate to randoms who can't get it. That level of charitable acts to spread the enlightenment that science brings is essential for all of us to uphold.
Great souls walk this Earth! All is not lost, there is hope, thank G-d!
Haha I literally see you everywhere!
Spectacular 😂
in which step of make mirror, I can use sandblast?
excellent
super
document
Is it ok to use silver nitrate for silvering mirror? I heard it can be dangerous.
Thank you for posting. I found it most interesting,
manvi and vinaya among both astronomers , the check-shirt one. ... I want to say... I like you ... and as i am new bignr astronomer, i want to learn how to make telescope from you... please guide me... be friends! :)
Too late....she's mine
very incormative thank you
If Indians can do it I am sure cowboys can do it too! No that was just a light hearted joke, but how excellent you guys in your non-high tech managed to achieve such a brilliant Mirror making and now I must have a go too, and that mirror layer using some chemicals was easy as I thought one needed a vacuum chamber to deposit aluminium coating, mind you the thrills you get when you make your own telescope from scratch including your own have base ( which is based on Dobsonian telescope) is beyond this world. Very well done to show how simple it really can be, but of course you have to put hours of grinding work.
Thanks for your comments and for the clarification that "If Indian....." that it was a light hearted joke - it was rather hitting below the belt as they say.
Please see my link sites.google.com/site/diy100atm/ where we have explained making of mirror with 100 mm dia. One can start observing, say moons of Jupiter in just about 6 days time.
There are a few astronomical institutions in India from where amateur astronomers can get their mirrors aluminized FREE.
Arvind Paranjpye Mr Arvind! I hope it didn't hurt too much below the belt! (LOL) , that was my humour, I consider myself as a cowboy! hence my remarks if Indians can do it, sure enough should not be a problem for me!!
Now on a serious matter, where would I get this grinding stuff from, what sort of shops or outlets sell this kind of stuff, i am based in UK, so it should be I am sure more easily obtainable here in the West, and I am sure obtaining Nitric Acid and other chemicals wouldn't be easy due to strict regulations, but I am sure I would be able to get a small quantity from some where. However, could you please tell me why we need to use Nitric acid, since you wash it off afterwards, is it really needed? Can I omit the Nitric acid process as I am trying to do it the cowboy way!
The Mirror coating how thick is this coating, and how many times can it be cleaned with care when the reflector gets dirty in use. Thanks in advance.
RAJ M Which video ?
samdomding
Hi! A very happy new year to you -- and sorry for the delayed reply.
Indeed yes it did hurt me Initially but your comments are taken in the right spirit.
We learn to make telescopes from Europe (UK and France) and also from US. My suggestion is check with your local planetarium - they will be able to tell you where to get the stuff from - or they may direct you to someone (most likely some amateur astronomers) who can help you.
It is best to get mirrors aluminized. This can be done almost free of cost at physics laboratories - or at astronomical observatories. Like in India we have a few professional institutions where an amateur astronomers can get their mirror aluminized free of cost. this is because most observatories have a chamber for aluminize their mirror but the requirement is once in year or so. But to keep the chamber running they would 'test fire' it on regular basis. At that time you can get your mirrors aluminzed from them. The flip side is you have to wait but the added advantage is the coating is done by pros and is very good quality (apart from being free).
RAJ M If you think the video is at least 50 years old - you give me undue credit - at age 6 I would not have done such a thing - and at that point in time colour filming was far too expensive
can you tell me how to determine what your Sagitta should be i have an 8.5 inch blank i am going to be working with thank you for sharing your time with us.
sagitta will depend on the focal length (or f - ratio ) of your mirror
please check this link - I have put an link to xls for calculating sagitta
basic design | diy100atm
or try this
www.atmsite.org/contrib/Prewitt/sagitta/
Please tell me on which part should coat the mirror
Is this anyhow possible to silver on top of any plastic surface? Please respond
Very nice, Sir!
I live in Bangalore, and I've been wanting to build a telescope, but I can't seem to find any shops selling parabolic mirrors, I'd love to make one, but I don't have the resources. And the focussers are hard to come by here too. I could buy a telescope but the good entry level ones are costly.
Great video!
I would like to suggest you that first make one small 100 mm one - get hang of grinding - then you can go for the next step.
Please visit sites.google.com/site/diy100atm/ for detail on making a reflecting telescope.
BTW - you may go to the Bangalore Planetarium. There is very active group making telescope. They can help you. And of course feel free talk to me.
Arvind Paranjpye Yes, sure Sir! Thank you very much, I will contact you if I need any advice!
jamn610
sure - do contact me
You may try at Association of Bangalore Amateur Astronomers (ABAA)
abaaonline.blogspot.com.au/
How to make the polishing tool ? What is this black liquid. ? Thanks
Fantastic Arvind!!!
Prof Somak Roy Chowdhury is young. When does the video had been created?