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*
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!
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
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.
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 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
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...
You have to slowly walk around the barrel as you move the mirror blank across the tool. Overhang the blank one third as you do the w stroke across the tool. This cuts the concave surface you want into the mirror blank. As you progress through the finer grits replace the w stroke with a slow rotation of the blank as you slowly walk around the barrel clockwise, one rotation per half walk around the barrel. Soon you will reach the Rouge polishing stage. Check your focal lenght often as you approach your desired focal length. Use a light bulb and a white cardboard set up next to the bulb. Wet the mirror and hold it facing the bulb and move it back until the bulb appears clearly reflected on the cardboard. Measure the distance. Carefully inspect the surface of the blank for scratches left over from the coarser grits. If any are found go back one grit grade and continue grinding. Once down to the final grit your blank should be clear. No haze anywhere. Then you pour your pitch Mat onto the tool and continue with the Rouge polishing. Continue until you can no longer find any scratches, haze, or any defects under a ten x magnifier. No flaws must remain. If over grinding has shortened your focal point below your desired point, simplely swap places of tool and blank and regrind with tool on top beginning at the last grit used. Use the same grinding method, walk around the barrel slowly rotating the tool , edge over edge one third. This will begin to flatten the mirror blank and extend the focal length again. Check the mirror blank throughly for scraches, hazing. Nothing more disappointing than getting your finished mirror back with scratches showing through your pricey aluminum overcoat. Remember. Clean, clean, clean before going on to finer gits of grinding power.. keep each grit far from each other to avoid contamination. One tiny piece of coarser grit can ruin your day. Before lifting off your mirror blank from the tool, be sure your hands are dry!! . I broke a ten inch mirror once from a slip because of wet fingers and hands...that size glass is heavy. This method discribed above will give you a spherical mirror surface. For a finer surface, consult online parabolic grinding methods to better the one eighth wave . Parabolizing a mirror is the final step before sending it off to be aluminized. Or leave it as is depending on the mirrors intended use. Spherical mirrors give wonderful views of the planets, moon if the focal length is left ten times the mirrors diameter. Parabolic mirrors give fantastic views of deep stellar objects. Have fun!
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.!!!
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.
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.
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/
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.
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.
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.
Hi Mr. Arvind. I'm starting build mine too. As of now I'm trying to understand how lenses and Newtonian telescope works, while doing that I'm also thinking of alternatives as abrasives for grinding the mirror. I find sand a good one as we have bunch of sand here for construction purposes, but I don't think I can reach the 2000grit something by just using my mother's marble mortar pestle and also time consuming. So my solution to have a shiny surface will be once I almost reach the curve to make it parabolic using fine sand, I will use some low grit sandpaper like 500 until the previous scratches are shallow enough for 2000 to make it shiny enough to polish. Am I doing it right??? LOL I saw some dudes doing it to their car headlights, I hope it also work the same to glasses. Based on what I read, the ideal size of the mirror for beginner builders like me is 20cm diameter. If I succeeded then I will do the biggest I can make since I pretty much know how the telescope works and made. The glass type I'm gonna use is tempered one tho. Please tell me if it's wrong to use. Btw I'm living near the equator and seeing a blue sky is just a normal day to us so not that much particles that might affect the image quality, we live in 3 storey house and I find the terrace boring having one gives people around here sth fun to look at. The eyepiece part is really bugging me. As of now I have a very blur idea how it works. I hope I can make an improvised one for my mirror or else I'm going to be forced to buy one. Don't wanna spend as much as possible. But anyway I'm documenting the whole progress from scratch, If lucky that succeeded I will share it so everyone can do theirs too to see what's up in there and ofc out of available materials we have. Sorry for long comment.
Excellent simple video, can u please give details of subtances and procedure on how to silver the polished mirror like vinaya did in video ... thanking u
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..
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! :)
@@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.
Sir, thank you for sharing such a valuable information. Sir,can you suggest me whether a chromed surface can do as a mirror. What can be possible shortfalls.
Dear sir,Will you tell me which is the best focal ratio for 6 inch,8 inch,10 inch mirror blanks for home made reflecting type Newtonian telescope?what is the best thickness for mirror blanks?And which side i should silvering? Arvind Patel(Gujarat)
This is a gem. This is what youtube was meant for
Молодцы какие девчонки, в каждой бы школе так
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.
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
I am so impressed by your skill and resourcefulness. Have always wondered how this was done by hand. Brilliant, thanks.
I read about this over 50 years ago but had never seen it demonstrated. It is simpler than reading about it. Thank you.
Extremely informative video. I hope you will upload more telescope making video in time.
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 !!
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 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 :)
I am a physics faculty used to teach students of class XI & XII.
I must say, it is a very useful and informative video.
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
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
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.
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 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
I can listen to this guy all day! I love the Indian accent!
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
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 is fascinating & my respect sent to anyone who makes their own lenses by hand . Thank you very much .
Thanks for your comments
You have to slowly walk around the barrel as you move the mirror blank across the tool. Overhang the blank one third as you do the w stroke across the tool. This cuts the concave surface you want into the mirror blank. As you progress through the finer grits replace the w stroke with a slow rotation of the blank as you slowly walk around the barrel clockwise, one rotation per half walk around the barrel. Soon you will reach the Rouge polishing stage. Check your focal lenght often as you approach your desired focal length. Use a light bulb and a white cardboard set up next to the bulb. Wet the mirror and hold it facing the bulb and move it back until the bulb appears clearly reflected on the cardboard. Measure the distance. Carefully inspect the surface of the blank for scratches left over from the coarser grits. If any are found go back one grit grade and continue grinding. Once down to the final grit your blank should be clear. No haze anywhere. Then you pour your pitch Mat onto the tool and continue with the Rouge polishing. Continue until you can no longer find any scratches, haze, or any defects under a ten x magnifier. No flaws must remain. If over grinding has shortened your focal point below your desired point, simplely swap places of tool and blank and regrind with tool on top beginning at the last grit used. Use the same grinding method, walk around the barrel slowly rotating the tool , edge over edge one third. This will begin to flatten the mirror blank and extend the focal length again. Check the mirror blank throughly for scraches, hazing. Nothing more disappointing than getting your finished mirror back with scratches showing through your pricey aluminum overcoat. Remember. Clean, clean, clean before going on to finer gits of grinding power.. keep each grit far from each other to avoid contamination. One tiny piece of coarser grit can ruin your day. Before lifting off your mirror blank from the tool, be sure your hands are dry!! . I broke a ten inch mirror once from a slip because of wet fingers and hands...that size glass is heavy. This method discribed above will give you a spherical mirror surface. For a finer surface, consult online parabolic grinding methods to better the one eighth wave . Parabolizing a mirror is the final step before sending it off to be aluminized. Or leave it as is depending on the mirrors intended use. Spherical mirrors give wonderful views of the planets, moon if the focal length is left ten times the mirrors diameter. Parabolic mirrors give fantastic views of deep stellar objects. Have fun!
this was a grate video, thank you for posting it - cant wait to try it with the kids
grate video lol...puns
thanks
I'm not seeing the two daughters bouncing out to the club anytime soon. Lots more grinding left to do.
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.
Good video. Thank you for taking the time to make it.
I love the music from twin peaks
amazing work .. by you guys.. i am also going to buit my 8" telescope.
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.
An indian tutorial as always GOD DAMMIT
Thank you and your students for making this informative video , good luck with your skywatching .
That's fantastic . Paranjape Sir is always great.
This is why America is behind in science and math, I would have loved this on school
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.
Thank you for sharing this amazing Technique to prepare primary mirror.
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...
Great video. Back to basics method for creating a telescope. loved it
I've been wanting to make my own for years gonna have a go after watching this
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
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.
@@paranjpye is the second mirror for focusing flat?
@@josephdoherty7394 yes it is a flat mirror
And it's... Badalamenti! ❤️
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.
very interesting video
security And TV thanks
This looks so fun..much respesct ty sir from USA. ❤
Thank you so much for this beautiful video.
Very informative
I am trying to create a telescope myself and this was a great help.
From where do you source the glass blanks in India? Also is there any supplier that aluminise the polished mirrors?
I feel like this guy is explaining to me how to achieve the avatar state.
What a classic 👏🏼
Nice interesting work👍👍👍👍👍👍
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.
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
afarin, besyar besysr khoob bood👍
What an excellent documentary, thanks for your time
Good tutorial to learn making of Telescope mirror ..
excellent video sir
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.
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
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/
WOW THAT IS AN AWESOME LECTURE
thanks very much
thank you - nice simple explanation
you guys competed with big industry vacuum chambers and such
How so Joseph Jones -
Dr Joseph K Jones Ph.D struggling with English.
This is very good.... Thank you
Is it ok to use silver nitrate for silvering mirror? I heard it can be dangerous.
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
Focal length check...that is a cool technique!
This show is good for class
Great work Arvind...
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!
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/
A very good video.
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.
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
Hi Mr. Arvind. I'm starting build mine too. As of now I'm trying to understand how lenses and Newtonian telescope works, while doing that I'm also thinking of alternatives as abrasives for grinding the mirror. I find sand a good one as we have bunch of sand here for construction purposes, but I don't think I can reach the 2000grit something by just using my mother's marble mortar pestle and also time consuming.
So my solution to have a shiny surface will be once I almost reach the curve to make it parabolic using fine sand, I will use some low grit sandpaper like 500 until the previous scratches are shallow enough for 2000 to make it shiny enough to polish. Am I doing it right??? LOL I saw some dudes doing it to their car headlights, I hope it also work the same to glasses.
Based on what I read, the ideal size of the mirror for beginner builders like me is 20cm diameter. If I succeeded then I will do the biggest I can make since I pretty much know how the telescope works and made. The glass type I'm gonna use is tempered one tho. Please tell me if it's wrong to use.
Btw I'm living near the equator and seeing a blue sky is just a normal day to us so not that much particles that might affect the image quality, we live in 3 storey house and I find the terrace boring having one gives people around here sth fun to look at.
The eyepiece part is really bugging me. As of now I have a very blur idea how it works. I hope I can make an improvised one for my mirror or else I'm going to be forced to buy one. Don't wanna spend as much as possible.
But anyway I'm documenting the whole progress from scratch, If lucky that succeeded I will share it so everyone can do theirs too to see what's up in there and ofc out of available materials we have.
Sorry for long comment.
Good stuff guys
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 ..
Excellent simple video, can u please give details of subtances and procedure on how to silver the polished mirror like vinaya did in video ... thanking u
I have misplaced the silvering formula - I will check and shall get back to you
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..
Awesome video, good job to everyone involved. Really inspiring to see hand-made equipment!
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
I like what's on the building at Stellafane;
"The Heavens declare the glory of God"
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.
respected sir thanks for precious knowledge
I love the twin peaks music at the end
Dear sir please reply, What would be the segitta of a 12inch mirror??
A lovely tutorial... Thank you all
Sir, thank you for sharing such a valuable information. Sir,can you suggest me whether a chromed surface can do as a mirror. What can be possible shortfalls.
I think the chrome plating is done on the metal only.
very incormative thank you
"The object you see behind in the background" WHERE?
sir , availability of required materials is quite a big problem in delhi,,, where to get the required material and what would be its estimated cost..
arijeet ray - we are trying to create resource of telescope making kit. please email me in about 4 to 5 weeks time
Arvind Paranjpye that would be very much appreciated! Count me in :)
Prof Somak Roy Chowdhury is young. When does the video had been created?
for me it is always gratifying to see women doing science. imagine what discoveries female perception will still be able to discover.
Agora vou fazer um telescópio 🔭 Vai dar certo? Provavelmente não, mas vou fazer.
in which step of make mirror, I can use sandblast?
Please tell me on which part should coat the mirror
How to make the polishing tool ? What is this black liquid. ? Thanks
Dear sir,Will you tell me which is the best focal ratio for 6 inch,8 inch,10 inch mirror blanks for home made reflecting type Newtonian telescope?what is the best thickness for mirror blanks?And which side i should silvering?
Arvind Patel(Gujarat)
Sir, What are the chemicals that used for the reaction
Is this anyhow possible to silver on top of any plastic surface? Please respond