Calvin here, planning to build a Newtonian Telescope

[8394aj1]

Guys can I build a Simple Newtonian telescope out of these available materials?

»Two 1.5cm thick and 20cm diameter plate glasses
»Two 14mm diameter with 10mm focal length small lenses(Can I use these as improvised eyepiece?)
»Small flat mirror for diagonal

Another question.
What's focal length can you guys recommend for 20cm plate glass?
I just wanna see the moon craters and Saturn/Jupiter if possible ;D

 

Hoping for informative replies. Cheers

[Dr_Ju_ju]

Hi,

Yes, it can be done, as a labour of love, search for a Dobsonian build, but to be honest polishing\mirroring you glass pieces my prove problematical, then the costs of the other mounting pieces etc....

[8394aj1]

Thanks for response Dr.

I've been reading stuff about building a diy telescope for a couple of weeks now. No actions yet aside from preparing the sand grits needed for grinding. I don't mind the mounting yet coz we have lots of woods here. For now I want a functioning scope.

Waiting for recommended focal length for my blanks.

[Stub Mandrel]

Hi Calvin,

Take a look here for everything you need by way of advice and guidance, including formulas so you can match your focal length to what you want to see.

https://stellafane.org/tm/

[8394aj1]

I've ran into that site before but I just bookmarked it and now in the bottom of my bookmark list. Thanks for pointing that one out. 

[hughgilhespie]

Hi Calvin,

It's quite a few years since I ground my 200 mm mirror but I would suggest you aim for a minimum focal length of 1200 mm, i.e. an f/6 mirror. It gets much harder to figure a mirror correctly if you try for a smaller focal length. If you went for f/8 or f/9 you do get a rather long telescope but this is good for planetary and lunar imaging with the big advantage that you will get away with making a spherical mirror - much, much easier.

I would recommend you try and get hold of the book by Jean Texereau, 'How to Make a Telescope'. It is very good and gives detailed instructions.

Hope his helps.

Regards, Hugh

 

[Glasspusher]

Have a look at my thread on grinding a 12 inch mirror, hopefully you might find it helpful. Good luck with your project.

 

 

 

 

John

[8394aj1]

Thanks for the replies, I feel satisfied and a lot confident now to do the initial steps of grinding. I also may ask if there's anyone here also grind their compound lenses for eyepiece?