starting out building a telescope...

[XR8beast]

Hi ppl , a couple of months ago I got a 4" newt for a present and it's a cheap and nasty from china , but it's got me hooked on star gazing and now I want a bigger apperture (8") . I bought this book called "Build your own telescope" by Richard Berry and now I want to have a go at building one myself, but I dont know where to source the glass blanks or the abrassives to make a mirror.I know people will try and tell me it's probably not worh making it but I get great satisfaction from making my own telescope from the ground up.I live in the Sydney , Homebush area can anyone point me in the right direction and maybe give us an approx price for the 2 glass blanks ....thanks .

[Exfso]

Here ya go, this guy just lives a couple of Km from me, he is the man to contact, has all the good stuff.

http://www.telescopes-astronomy.com.au/telescopes036.htm

[XR8beast]

thanks Exfso !! , appreciate the help :)

[iceman]

Hi XR8Beast!

:welcome: to the forum! :hi: How did you hear about us?

I'm not the "build your own telescope" kind, so I can't help you with the specifics, but I admire the patience and perseverence you'll need :)

There's a few ATM'ers on this forum (orion/cometcatcher/mhodson/vermin plus some others), so they'll no doubt be able to help you along your way.

Good luck with it, keep us posted with your progress and hope to see you back!

If you want to document (in words and pictures) your construction from start to finish, it would make a great "how-to" article on the IceInSpace site!

[XR8beast]

Hi Iceman !

I followed your link from a forum , I cant remember now :confused: . Anyway I just emailed the suppliers for some prices and I'll definately show the progress I'm making .A bit worring as this is my first attempt and more than likely I'll make a "how not to polish your mirror tutorial" , but I'm patient and good with my hands so I'll definatly let you know how it goes.

[RAJAH235]

Welcome XR8beast, You've picked a good size to start with. Have fun but take your time. One of our members ground his own 13" as his 1st project, (18 mths.in his spare time). :gday:
Just the facts m'am.

[mch62]

Hi XR8beast , glad to see another ATM on the forum.
The reward that you will get from doing it your self will be very satisfying .
I have ground 3 mirrors many years ago from 4"- 8"and my only advise for your first and as it is an 8" is to make it a longish focal ratio of at least f6 or more.
Even an f8 make a wonderful planetary scope and is still good for visual deep sky.
The slower light cone is also easier on cheaper eyepieces, so you don't have to go and get expensive ones starting out.
It is a lot easier to figure an f6 than say an f4.5 or 5 especially for your first.
Also if it is going to be a Dob , you will want the eyepiece at a reasonable height .
i have included a link to a very popular program for ray tracing a Newtonian's optics.
Read the Help files , mainly "notes on design".

http://home.att.net/~dale.keller/atm/newtonians/newtsoft/newtsoft.htm

Happy grinding Mark

[Orion]

Hi XR8beast, and welcome it certainly is very rewarding making the telescope your self and I would go with everything mhodson told you especially with the long focal ratio mirrors.
The hardest part of optical design would have to be the figuring of the primary mirror.
I think the best way to go for your first telescope would be the Dobsonian design with a Alt/Az axis.
Be warned you will suffer from apeture fever after your fist telescope. :)
In any case we are here to serve and any questions you may have we'll be glad to answer.
:work: :astron:

[XR8beast]

Hi guys , does anybody know if clubs offer courses in mirror making in Sydney ? . This is harder than it looks !

[Vermin]

Can't help with the local clubs, but these guys have a lively discussion going on mirror grinding:

http://www.starastronomy.org/cgi-bin/wwwthreads/postlist.pl?Cat=&Board=atm

[Orion]

Hi XR8beast it might be an idea to buy the primary and secondary mirrors that way you don’t have to worry about figuring or coating them. BinTel in Sydney sell a range of mirrors beside other ATM stuff that you might need in building your telescope.

But if you still want to go ahead with grinding and polishing here is a web sight you’ll be interested in.

http://www.stellafane.com/atm/atm_mirror/atm_mirror_overview.htm

[gbeal]

I'm with Ed,
I did actually grind a 6" as a teenager, but unless it is really what you want to do, I would forget it. (just my $0.02cents worth though).
To my mind you are better off buying an optical set, perhaps an 8" or 10" and constructing the rest.
As Ed said, Bintel seem to sell them, as do a company called Antler (or whatever) Optics, they advertise on the Gecko Optical group.
Gary

[Vermin]

If you want to buy Australian and want the best optical quality, send an email to Mark Suching:

http://deepsky.cia.com.au/optics/

[XR8beast]

Ok thanks heaps guys , you have been a big help , so I'll take the good advice and buy the optics.

[rmcpb]

Welcome to the madness XR8beast - look forward to the photo that goes with that name.

I agree about buying the optics. I have made scopes before and found the idea of grinding the optics too much to handle. There is enough in designing and constructing the rest to keep any person going without sending them mad. One day I will have to grind a mirror just to say I have done it though.

Cheers

[XR8beast]

I got a few ideas on what materials to use in the telescope construction so far. I'm a plumber by trade so I have a fair idea on what certain material expansion rates are and what resists heat best. I'm particualrly interested in ABS pipe and fittings as it is very light and extremely strong with a low expansion rate. Any of you guys familiar with ABS ?

[iceman]

Hey that's not too bad! Looks like a pretty good price.. Saxon aren't too bad. I'm not sure about the eyepieces and especially the barlow, looks like a 3x which will most likely be terrible.

Also the eyepieces, the 25mm will be the best.. maybe the 12 will be ok for planetary and lunar. The 4mm will be junk, I can guarantee it.

The motorised mount looks ok, the mount might be a bit wobbly when it's chugging along, especially in a bit of wind, but you could probably hang a brick off it to make it a bit sturdier.

How much is postage? For $399 + $50 postage you could've got an 8" dob which would be much better quality, and obviously a bigger mirror. But if you're planning on building your own 10" dob, then it's probably going to be quite an adequate scope to start you out and get you hooked!

You just might need to invest in a few cheapish eyepieces, like some better quality plossls or maybe the GSO SV eyepieces. The good thing about that, is you'll be able to use them in your next scope too.

Let us know how it performs when it arrives!

[rmcpb]

OK for us plebs, what's ABS?

Cheers

[iceman]

doh he removed the link to the scope he bought off ebay, now my post looks out of place! :)

[XR8beast]

Here is some info on ABS , namely DURAFLOW. The only drawback I see is probably the bonding solvent used. It's has a very strong odour when I have used it and it's very strong aswell . We apply a cleaning fluid first (this is the strongest) , then paint on the grey solvent with a brush.The pipe is somewhat waxy but it sands easily and the wall thickness on say an 8" pipe is almost 20mm.Here is a link to some PDF files :

http://www.tycowater.com.au/water/products/plastic_pipeline_systems/plastic_products#ABSDuraFree

P.S. Sorry about the missing post iceman , here it is again :

http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=6154065717&ssPageName=ADME:B:BN:AU:1

[ballaratdragons]

Hi XR8,

Add up the cost of Primary and secondary mirrors, 2 Mirror cells, spider, focuser, finderscope and finder mount, materials for the dob mount, eyepieces, etc. etc.

It comes to quite a lot.

You can buy a very good quality 10" Dob for $649 including eyepieces.
Saves time building and more time in the sky!

If you still want to make your own, like some of us in here have done, make it on the nights when you are not viewing through the bought one.

:P

[XR8beast]

Yeah good point I know , but it's just that bit more speacial when you know you made it with your own two hands (appart from the secondary mirrors, 2 Mirror cells, spider, focuser, finderscope and finder mount, materials for the dob mount, eyepieces, etc. etc.)thats all :P

[ballaratdragons]

I know exactly what you mean!!!!

The first scope I made 20 years ago was a 4.25" reflector in a 6"PVC Sewerage tube with a 1" & 1.25" PVC sliding focuser, 2" PVC finder, PVC mounts and Gal pipe German EQ mount.

A total piece of crap with very good views!
Unfortunately I sold it in a Garage sale when I moved.


I WANT IT BACK!!!! I made it.

At least I still have the 3.5" refractor I made. Not excellent but it works o.k.

Yes you are right, there is satisfaction doing it yourself.

Even though I bought my current 12", I have made a quickfinder for it from PVC. Works good.

I wait for your construction reports.

[rumples riot]

I think that grinding a mirror has its own rewards, however, you will have make the grinding surface out of the spare blank, then a focult tester and then get it coated. This is a lot of hard work and does take some time to get right. That said though, hand ground mirrors usually are better than machine ground mirrors. Just bear in mind that making you own scope can be a long process. I did it once took 7 months before everything was up and running. That was including the German EQ mount with worm drive.

My advice is buy the optics and build the rest. Much less time involved and you can see everything come together quickly.

Anyway just my two cents worth.

[Orion]

Yes, and fill us in on your progress:thumbsup:

[rmcpb]

How's the project going XR8??

[asimov]

Hi & welcome fellow ford fan.

After building my own 8" reflector some years ago, including making the main mirror, I wouldn't bother these days. I would definately make everything except the mirror though....much cheaper. I feel the prices of mirror's to buy are well worth the money.

I spent at least 3 months making the mirror & the testing equipment. The end result was a pretty crappy mirror...had a turned down edge & we didn't polish it properly. One of the most frustrating things was getting one piece of 80 grit in the 120 grit grinding......GRRR!.. I ended up selling the mirror & buying a replacement.

I'm not trying to talk you out of making your own by any means! I commend you for having a go.

Good luck.

Asimov

[ausastronomer]

Hi XR8,

There is another option available to you and its a great way to go for a 1st time scope builder and "mirror maker".

Having someone to call on for advice makes things a lot easier, an experienced telescope/mirror maker called Ron Royle runs a "Build Your Own Telescope Workshop" at Sydney Observatory. The cost is about $900 which covers all the tuition, guideance and materials to build a complete 8"/F7 dobsonian. The course runs 1 night per week for 3 hours for 8 consecutive weeks. For a 1st time builder this is a great way to go, Ron is very experienced and its "worth millions" to have someone standing by to call on all the time.

http://www.telescopes-astronomy.com.au/telescopes033.htm

Here is a link to the kits Ron uses which are supplied by Mathew Lovell from Telescopes and Astronomy.

I couldn't actually find the link to Ron's webpage on the Sydney Observatory website so maybe its worth giving them a call on (02) 9241-3767 and asking them if Ron Royle still runs those courses. Maybe he now runs them privately and not in conjunction with Sydney Observatory. I know he ran them 2 years ago and ran them for 10 before that. Also Don Whiteman at the Binocular and Telescope shop may also be able to tell you if Ron is still doing those courses. Failing that I can ring Ron for you (I have his number somewhere) and ask him if/when he is going to run the next course if your interested ?


CS-John B

[asimov]

Heres a pic of my 12.5" Everything made by me except the optics. [Parks] Total cost? About 3 grand...[plus 2 grands worth of EPs] I'ts a bit rough looking, needs a new paint job etc. The only thing I did wrong was not using stainless shafting on DEC.

The RA bearings are rated at 4 ton....very smooth.

[cristian abarca]

Hi XR8

I'm in the process of making a 10 inch mirror. I must say that I find it rather rewarding. If saving money is your reason for making a telescope then you are better off buying one, but if you are after the knowledge of how they work and the reward of knowing that you made it then build it. For my part I like the challenge of making things and I am finding it quite easy. Mind you I have had some setbacks but that is how things are. If you need help once you start drop me an email and I'll be glad to help. Once I finish this project I am going to start on my next one 20 inch monster. Be warned once you get the taste for building it can become addictive.

Regards Cristian

[Stargrazer]

I am a begginning amatuer and was thinking of buying the Saxon Dob-8", because I don't think I have the patience at this time to build one. Does anyone have any advice on whether this would be a good idea or not?

[cahullian]

Go for it mate the 8" Dob is a favoutite of mine.
He he he

Gazz

[Starkler]

I used to own one of these myself . Although not a bad scope, the GSO 8 inch dob is superior optically and cheaper. The Saxon dob i had had obvious spherical abberation on star testing whilst the GSO mirrors in the main have a much better figure.
On the plus side, the 8 inch f5 OTA and base are a really nice size to move and transport, while still capable of giving good views.