View Full Version here: : Where to buy 24" + Mirrors in Australia?
Davekyn
21-12-2008, 08:32 PM
Hi,
Where does one buy large mirrors in Australia. The largest I can find is only 16".
tnott
21-12-2008, 08:57 PM
Try Mark Sutching. Otherwise its overseas I'm afraid.
http://users.tpg.com.au/masuch/dso/
SDM in Vic. orders ahead I think and may have one you can buy.
http://www.sdmtelescopes.com.au/prices.html
Paddy
21-12-2008, 09:03 PM
Looks like the old aperture fever has kicked in pretty quick and hard Dave!
Starkler
21-12-2008, 09:09 PM
You're in luck.
Custom made precision Newtonian telescope primary mirrors from 10" to 24" diameter
Davekyn
21-12-2008, 11:10 PM
Thanks guys,
I took apart my 12" gso and have pretty much got to know that scope inside and out. Not much to them really. As for SDM... No offense, but the prices seem way over the top. I am after APP not ultra specs. Mabey GSO will eventually come out with A 20" mirror.
I was checking out Orion just the other night in my don with a 19mm flat field & WOW!!!!!! The texture was amazing. I also found other other but smaller targets from my light pollouted yard but still gob smacked!
Yes, I am hooked on APP...what will $3000.00 get me in the way a mirror only? Bintel are selling the 16" light bridge for more than $3000.00!!! Seems a bit over the top as well. I figure I could spend that on primary mirror alone and now that I feel confident after pulling the GSO apart...I'll build my own "SDM...if you will...for LESS than the asking price. Sure it won't have the latest and greatest techy specs or quality & finish...but I'll still have a monster scope. Well that's the line of thinking this far.
Later...will ring Sydney Tommorow on mY break
Thanks again.
Dave:)
erick
21-12-2008, 11:53 PM
Great to see your enthusiasm, Dave. From what I have read, however, an element of caution? I don't think building a 24" truss reflector is a simple matter of scaling up what you have seen in a GSO 12" solid tube reflector. Apologies if I'm stating the bleedin' obvious, but I think there would be a lot of reading, designing and testing needed, as well as collecting the accumulated wisdom of the ATMers on the site here and elsewhere. Mirror cell design, flexure, altitude bearing size, balance, mirror cooling all come to mind as issues that are not simply scalable from a smaller scope? But again, this is what I have read rather than done! Best of luck and we look forward to seeing the result evolve.
Davekyn
22-12-2008, 06:35 AM
Absoloutly Eric...However as you obviously know, there is a wealth of I out there. Yes...I am aiming high to say the least. Perhaps a bad choice of words on my part..."not much to them"...I am no engineer, but like to do things methodicly & if I do take the plunge; I'll succeed one way or the other. Thanks for the reality check :) ... Perhaps the price of the mirror will be way over $3000.00 ... If over 4 Grand, I'll probably wait unroll prices drop.
GrahamL
22-12-2008, 08:33 AM
gso will sell direct .. there 16 "mirrors land here for less than 3 k
Good luck ,,building your own scope is a very rewarding experiance
though in dollar terms isn't always as cheap as you imagine
hand finished custom optics , all the top shelf running gear
comes at a price .. I guess there are savings to be had within but
you lose sight of the money part ( plenty of it) as you travel this journey
The end result is well worth the effort and something you can't put a price on.
cheers graham
tnott
22-12-2008, 10:08 AM
You could get a 16" GSO mirror or buy a secondhand 16" lightbridge that the owner has found too heavy to cart around and use the optics. Not necessarily going to be the same as premium optics though.
"The Dobsonian Telescope" By Kriege/Berry is essential reading before you even think about buiding a big one. There are newer designs around that are lighter and more compact, but this book has all the principles that you need to know first.:thumbsup:
Davekyn
22-12-2008, 12:47 PM
I am ordering books today...I believe that is the one I am looking at now. 100% agree about needing the books & will also rigourosly research the Internet.
The idea of picking up
A cheap 16" is a good one...however if I wanted to go that size, I would just shell out the 3+ grand at bintel. The main reason I am building is at this point, I am under the impression that a 24" inch can be built cheaper than "SDM" sells Them for, and aslo it will me some time before it's being sold as
standard.
I can get a new 16" GSO mirror for $999.00 therefore was hoping a 24" may be availabe for 3-4000. Will me ringing after lunch. I hate it when they talk premium to explain the 6-9000 price tag. The quality on the GSO optics look more than good enough to me. I just want a 24" version of it. No doubt ,I'll cop the premium jargon today when I ring Sydney. Ofcourse if I was a lot more wealthier, then yea...I would know the difference first hand...even then I may still wonder on the margin, in just the
Same way I would with a new release CPU.
Will keep you posted on the quote If your interested.
Dave
erick
22-12-2008, 12:57 PM
Dave
I think that the salesperson's expectation is that someone looking for a 20" mirror or greater is not interested in a "run-of-the-mill" result. They would be experienced observers who know and can appreciate the difference between "good enough" quality and "premium" quality. And see it as well!
However, I guess that would have been said about a 16" mirror some years ago? Now we have factory-produced, reasonable (?) quality at accessible prices.
Davekyn
22-12-2008, 01:31 PM
It all comes down to money Eric...I have been building computers since virtually they came to be & although I can apreciate the $$$$ands I have spent on the latest & greatest, I still question the margin VS $$$$$.
It's all a matter of time in that regard, be it much slower in this hobby. Bias can be income based...not to mention too much money & not enough heart ache learning. O oh ... Starting to dribble now...
I better read up some more. Is this the book some of you guys are revering too:
Http://www.willbell.com/TM/dobtel.htm
erick
22-12-2008, 01:55 PM
Yes, that is the book.
Also go to the Obsession Telescopes site and get a copy of their DVD sent to you. I recall that it shows "behind the scenes" at the factory, so you can appreciate what is behind some of these larger truss dobs.
Ian Robinson
22-12-2008, 02:15 PM
Dave ,
I'd wait til the exchange rate is going in the right direction and order one from somewhere like :
Newport Glassworks
Nova Optical
Swayze
Galaxy
You'd be looking at a lead time between 3 - 6 months once the order is placed I'd expect (unless they have one that fits the bill in stock - due to a cancelled order or maybe one made on spec).
Building the OTA and rocker box wouldn't be all that hard - the key components can all be had ready made , which only leaves the carpentry or metalwork (depending on how you want to do the scope).
Well , that's how I'd do a 24" if I decided to go for one , a lot can happen in the exchange rate in 3 to 6 months.
What surprizes me is that I've not heard of any chinese companies offering quality mirrors in the 16" --- 30" class yet. Maybe they are out there , anyone ? EDIT : found quite by accident Intane-Optics in china do parabolics to 33".
cristian abarca
22-12-2008, 02:23 PM
Can I suggest you make the 12 inch into a truss Dob first before you embark on a 20 inch. I built a 10 inch using Berry's book and it's not as easy as it sounds, but it is rewarding. Things always work out better the second time around.
Cristian
Davekyn
22-12-2008, 02:40 PM
Excellent idea...I understand what your getting at & agree I could gain some much needed skills.
Thank for the sugesting it. "Excellent idea!!"
PS...thanks Eric & Ian, will most certainly follow your advise as well. Glad I was able to talk about this with you all.
erick
22-12-2008, 02:42 PM
Dave, you might like to look at what Tim has done with a 10":-
http://www.iceinspace.com.au/forum/showthread.php?t=38956
This would be scalable to a 12". Perhaps not to 24" without mods?
Paddy
22-12-2008, 03:42 PM
One more suggestion from someone who has never made a telescope is that before you get too far in to deciding what your scope will be, it might be worth going to some of the bigger star parties and having a look at and through some big scopes. I found this very useful before my recent acquisition. I was tossing up between a 16" or 18" and to look through both size scopes showed me that there was not a great difference, but looking at them convinced me that the extra weight and bulk of an 18" was something that I wouldn't want. I reckon a 24" would be a big bit of kit to move around, although you would certainly collect a lot of light. I am no expert on optics, but I would also imagine that the bigger the mirror, the more critical good quality might be.
Starkler
22-12-2008, 04:29 PM
Something to bear in mind is that mass produced large mirrors greater than 12" in size have only been around for about a year or less.
You wont get a scaled up mass produced mirror from a chinese maker at chinese prices. Large mirrors are specialty items and come from small manufacturers in small volumes.
For a reality check the last price I heard on a new 16" mirror that wasn't a GSO was about $3k. Pyrex blank prices have gone up since then and our south pacific peso, down.
Satchmo
22-12-2008, 04:57 PM
Guess it was this same attitude to local industry that closed your local Newcastle steelworks ;)
Satchmo
22-12-2008, 05:28 PM
Dave, The current cost of importing a precision borosilicate fine annealed 24" mirror _blank_ and getting it aluminised ( without considering the cost of having it ground and polished ) is running at around AUD $6500. To import a 24"-25" finished mirror _to your front door_ from a reputable maker like OMI or Galaxy will currently set you back $15-$17,000 AUD.
If you can actually import a commercial anneal plate glass GSO 16" mirror currently to your front door for less than $1750 please let me know, I will buy one for my 13 yr old nephew :)
JethroB76
22-12-2008, 05:29 PM
Agree with Starkler, thats an odd typo
I would be surprised if you find a 24" mirror less than $8000
*edit seems I was being conservative haha, ok maybe $8000 four months ago
Ian Robinson
22-12-2008, 06:53 PM
No - it was poor management by the board of BHP and then by the same people who became the board of Onesteel.
And the Howard government did absolutely nothing to encourage Onesteel to keep the steelworks going (Newcastle's a labour seat) , nor did they do anything to help steelworkers retrain. Their silence at the time was deafening.
I can't comment on the quality of local mirror makers - never bought a mirror locally.
With the size of the Australian marketplace , the locals are never likely to have enough demand to compete with the big mirror makers overseas who have in the game for decades .
Starkler
22-12-2008, 07:04 PM
Ian when I went shopping for a mirror, the local producer won my business.
I asked price and availability for an OMI-Torus 15" f4.8 mirror, and they wouldnt make one for me, even thought its a catalogue item on their website. I could have got a 15" f4.5 for $3750 delivered but thats not what I wanted.
Seems they were too geared up into mass producing for Obsession telescopes and didn't want to reset a machine just for me.
I got the local product made to MY specifications and over $500 cheaper even after paying a surcharge for a custom focal length. The reputation of the mirror maker suggests it will be equal or better than the omi-torus.
Have you ever shopped for a mirror Ian?
Ian Robinson
22-12-2008, 07:49 PM
Yes I have, I bought several over the years , mostly for other people, and I've never had a problem getting one made to spec. I've dealt with mostly with Orion UK , Nova , NPGW and Parks.
The choice of wavefront tolerances , thicknesses, substrates and coatings is a big plus too.
Never bought one from Torus though I bought other stuff from them over the years on behalf of others.
Davekyn
22-12-2008, 08:06 PM
No problem...editing done...perhaps you can edit your response now as that's the only mention of it now.
Yes I understand & thought that the larger a mirror gets, the harder it would be to keep the quality. 0h well...I take it 16" inch must be it for now. That,a quite a price for the extra quality. Could you explain what the difference in quality is? Do they clean up better & can you clean them more often? Is there more brightness & contrast than what extra baffling can provide? Ofcourse I have no idea, however I would apreciate if someone could posibly explain the actuall difference between the two.
Don't get me wrong. I can apreciate those minor differences...however, if the difference is good enough, then surely someone could describe it?
Davekyn
22-12-2008, 08:14 PM
Wow!...ok I got the messege guys..."page just refreshed" if I can find that link on 999$ GSO mirror, I'll post it. Turns out I can't find it-go figure.
Mmmmmm...guess I,ok have to work on a 16" version then. May I ask can anyone comment on the extra 4" a 16" has over a 12". I really had no idea. My apollogies...I guess I just need to really mull over the "premium" aspect.
Paddy
22-12-2008, 10:03 PM
Well, I have to say that I have found the upgrade from 12" to 16" to be well worth while. Nearly double the light collected and better resolution. This is also going from a GSO 12" primary to a premium 16". I still reckon the best option is to have a look through and at a few. The other option for collecting more light would be a binocular telescope, but then you'd have to double your eyepiece collection. There would be quite a few people on this forum who could tell you more - I still haven't looked through a binewt myself yet.
Satchmo
22-12-2008, 10:20 PM
So basically you are happy to recommend a heap of US companies ( Nova, Swayze, Galaxy) you have never had dealings with over local production you have never had dealings with. Given the current US/AUD exchange rates , what can be said? : clearly treat advice from 'armchair experts' on forums with the caution it deserves.
Ian Robinson
22-12-2008, 10:55 PM
Well, I also recommended someone from the UK and
1) I never claimed to be an expert , umm I take you regard yourself as an expert ..
2) I've had dealings with these companies and they've done excellent work
3) market here in Australia small so every mirror above say 12" will be a one off therefore more expensive (economics), I've had no cause to deal with the local chap
4) I'm not twisting anyone's arm and forcing them to spend their money elsewhere (there is no compelling reason to buy locally except the exchange rate is currently unfavourable), but anyone looking to buy an optic will be well advised to talk to several suppliers before committing not just the locals.
:thumbsup:
monoxide
22-12-2008, 11:16 PM
i'd call Mark an expert, atleast regarding the topic of this thread.
anyway back on topic, i'd make a truss scope with what you have there to start with, i wouldnt want the first scope i built to be one you need a stepladder to look through :P
i'm still in the planning stages of converting my 12" dob to a truss dob.
theres a lot of people on here that have done it all before and can offer excellent advice. also if you start small you can see where the problem areas might be when you go bigger.
Davekyn
22-12-2008, 11:22 PM
Sounds like good advice Rob. Now that I am much more informed on the situation, I do believe I will settle for buying the recomended book & even the DVD Erick mentioned. From there I will experiment with my current Dob. The Bino dob setup actually makes sense now...I use to wonder why people bothered, but clearly that too could be an alternative with chineese optics.
Whatever the score...thankyou very much.
JethroB76
23-12-2008, 12:27 AM
That 'local chap' eh?:lol:
Starkler
23-12-2008, 02:17 AM
Done, and thanks.
Satchmo
23-12-2008, 09:44 AM
You've clearly done absolutely _zero_ research on that one...
:rolleyes:
Ian Robinson
23-12-2008, 10:29 AM
Since you reckon I am wrong. So how big do you think it is - volumewize ?
Satchmo
23-12-2008, 11:16 AM
The Universe ? :)
bmitchell82
23-12-2008, 12:12 PM
Satchmo, stop playing with Ian :D and by the way can you look at my post in ATM DIY about multi mirror optics and comment.?
skies2clear
23-12-2008, 04:15 PM
Oh dear, if only the truth was apparent! :)
Funny and sad!
tnott
23-12-2008, 05:25 PM
Davkyn,
The only reason the GSO mirrors are substantially cheaper is that they are mass produced in China. No such thing exists for mirrors above this size. They are all custom made products - which is probably just as well as the difficulty in making them goes up almost exponentiallythe bigger they get.
Some GSO optics turn out pretty OK and others are mediocre to lousy. The risk you take when you buy the cheaper stuff is that you may have to get it refigured anyway.
I think the amount the good US and Aussie mirror makers charge is a bargain, given the amount of work involved in making them. You should see how much my plumber charges per hour.:rofl:
Ian Robinson
23-12-2008, 08:18 PM
:whistle: so you've researched the market in Oz extensively then.
Paddy
23-12-2008, 09:05 PM
Still relevant it seems.
JethroB76
23-12-2008, 10:13 PM
:lol:
AstroJunk
24-12-2008, 12:52 AM
Just a few years ago, an 8” scope was as big as one could afford. All of a sudden, a 16” monster can be had for less than 3 grand. How amazing is that?! The difference between mass produced and hand made is reducing dramatically, and it would be lovely if one day even bigger mirrors were available on the cheap.
But right now, I doubt it – I am lucky enough to own a superb 20”, and more so, in a position to use it on every cloud free night. Most of my Astro-mates however are more than content with much smaller scopes for astrophotography and the like. Also, beyond 16”, these scopes become a real handful. It’s not that one person can’t handle a big dob, it’s just that most are unwilling to. Especially if they have to travel with the beast every time they want to use it. I doubt if there will ever be a mass market for big dobs, so get used to the prices as there is no such thing as an OK large mirror – all are premium grade.
Don’t be put off though, if you have Aperture Fever, then only a big dob will do. Start saving up for a grade A mirror set (and yes, it’s going to cost you ten grand or more) and get building your Dob. You will soon find that the difference in price between a custom made SDM and your own build will be much smaller than you expect, so unless to are very handy at woodwork, think again.
Which ever way you chose, BIG IS BETTER.
Biased as ever,
Jonathan.
Garyh
24-12-2008, 07:40 AM
:doh::rolleyes:
Oh dear!
How about this guy, he knows what he is talking about!
http://users.tpg.com.au/masuch/dso/
Really I don`t think you can compare a mass produced 16" mirror to a hand figured premium mirror and would be worth every cent extra. I would incline to get a smaller premium mirror if your budget doesn`t stretch far enough.
my few cents worth anyway.
cheers Gary
Davekyn
31-12-2008, 09:31 AM
Hi again guys,
I understand on the premium debate now...well it's no debate really. Good post Johno...thanks man, i got a lot out of that.
I know the follwing site may not be premium enough for some here...BUT...I was stoked to find antoher place the sells larger than 16" and thought I would ask what some of you thing about this place...like I know they are great to deal with in the phone and all...what do you think about the large mirrors for a bugdet large app to apease the notion?
17.7" $2270.00AUD Larger sizes available...
http://www.telescopes-astronomy.com.au/telescopes036.htm
This was the place I found ages ago...but could not find the link...anyways I hope this link will help others also find thier budget on the lower end for now......Let me know what you think?
Dave
Omaroo
31-12-2008, 12:11 PM
:rolleyes: I'd say he has.... yup, I'd say he has. He's the one bloke here who's in the business, so to speak.
Do your research before you want to argue with someone here. It helps.
theodog
31-12-2008, 12:33 PM
Have owned a few "local bloke" mirrors myself.
Time was a letter of quality from the "local bloke" was something to have for your mirror. I believe it is still so.:)
All being well it will be a "local bloke" mirror for Project 24. Not yet though.:D
AstroJunk
31-12-2008, 01:33 PM
This thread is getting a bit mean spirited:poke:
Omaroo
31-12-2008, 01:43 PM
Sorry - just tired of inaccurate "guesswork" statements that are written to appear as gospel from someone who keeps rattlling off ill advice off the top of their head.
AstroJunk
31-12-2008, 02:44 PM
Maybe it would be easier to compare if "the local guy" put some prices on his website like the other mirrror makers do. Then we could be all be know it all's together.
Nah, what was I thinking, its much easier to just take the piss.
Davekyn
31-12-2008, 11:20 PM
Is this the way people carry on at star parties? I guess this thread has been highjacked. Pretty encouraging lot?
AstroJunk
31-12-2008, 11:44 PM
Yes.
If you want the thread back, then ring the only known (to me) maker of large mirrors in Australia. He is called Mark Suchting, and his work is of the highest quality. If you can't find his number then PM Satchmo, 'cos he is the same person.
Ian Robinson
31-12-2008, 11:49 PM
Good points Astrojunk ....
.... that reminded me why I stopped being in astroclubs and going to starparties all those many many years ago.
Davekyn
01-01-2009, 06:27 AM
Um.......Happy New Year everyone...Thankfully I have met some people, really worth knowing on this site;)
Later all...Have to work today:(
Dave
iceman
01-01-2009, 08:04 AM
This thread has reached its end.
vBulletin® v3.8.7, Copyright ©2000-2024, vBulletin Solutions, Inc.