AlienFirstClass
professor emeritus
Reged: 02/13/09
Posts: 734
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I just brought home a Coulter RED tube 10" reflector.
The mirror is badly tarnished.
It has the typical "plumbing" nightmare for a focuser.
It came with the original binocular eyepiece.
Other than the tarnished mirror, the scope itself is in good condition.
Purchase cost = a $20 donation..the seller originally wanted to give it to me free.
The question I have is should I redo the mirror and upgrade the focuser, mirror mount and spider OR just sell it and use the proceeds for another 10" reflector?
If upgrading, what specific parts and vendors do you suggest?
Thanks for what suggestions you can offer.
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LivingNDixie
Lord of Ferrets
Reged: 04/23/03
Posts: 16248
Loc: Hoover, AL
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Yank the mirror out and have it refigured and recoated, dump the rest. It would make great ATM project.
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Preston
Celestron 11" Nexstar GPS XLT
Tak FS 78
Tak Teegul-Lapides
Lunt LS60T/Ha 60mm f/8.33
Vixen Porta Mount
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NewAstronomer
Post Laureate
Reged: 09/03/04
Posts: 3018
Loc: Scranton, PA U.S.A
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Quote:
Yank the mirror out and have it refigured and recoated, dump the rest. It would make great ATM project.
Agreed, you have the mirror, call OWL for estimate on test/refigure/recoat ...from their webpage looks like (without sale price!) $226 for basic refigure (unless its a Type II then its $441) + $104 for 92% coating. An imported 10" Dob from Orion is $499. With imported Dob you could get a good mirror, or a dud. Going with OWL you will get a very good mirror.
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Chris
279mm f/10 C11 SCT
250mm f/4.8 GSO Dob
70mm f/6 SV70ED
Atlas EQ-G + EQMOD
SVP Intelliscope & ST-4 Autoguide Mod
Vixen Portamount on the way!
DBK 21AU04
Olympus e-500 DSLR
Meade DSI-C
Edited by NewAstronomer (06/16/09 02:59 PM)
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lymorkiew45
professor emeritus
Reged: 12/30/07
Posts: 734
Loc: In the dark, and way out there...
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I would either keep it, have the mirror refigured, and recoated, and also upgrade the whole scope to a good level, although this work can exceed the cost of a whole nice brand new 10" telescope, so I would give that some thought. If the mirror needs a full refigure, that can run hundreds of dollars, not including the recoat, it's up to you...clear skies... 
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Jorgen
Starfinder 16 dob: Zambuto Optics! 
DS-10
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Z12
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http://cleardarksky.com/c/SanJoseCAkey.html?1
20 years in Southern Dragon Kung Fu, or dragon style embellished in magical arms.
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Lenardo
sage
Reged: 02/19/09
Posts: 221
Loc: Ma
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if the tube itself is in good shape,
i say rebuild...
new focuser, redone mirror(s), and new spider
i essentially redid my 8" celestron dob.. though the mirrors were fine. new focuser, redid the base some.
added laser pointer, adding dsc's...
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Dain
Carpal Tunnel
Reged: 03/24/05
Posts: 1596
Loc: N.Y. Adirondack Mnts. NGC 4565...
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I agree with the above to send the mirror to OWL. After that, I would decide if you want to put the effort into rebuilding the already bought scope or starting an ATM project. It depends on what you want into the scope, really. All around its a great deal for the $20 that you got it for. Good luck!
Clear Skies to All!
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Best,
Dain
Adirondack Mountains (my true dark sky site)
@ Cedar River Flow
Local Site
Clear Skies?
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JosephR
member
Reged: 11/30/05
Posts: 14
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I have upgraded my Coulter 10" over the years including focuser, mount, mirror cell, spider, OWL refiguring. It is wonderful; I have spent more than is probably justified, although I have an excellent performing scope now.
Joseph
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o1d_dude
o1der than dirt
Reged: 10/03/07
Posts: 2114
Loc: The TV/SV Wolfpack
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I'd take the advice given by the folks who responded to the original post.
You're only $20 into the scope so refiguring and recoating the mirror is a piece of cake...the mirror was basically free!
Upgrading the rest of the scope can be done over time. JosephR has appears to have done a masterful job with his. Use that as an inspiration.
You might also want to take a look at http://www.dobstuff.com for an alternative path to take.
I've been looking for a Coulter dob for some time now. Looks like you've struck gold while my poke is still empty. 
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Kit
'Don’t worry about what telescope you own, or its quality. Just get out under the night sky, and enjoy God’s wondrous universe.' - Thomas M Back
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AlienFirstClass
professor emeritus
Reged: 02/13/09
Posts: 734
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Quote:
Quote:
Yank the mirror out and have it refigured and recoated, dump the rest. It would make great ATM project.
Agreed, you have the mirror, call OWL for estimate on test/refigure/recoat ...from their webpage looks like (without sale price!) $226 for basic refigure (unless its a Type II then its $441) + $104 for 92% coating. An imported 10" Dob from Orion is $499. With imported Dob you could get a good mirror, or a dud. Going with OWL you will get a very good mirror.
Actually that is why I am asking for advice...the benefits seem to be marginal.
$226 (refigure) + $104 (recoating) is at least $330 (still using the old diagonal, focuser, spider, mirror mount and tube/base)
...versus $500 (new scope)
A difference of $170...or 33% more and you have a NEW scope.
To put a more positive spin on the problem, OWL currently has a 40% discount on their coatings...so in this case that means $40 less.
So now it is $210 or 42%.
Of course I am ignoring handling and shipping costs which would affect the final solution.
And I am assuming that the Coulter mirror will need refiguring because of their generally poor reputation.
So even after getting a scope for "free", one has to wonder if it is worth spending the money and effort to upgrade an old scope.
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Dain
Carpal Tunnel
Reged: 03/24/05
Posts: 1596
Loc: N.Y. Adirondack Mnts. NGC 4565...
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Quote:
So even after getting a scope for "free", one has to wonder if it is worth spending the money and effort to upgrade an old scope.
Whether or not you want to keep the scope is totally up to you. I would at least bring the mirror ( and scope if its too shabby looking ) up to par so you can at least sell it if you decide to get rid of it. I think thats the best thing you can do for a scope of $20.
Either way, you can't lose on this deal.
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Best,
Dain
Adirondack Mountains (my true dark sky site)
@ Cedar River Flow
Local Site
Clear Skies?
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cavefrog
sage
Reged: 11/11/08
Posts: 449
Loc: loozyanna
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yes, you could buy a new scope for $500, but after that it would not have a personality. it would also need upgrades to make it as you wanted it. that said I would think it breaks down to.... do you like working on your equipment? and by the time you got through rebuilding the coulter, you would have spent just as much, maybe more, but you would have a unique, PREMIUM scope.
also during the time of rebuilding you will be able to use it. spending money in smaller amounts at a time, instead of one large lump sum, and then spending smaller amounts anyway, for upgrades. is not the enjoyment of spending time on your scope worth something?
I like personalized stuff. it tells something about one.
I would go for the rebuild. and when I was done , show the person that you got it from , what he might have done.
Theo
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I am only an egg
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o1d_dude
o1der than dirt
Reged: 10/03/07
Posts: 2114
Loc: The TV/SV Wolfpack
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AFC, the "new" scope is not likely to have a mirror as good as one that's been refigured and recoated by OWL.
Just a thought.
And when has spending money ever stopped us?
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Kit
'Don’t worry about what telescope you own, or its quality. Just get out under the night sky, and enjoy God’s wondrous universe.' - Thomas M Back
Edited by o1d_dude (06/17/09 02:14 AM)
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AlienFirstClass
professor emeritus
Reged: 02/13/09
Posts: 734
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Quote:
AFC, the "new" scope is not likely to have a mirror as good as one that's been refigured and recoated by OWL.
Just a thought.
And when has spending money ever stopped us?
LOL...it has never stopped me before.
You are correct that that an OWL mirror would be a known quantity...but one should hope that a new scope would also have a good mirror.
Otherwise why does anyone buy a new scope?
This hobby really should have an ongoing quality testing program for optics in place so a buyer KNOWS what they are buying.
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Lenardo
sage
Reged: 02/19/09
Posts: 221
Loc: Ma
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how is the 2ndry mirror, that need recoating?
what I would do is, send mirror out for coat/figure, snag a quality focuser (seriously the GSO 2" crayford for a $104 is a great deal so is the 2" craford with the 10:1 dual focus for $139)
if you are Careful with cutting and setting up you won't have to do a thing with the spider (provided a vane is not in the way) cutting in a new focuser hole, just need a utility knife/saw and careful measurement- to keep the center of the existing hole, the center of the new hole.
when i altered my 1.25" focuser to the 2" crayford, i was off by about a 1/4" and had to adjust the vane/secondary position, but i had to do that anyway since the vane interfered with the new hole placement(vane was screwed into the old focuser)
also if you send the mirror out for recoating, have them Check to see if it Does need re-figuring, it may not. plus if it is refigured, you probably need to redo the vane anyway due to the altered (if it is altered) f ratio.
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csa/montana
Wild Spirit
Reged: 05/14/05
Posts: 40107
Loc: montana
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Joseph, that is one beautiful scope! 
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Carol
AstroTech 16" Dob (Thanks ASTRONOMICS!)
Vixen 80MF/AstroTech Voyager
Masuyama's 7.5, 15, 25W, 35mm,
Pentaxes; 5XW, 7XL, 10XW.
14mm Meade 4000 UWA
TV Panoptics; 22, 35
DreamCatcher Dobservatory, #2
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AlienFirstClass
professor emeritus
Reged: 02/13/09
Posts: 734
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Quote:
I have upgraded my Coulter 10" over the years including focuser, mount, mirror cell, spider, OWL refiguring. It is wonderful; I have spent more than is probably justified, although I have an excellent performing scope now.
Joseph
Nice looking scope Joseph...do you have closeups so one can see your modifications better?
Thanks
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Jim Romanski
scholastic sledgehammer
Reged: 01/02/05
Posts: 842
Loc: Guilford, Connecticut
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Have you taken it out for a look see? Tarnished or not you might be surprised. Some of the Coulters were pretty good.
If it were me I'd send it to OWL for recoating and testing. Based on both my visual test and what you get from OWL you can decide whether or not to refigure it.
And while I agree that you are better off rebuilding the scope I'd hang on to it and use it while you build a better mouse trap on the side.
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Jim
17.5" Dob "Project"
13.1" Coulter
8” Cave
NP 101 on a CG-5
25x100 binos
Naglers, Ethos, etc.
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AlienFirstClass
professor emeritus
Reged: 02/13/09
Posts: 734
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Quote:
Have you taken it out for a look see? Tarnished or not you might be surprised. Some of the Coulters were pretty good.
If it were me I'd send it to OWL for recoating and testing. Based on both my visual test and what you get from OWL you can decide whether or not to refigure it.
And while I agree that you are better off rebuilding the scope I'd hang on to it and use it while you build a better mouse trap on the side.
No I haven't had the time and the Cloud Gods are very angry at this time.
I do plan to test it before investing any money.
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o1d_dude
o1der than dirt
Reged: 10/03/07
Posts: 2114
Loc: The TV/SV Wolfpack
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AFC: If you decide you don't really want to fool with this scope, I will give you $20 for it.
Shoot, I'd even drive to pick up. Which coast do you live on?
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Kit
'Don’t worry about what telescope you own, or its quality. Just get out under the night sky, and enjoy God’s wondrous universe.' - Thomas M Back
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JosephR
member
Reged: 11/30/05
Posts: 14
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Here is a little closer shot.
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