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Looking for 30" mirror maker

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#1 Dick Jacobson

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Posted 06 July 2014 - 01:07 PM

I am planning to build a 30" Newtonian and have been putting together a list of possible suppliers in North America for the primary mirror. So far my list consists of Cary Chleborad (Optic Wave Laboratories), Mark Cowan (Veritas), Normand Fullum, Steve Kennedy, Mike Lockwood, James Mulherin (OMI/Torus), and Terry Ostahowski. Is there anyone else I should contact (besides a psychiatrist)?

And no, I really don't care how tall the mirror maker is.

#2 herrointment

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Posted 06 July 2014 - 01:27 PM

You're taking all the fun outa this, you know.

Can't help you, but I hope you bring the scope over to N. Wisconsin for free looks sometime before I die.

#3 kfrederick

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Posted 06 July 2014 - 02:05 PM

Might wont to ask Carl Zambuto his coater I think will do 30 inch would not cost to ask him Do you have the glass ? How fast you wont to go ? And how thick? If f3 and faster I say Lockwood

#4 mark cowan

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Posted 06 July 2014 - 03:21 PM

Hi Dick,

I don't have 30" capacity, and won't for maybe a year. But thanks for thinking along those lines.

Best,
Mark

#5 Dick Jacobson

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Posted 06 July 2014 - 04:17 PM

Can't help you, but I hope you bring the scope over to N. Wisconsin for free looks sometime before I die.

I usually go to Northwoods Starfest and hope to get there with my 30" before I die.

#6 Dick Jacobson

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Posted 06 July 2014 - 04:21 PM

Might wont to ask Carl Zambuto his coater I think will do 30 inch would not cost to ask him Do you have the glass ? How fast you wont to go ? And how thick? If f3 and faster I say Lockwood

Zambuto advertises only up to 25" but I agree it wouldn't hurt to ask. I'm planning f/4.5.

#7 kfrederick

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Posted 06 July 2014 - 04:53 PM

If you do not mind me asking why a f4.5 ? at f3.5 be 30 inches shorter .

#8 Dick Jacobson

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Posted 06 July 2014 - 06:30 PM

If you do not mind me asking why a f4.5 ? at f3.5 be 30 inches shorter .

Several reasons. My 14" and 20" scopes are f/4.5 which I consider the maximum acceptable speed without a coma corrector. For the 20", I invented a periscope that brings the eyepiece down to feet-on-the-ground level and I also plan to build one for the 30". I also invented an improved astronomy ladder for higher eyepiece positions. I have some structural ideas that I'd like to try out on a tall 30" scope. The optical quality is likely to be better at longer focal lengths (though I've read very good things about Mike Lockwood's fast mirrors). The cost generally goes up for faster mirrors, and a slower mirror is likely to attract more bidders.

#9 kfrederick

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Posted 06 July 2014 - 06:35 PM

My best views were in a 32 f3.6 Changed my mind seeing those images it was on the Keys so that was some of it .

#10 Mike Lockwood

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Posted 06 July 2014 - 10:02 PM

Several reasons. My 14" and 20" scopes are f/4.5 which I consider the maximum acceptable speed without a coma corrector. For the 20", I invented a periscope that brings the eyepiece down to feet-on-the-ground level and I also plan to build one for the 30". I also invented an improved astronomy ladder for higher eyepiece positions. I have some structural ideas that I'd like to try out on a tall 30" scope. The optical quality is likely to be better at longer focal lengths (though I've read very good things about Mike Lockwood's fast mirrors). The cost generally goes up for faster mirrors, and a slower mirror is likely to attract more bidders.

I would still use a Paracorr at f/4.5. It greatly increases the useable field size, and does not degrade the image.

Faster focal ratios will perform similarly if appropriate eyepieces are used.

Yes, a faster mirror will cost more, but consider the image degradation cause by a periscope.

Email me if you have questions.

#11 Stephen Kennedy

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Posted 06 July 2014 - 10:44 PM

If you are talking about Optic Wave Laboratories near Sacramento, Ca, I am wondering if they are still in business. My Mikage 210 mm F/7 had some sort of corrosive chemical spilled on it during shipment from Japan which stained the primary mirror. Since I am just south of Sacramento I looked for a local company that could recoat the aluminum on my telescope and found the OWL website back in January.

They had a notice saying that they were temporarily not accepting any new work due to malfunctioning equipment and they would be up and running again after the Spring Equinox. I called them in April and they said that they had still not been able to repair their coating chamber. I called them several more times over the next month and was repeatedly told they were still plagued by equipment malfunctions.

Ominously, I have called them several times again over the past month and no one answered the phone. I had heard good things about OWL and they were only a short drive away but it is looking like I am going to have to find some place else to recoat my mirror.

Although my name is Steve Kennedy and I am currently in the polishing phase of an 8 inch F/7 mirror I just ground, I am not that Steve Kennedy who is known for making very large and very fast mirrors and unfortunately can not make a 30 inch F 4.5 mirror. In fact, I am beginning to wonder if I can make an 8 inch F7 mirror.

#12 kfrederick

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Posted 07 July 2014 - 06:19 AM

Might wont to look for a coulter 29 f4.5 and get it re worked

#13 Dick Jacobson

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Posted 07 July 2014 - 09:40 AM

Yes, a faster mirror will cost more, but consider the image degradation cause by a periscope.

I don't see any significant image degradation in my periscope. The upper lens is a prime (non-zoom) telephoto with the light going through "backwards". This lens needs to be at least as fast as the mirror to avoid light loss. F/4 telephotos are available at reasonable cost while faster ones tend to be extremely expensive, so the telescope mirror shouldn't be faster than f/4 to be compatible with a periscope (at least my design). If anyone knows of faster high-quality lenses that are available at a reasonable price, I'd like to hear about it!

#14 kfrederick

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Posted 07 July 2014 - 11:36 AM

A 30 inch f3 would be 6 ft from the mirror to eyepiece and maybe 5.5 ft at f 2.8 . Might not be easy to mirror to make as a 4.5 but with the coma corrector should work fine

#15 Chuck Hards

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Posted 07 July 2014 - 01:44 PM

Were I doing this, I'd seriously consider a low-rider configuration for a 30".

#16 Pinbout

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Posted 07 July 2014 - 02:19 PM

I'd seriously consider a low-rider


if you had a low rider, why can't we be friends, while we're slippin into darkness ...

:foreheadslap:

tried to use spill the wine but the present tense doesn't really work.

#17 davidpitre

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Posted 07 July 2014 - 05:46 PM

I would seriously do some web research (including Cloudy Nights) on peoples' experiences with OWL before choosing him. You might also check his Better Business Bureau rating.
I am certain Carl Zambuto is not doing 30" mirrors.

#18 polaraligned

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Posted 07 July 2014 - 06:58 PM

I am planning to build a 30" Newtonian and have been putting together a list of possible suppliers in North America for the primary mirror. So far my list consists of Cary Chleborad (Optic Wave Laboratories), Mark Cowan (Veritas), Normand Fullum, Steve Kennedy, Mike Lockwood, James Mulherin (OMI/Torus), and Terry Ostahowski. Is there anyone else I should contact (besides a psychiatrist)?

And no, I really don't care how tall the mirror maker is.


Mike Lockwood is a no brainer here....He is straight up, honest, never has put a bad mirror out there and does exceptional quality work. He has done 50" mirrors and more complex optics such as RC's. I have a 28.5" that is not yet in service but I use a 14.5" that Mike did for me and it is perfect.

- Oh, and Sky and Telescope published incredible images from a Dream Astrograph 4 months in a row earlier this year. Mike made those mirrors. Mike also made the primary mirrors (hyperbolic shape) for the Centurian 28 Astrographs.

#19 kfrederick

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Posted 07 July 2014 - 07:24 PM

I would seriously do some web research (including Cloudy Nights) on peoples' experiences with OWL before choosing him. You might also check his Better Business Bureau rating.
I am certain Carl Zambuto is not doing 30" mirrors.

I was talking to Carl and he said he would not make a bigger mirror than he could coat I think he can coat a 30 would not be bad to ask him .

#20 Pinbout

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Posted 08 July 2014 - 05:44 PM

I would seriously do some web research (including Cloudy Nights) on peoples' experiences with OWL before choosing him. You might also check his Better Business Bureau rating.
I am certain Carl Zambuto is not doing 30" mirrors.

I was talking to Carl and he said he would not make a bigger mirror than he could coat I think he can coat a 30 would not be bad to ask him .


Did you find out if he's a "walking dead" fan. You know the tv show on amc.

#21 kfrederick

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Posted 08 July 2014 - 07:08 PM

Not sure what you are asking .But he is a very cool guy

#22 Pinbout

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Posted 08 July 2014 - 07:13 PM

(SPOILERS) Cast Speculates on What's Next: The Wa…: http://youtu.be/iOuRpCMwONo

#23 Stephen Kennedy

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Posted 08 July 2014 - 10:46 PM

The last time I was able to reach anybody at OWL by phone, I think it was Cary, he described his unsuccessful attempts to repair their coating chamber. It also sounded like there were other equipment problems.

The impression I got was that, instead of calling in experts on these devices, they were trying to make the repairs themselves but did not really know how to fix the machinery. I could not understand why opticians were trying to repair mechanical and electronic devices themselves.

#24 gatorengineer

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Posted 09 July 2014 - 02:54 PM

Dick,

The difference between a 20 f4.5 and a 30 f4.5 is enormous. Find someone with a 25 F5 obsession take it for a test drive and imagine another step. i have owned 20 f4.5s and 20f5s, they were a world different than a 25 f5, a 30 f4.5 is a two person scope with a serious orchard ladder.

with the 3 inch paracorr, I would have no issue going 3.5 or faster.... Kevins finished the first one and we star test in a week, so if you are in the area, swing by and test a 36 3.5....

#25 mark cowan

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Posted 09 July 2014 - 09:27 PM

Kevins finished the first one and we star test in a week


Good, 'cause I was just going to suggest that. :waytogo:

Best,
Mark






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