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Equipment Discussions >> ATM, Optics and DIY Forum

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StarryHost
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Reged: 01/13/09

Loc: Vista, CA
Re: Why no CHiefs intrest??? new [Re: Mike I. Jones]
      #5600998 - 01/02/13 10:47 AM

Yes,
He has given a ton to this project in time and expertise as have others. I love the giving nature of the folks in this group.

Jack


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kfrederick
Carpal Tunnel
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Reged: 02/01/08

Re: Why no CHiefs intrest??? new [Re: StarryHost]
      #5601108 - 01/02/13 11:40 AM

This 17 needs a good mount so I can take CCD pic .Think A GEM? . The paper Dave did for Jack 10 inch is great . This design uses off the shelf lens and a flat secondary . Daves and Mike work is great about explaining how to make one .Like I said in the top his work cannot be understated . As well as Mike and ED . I am sure as more people build these can will only get better . Thanks for the kind words .

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Jeff Morgan
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Reged: 09/28/03

Loc: Prescott, AZ
Re: Why no CHiefs intrest??? new [Re: mark cowan]
      #5601480 - 01/02/13 03:55 PM

Quote:


As a mirror maker, there's mostly one surface (the primary) that I'd make any profit on.




OK Mark, here is an idea that seems largely forgotten: The Sasian unobstructed Newtonian as published in Sky & Telescope March 1991?

For those not familiar, it used a tilted 6" f/9 paraboloid. The secondary mirror was ground with a torodial surface and mounted to pass light back across the tube to the focuser. Like the Chief it is unobstructed, but does not result in much (if any) length reduction compared to a standard Newtonian. It generally resembles the DGM off-axis Newtonian, but without the waste inherent in creating the daughter mirrors.

That would give you two pieces of glass fabricate and sell (one of them being very unique), and a layout that would be generally familiar to most users. I would imagine support efforts would be quite reasonable.


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Jim Romanski
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Reged: 01/02/05

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Re: Why no CHiefs intrest??? new [Re: kfrederick]
      #5601501 - 01/02/13 04:05 PM

I've been following these Chief threads with great interest. My Dad gave me an old but essentially unused 12.5" F/8 Upco mirror which is 40+ years old. It's in spectacular condition and probably doesn't even need to be coated. He thinks it has a very good figure too. It would be a great candidate for making a Chief since it has 100" focal length and would otherwise make for a very long standard newt.

My problem is time. I'm still finishing the 17.5" dob that my father-in-law started. Then I have an 8" Cave to do some resoration on. Oh and I really want to rebuild the 13.1" Coulter. So the Chief is last in line and I don't know when I'll get started on it.

I would like to know if I can get off the shelf lenses for the project. I might even go ahead and get them now and layout the design. But it'll be sometime before I actually start building it.


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Ed Jones
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Reged: 04/06/04

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Re: Why no CHiefs intrest??? new [Re: Jim Romanski]
      #5601976 - 01/02/13 09:15 PM

Jim,
Yes it may be possible to make a 12.5 inch F/8 Chief. Ross Optical has a 3 inch diameter negative lens of the right focal length. It can be matched up with a 60 mm convex lens (no one makes a matching 3 inch convex lens). I've never tested any Ross Optical lenses so I don't what quality they make but in theory it works.


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mark cowan
Vendor (Veritas Optics)
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Reged: 06/03/05

Loc: salem, OR
Re: Why no CHiefs intrest??? new [Re: Jeff Morgan]
      #5602191 - 01/02/13 11:50 PM

Quote:

For those not familiar, it used a tilted 6" f/9 paraboloid.




Just a bit small. An awful lot of unobstructed designs don't scale up well, and really (just my opinion) the interesting ones are the ones that do - SP, CHief, Schupmann, and maybe one other that I can't recall offhand...

Best,
Mark


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sqrlman
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Reged: 01/02/08

Re: Why no CHiefs intrest??? new [Re: Jeff Morgan]
      #5602448 - 01/03/13 07:24 AM

The Sasian unobstructed Newtonian actually used a F12 primary.
I have the original telescope shown here:
http://bhs.broo.k12.wv.us/homepage/alumni/dstevick/unobnewt.htm
The optics need to be remounted in something less flimsy. If anyone is interested in it send me a PM.

Steve


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kfrederick
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Reged: 02/01/08

Re: Why no CHiefs intrest??? new [Re: sqrlman]
      #5602540 - 01/03/13 08:46 AM

Steve feel free to talk about the telescope as any others .

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tim53
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Loc: Highland Park, CA
Re: Why no CHiefs intrest??? new [Re: sqrlman]
      #5602751 - 01/03/13 11:08 AM

Quote:

The Sasian unobstructed Newtonian actually used a F12 primary.
I have the original telescope shown here:
http://bhs.broo.k12.wv.us/homepage/alumni/dstevick/unobnewt.htm
The optics need to be remounted in something less flimsy. If anyone is interested in it send me a PM.

Steve




I remember that scope and article. That would be splendid on a Springfield mounting.

-Tim.


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kfrederick
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Reged: 02/01/08

Re: Why no CHiefs intrest??? new [Re: tim53]
      #5604605 - 01/04/13 11:33 AM

This will work best is in large sizes the bigger telescope has more HP The improvement can only happen if everything is 100% . Why bother to make one 90% . Go with the hyperbolic primary/ curved secondary and the APO lens then the CHief could be a HDT High Def Telescope . By far the most important part is the primary and having Carl do that was a good move . This can only get better.. Mikes numbers are great . So glad he is here on cloudy nights .

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ed_turco
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Reged: 08/29/09

Loc: Lincoln, RI
Re: Why no CHiefs intrest??? new [Re: kfrederick]
      #5604672 - 01/04/13 12:17 PM

Seems like everyone forgot that Jose Sasian also created a Yolo-like setup with two concave mirrors. He even provided a computer program to assess just about any system. As I remember a 6" Sasian system f/10 I assessed and found this to be as good as a 6" f/10 Newt. And, this system scaled up nicely.

But none of youse guys, (just kidding) would know what to do with an executable DOS program, would you?

By the way, Jose Sasian has a PhD after his name for precisely his work in creating these systems. Quite the man; he kindly talked to me on numerous occasions, though I never built this system.


ed_turco


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MKV
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Reged: 01/20/11

Re: Why no CHiefs intrest??? new [Re: ed_turco]
      #5604687 - 01/04/13 12:27 PM

Ed, I wrote my own raytrace and optical analysis program in the 1981 on Sharp PC1500 in BASIC and compiled it with on an IBM AT. I also programmed my Epson dot matrix printer for my own proportional width fonts and scientific symbols in BASIC, along with full justification and proportional spacing printing commands. Almost everything people do with spreadsheets today I did with BASIC for many subroutines.Some of us still know what to do with an executable BASIC file.

Mladen


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kfrederick
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Reged: 02/01/08

Re: Why no CHiefs intrest??? new [Re: ed_turco]
      #5604697 - 01/04/13 12:33 PM

Ed if you have the program feel free to post it .Or any other designs .They are all cool and worth optimizing . Tall order topping a great newt . But a newt has been optimized . Mike was talking about a Hamintonian yolo . A warped Hchericalian with a CCD would be great one surface . And the ccd could go any place . They have one CCD camera that downloads a 8.5 meg pic every second . No eyepiece needed . or ladder or be in the cold .

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tim53
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Loc: Highland Park, CA
Re: Why no CHiefs intrest??? new [Re: kfrederick]
      #5604752 - 01/04/13 01:03 PM

Putting a ccd camera at the prime focus of a Newt primary is something I've been wanting to do for a long time. This will work for larger apertures better than smaller ones because the camera doesn't scale up with the aperture, so the CO - if you use a parabolic primary - gets relatively smaller as the aperture increases. The practical upper size limit of such a "camera" system might only be limited by the length of cabling you need to plug the camera in. No more ladders! And if you put another camera at the focus of a finder and a guidescope, no more eyepieces!

I like the machine vision cameras because many of them are very small (Pt Grey fleas are about 1 1/4" cubes. Depending on the camera, you could get up to about 6 megapixel mono or RGB 16-bit digital video at 15fps or so, up to 60 minutes/frame. Only thing they lack is cooling, but you wouldn't need to cool a planetary monitoring camera (like watching for impacts on Jupiter).

-Tim.


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Startraffic
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Reged: 02/12/06

Loc: Lat. 39.143345, Long. -77.1748...
Re: Why no CHiefs intrest??? new [Re: kfrederick]
      #5604794 - 01/04/13 01:24 PM

kfrederick,
I wouldn't say no interest. I have plans under development for a 14.5" f30 Schiefspiegler binoscope on a 16ft trailer observatory. A kissin' cousin of a CHief I believe. The math does hurt my head & I haven't even finished the mirror designs yet. I have the trailer though.

Clear Dark Skies
Startraffic
39.138274 -77.168898

Edited by Startraffic (01/04/13 01:45 PM)


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audioaficionado
scholastic sledgehammer


Reged: 05/24/12

Loc: Medford, Orygun, USA
Re: Why no CHiefs intrest??? new [Re: Startraffic]
      #6036677 - 08/20/13 02:45 PM

Very fascinating ATM you've built Kevin. I'm interested in the concept, but I don't think I could do an ATM anytime soon. This doesn't look like a good first project since I don't have access to a decent workshop. I don't think my 10x12 garden shed would cut it lol.

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Pinbout
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Reged: 02/22/10

Loc: nj
Re: Why no CHiefs intrest??? new [Re: audioaficionado]
      #6036705 - 08/20/13 03:03 PM

that is really no excuse.

I have no shed, I have nothing but metal frame with rotting birch ply that's been outside for 3years, time to replace finally

check it out in this vid. I've built 5-6 scope on it, ok I have another foldable table that helps out while painting...

http://www.youtube.com/watch?v=i43O2BGj0-s


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