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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: First Light: 10" F11 Report new [Re: David Castillo]
      #5563106 - 12/09/12 08:40 PM

The last Sherpa I used would not work without a parachute. Now I use oompa looompas.

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StarryHost
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Reged: 01/13/09

Loc: Vista, CA
Re: First Light: 10" F11 Report new [Re: David Castillo]
      #5563111 - 12/09/12 08:45 PM

Several of you have mentioned your long focus news which sound like real gems... With the success of this project maybe I need to start a conversion business! There must be dozens and dozens of dollars in a business like that!
;-)


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Jeff Morgan
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Reged: 09/28/03

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Re: First Light: 10" F11 Report new [Re: StarryHost]
      #5564064 - 12/10/12 12:19 PM Attachment (22 downloads)

Quote:


I've not purchased it yet but I'm leaning towards this solution because I still have to get that dang ladder into the car.




The standard car interior is a pretty limiting factor for large gear. Years ago I used a kayak roof rack for my old 10" f/9 scope. No reason you could not put a ladder up there.

Currently I already have a kayak micro-trailer, so it is a natural to press it into service for hauling astronomy items. During kayak season it takes about 10 minutes to add/remove fittings to switch uses for the trailer. It really opens up the possibilities for astro equipment, and in my case was a bit more practical than buying a pick-up truck.


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tim53
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Reged: 12/17/04

Loc: Highland Park, CA
Re: First Light: 10" F11 Report new [Re: Jeff Morgan]
      #5564119 - 12/10/12 12:57 PM

My dad conditioned me to prefer vans over cars when he traded our 1953 Hudson Hornet in on a 1960 Ford Econoline. I drove that and his 1966 dodge van until buying my first VW van in 1975. I've had vans in the corral ever since.

It's nice to easily accommodate scopes 8 ft long as a rule!

Tim


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kfrederick
Carpal Tunnel
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Reged: 02/01/08

Re: First Light: 10" F11 Report new [Re: tim53]
      #5564133 - 12/10/12 01:00 PM

Jack how high was the eyepiece when you used this mirror as a chief?

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StarryHost
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Reged: 01/13/09

Loc: Vista, CA
Re: First Light: 10" F11 Report new [Re: kfrederick]
      #5564252 - 12/10/12 02:03 PM

Kevin,
of course with the Chiefspiegler the ep is half the height. Over the last two weeks I made more progress on the chief but still have some variables not controlled. . I have made this newt box such that I can continue on the chief project. Thank you for your help and encouragement. You are a blessing.


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glennnnnnn
sage


Reged: 10/20/09

Loc: San Diego, CA
Re: First Light: 10" F11 Report new [Re: StarryHost]
      #5564445 - 12/10/12 04:23 PM

Tim53
I thought I saw a blue pick-up type 2 in one of your posts!
I have a beautiful refurbished/functionally restored 1970 1600 van. Love it and can haul at least a 10 foot telescope in comfort inside. And off-road it goes almost anywhere (like in the Anza-Borrego desert.)
However I think that Jack needs an old fire engine with the ladder. That should accomodate his massive f/11 !
That would make it a UFO: Unidentified Focusing Object.


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StarryHost
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Reged: 01/13/09

Loc: Vista, CA
Re: First Light: 10" F11 Report new [Re: StarryHost]
      #5564515 - 12/10/12 05:02 PM

My ota does break down into sections. It only takes a couple of minutes to set up! :-)

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kfrederick
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Re: First Light: 10" F11 Report new [Re: StarryHost]
      #5564523 - 12/10/12 05:06 PM Attachment (24 downloads)

I think it is 33 inches from the primary to focus if you use this mirror as a CHief

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glennnnnnn
sage


Reged: 10/20/09

Loc: San Diego, CA
Re: First Light: 10" F11 Report new [Re: kfrederick]
      #5564599 - 12/10/12 05:51 PM

Looks complicated! How do you ever place L1 & L2 at those angles? Trig the linear dimensions?

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StarryHost
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Loc: Vista, CA
Re: First Light: 10" F11 Report new [Re: StarryHost]
      #5564662 - 12/10/12 06:19 PM

Glen,
The chief must be very carefully laid out. I have ever document describing what we did by Mike, Dave, Peter and Kevin. Then keen had a waterjet guycut the prescribed ages. My problem is that the material we choose allow too much movement so I am having to lock of each variable one at a time. Very time consuming and difficult, but the result should be worth it.


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StarryHost
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Reged: 01/13/09

Loc: Vista, CA
Re: First Light: 10" F11 Report new [Re: StarryHost]
      #5564685 - 12/10/12 06:35 PM

You will laugh... I did that last post while stuck on the pirates ride at Disneyland! We finally gotninstuck and the ride is now closed. Adventure!

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tim53
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Reged: 12/17/04

Loc: Highland Park, CA
Re: First Light: 10" F11 Report new [Re: glennnnnnn]
      #5564714 - 12/10/12 06:56 PM

Quote:

Tim53
I thought I saw a blue pick-up type 2 in one of your posts!




Close! It's tan (though it was originally Sealing Wax Red) and rust!

Quote:

I have a beautiful refurbished/functionally restored 1970 1600 van. Love it and can haul at least a 10 foot telescope in comfort inside. And off-road it goes almost anywhere (like in the Anza-Borrego desert.)




Oddly, I've never owned a "breadloaf" before. Several "Splitties", one "Brick" (1980 Westfalia), and two Eurovans. The Eurovan MV weekender is a great scope hauler, though the 60 singlecab is the one to carry the Cave 12.5" with.

Quote:

However I think that Jack needs an old fire engine with the ladder. That should accomodate his massive f/11 !
That would make it a UFO: Unidentified Focusing Object.




How 'bout one of these?:


All seriousess aside, though, some of the rolling platforms available are really neat. I think Stonyridge observatory uses one of those scissor lifts for accessing the eyepiece of their 30" f/5 Newtonian. I was invited up there for a night of observations sometime in the mid to late 80s.

-Tim.


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Ed D
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Reged: 04/30/10

Loc: Sunny South Florida
Re: First Light: 10" F11 Report new [Re: David Castillo]
      #5564863 - 12/10/12 08:40 PM

WOOOW!!! Your scope kind of reminds me of the rocket ships in the B&W movies from the 1950s and early 1960s.

Ed D


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Mike I. Jones
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Reged: 07/02/06

Loc: Fort Worth TX
Re: First Light: 10" F11 Report new [Re: Ed D]
      #5564930 - 12/10/12 09:24 PM

Jack - check out my new thread on a 71.5mm eyepiece for you. Oh man, that would be an awesome sight through your 10" f/11!
Mike


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glennnnnnn
sage


Reged: 10/20/09

Loc: San Diego, CA
Re: First Light: 10" F11 Report new [Re: Mike I. Jones]
      #5565074 - 12/10/12 11:06 PM

tim53-
Yes! That would work and I should have thought a little more about it.
I spent almost 4 years in (then) West Germany the land of gizmos and garage engineers. Although there were just as many zany contraptions as those elegantly designed by dedicated engineers, I'm certain that somewhere in that range of inventors there would be someone who had addressed the very problem of the exceedingly long telescope that would probably have something to do with a VW.
A real problem though. Through the ages it seems like one of the biggest challeges to large telescopes is getting your eyeball where you can see.
Imagine a telescope so large that you could ride inside at the focal point! Imagine something like that parked in a safe orbit with gyros to point anywhere and being able to see forever!!!!
Now a camera (Hubble, etc.) is probably better with the potential for light amplification and selective spectral viewing, but I don't think there's any substitute for direct viewing with your very own eye.
Mostly because I like it so much.
A breadloaf! I've never heard that one before. =)


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StarryHost
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Reged: 01/13/09

Loc: Vista, CA
Re: First Light: 10" F11 Report new [Re: glennnnnnn]
      #5565219 - 12/11/12 12:29 AM

Tim,
I love that VW Cheerie Picker. I hope I can get one in red!

Jack


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Ed Jones
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Re: First Light: 10" F11 Report new [Re: StarryHost]
      #5565711 - 12/11/12 10:52 AM

Jack,
How did you mount your Chief lenses?


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StarryHost
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Loc: Vista, CA
Re: First Light: 10" F11 Report new [Re: Ed Jones]
      #5566169 - 12/11/12 03:46 PM

Ed,
Good question. The lenses are all fixed mounted in one upper OTA unit. I can't find a picture this moment so I'll explain.

The theory is that if the prescription of distances and tilts is known to a high degree, then we should be able to build a fixed box to house the upper elements (secondary, L1, L2, focuser). Each unit (secondary, L1, L2, focuser) is attached to an aluminum plate which has tabs on the edges which fit like a puzzle snugly into the square aluminum tube of the upper OTA (or lens box or whatever you want to call it). The thickness of the plates is taken into account for the overall distances and tilts and decenters. Mike and Dave and Kevin have all been extremely generous and helpful. The secondary and the mirror have been siliconed while the focuser is screwed (so to speak).

I have had many challenges to this point with the Chief, but much of that is because of both the rigorous demands of the placements of the optics and my skills and shop tools. To eliminate errors with my adjustable lens holders, I went the fixed route.

Now that I have gotten the newt version working, I have eliminated many flexures in the mount that I had and platform. The newt mount can actually now recieve my Chief ladder and Upper OTA (lens box).

Other difficulties I continue to work on are flexure in the mounting of the secondary, the ladder and the focuser. My problem is that a shift of only 1/16th of an inch from perfect square in any of these components sends my light beam over an inch off center by the time it traverses it's 112" light path.

I believe I have nailed the angle of the secondary, but my focuser mount remains a little wobbly. Again, for a newt the minute wobble is nothing at all, but I worry about the compounded impact of a small error in the focuser board and the secondary and finally any twisting of the ladder.

So here is where I am. I am continuing to finish the newt and will begin my outreaches with it (this is a ministry scope for me above all else) and I will coninue to nail one Chief variable at a time. The Chief variables I need to nail are:
--Twisting of the ladder at every alt level
--Movement of the focuser
--Angle of the secondary to the lenses (I may have finished this part).

Wouldn't it be fun to have a scope that converts from a newt to a Chief and back again in a few minutes?

Thanks for checking in,
Jack


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Ed Jones
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Re: First Light: 10" F11 Report new [Re: StarryHost]
      #5566343 - 12/11/12 05:32 PM

I thought you might have, I would have highy recommended against doing that. When make everything fixed the tolerances are tighter and you give up degrees of freedom in alignment. Making things fixed works in theory but you're up against more tolerances; if it works great, if not what do you do then? I make a holder that holds both lenses fixed relative to each other but the holder can rotate which gives a needed degree of freedom.

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