dothead
scholastic sledgehammer
Reged: 08/13/08
Loc: Heidelberg, Germany
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Ultimate capacity yet portable mount: AP 2400GTO ?
#4419423 - 03/01/11 03:39 PM
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...as an intermediate mount between the 1200 (81 lbs) and the 3600 (205 lbs), something like a 130ish lbs Astro-Physics mount would be still transportable for a determined individual (RA-unit approx. 80 lbs as the heaviest part), and would handle loooong refractors, like an 8" f/20, or big & heavy imaging scopes, like the CDK 17 & 20.
Do you think there's a "gap" between the 1200 and the 3600 ?
Could Astro-Physics touch a market segment with a 130 lbs "2400GTO" mount ?
Regards,
Ralph
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LLEEGE
True Blue
   
Reged: 03/03/05
Loc: Cloud-chester,NY
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Re: Ultimate capacity yet portable mount: AP 2400GTO ?
[Re: dothead]
#4419442 - 03/01/11 03:50 PM
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NEAF is right around the corned. You never know what Roland will unveil. This topic was mentioned on the APUG but RC didn't have much to say on the matter. I wouldn't hold your breath.
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Peter in Reno
Post Laureate
   
Reged: 07/15/08
Loc: Reno, NV
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Re: Ultimate capacity yet portable mount: AP 2400GTO ?
[Re: LLEEGE]
#4419458 - 03/01/11 03:57 PM
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I wouldn't exactly call AP1200 portable and now you want a portable AP2400? AP1200 has a huge carrying capacity of 140 pounds. What monster scope do you want to carry and call it portable?
Peter
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dothead
scholastic sledgehammer
Reged: 08/13/08
Loc: Heidelberg, Germany
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Re: Ultimate capacity yet portable mount: AP 2400GTO ?
[Re: Peter in Reno]
#4419522 - 03/01/11 04:31 PM
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Quote:
"What monster scope do you want to carry and call it portable?"
8" f/20 refractor, with a weight of approx. 50 lbs ("portable" for a single person).
50 lbs may sound "easy" for the 140 lbs - rated AP 1200, but because of the extremely long torque moment arm (OTA length is 14 feet (with dew cap), it will tax the 1200 severely.
Torque moment is identical for:
14 feet 50 lbs OTA 7 feet 100 lbs OTA 3.5 feet 200 lbs OTA (which is beyond the 1200's capacity)
Got my point ?
Regards,
Ralph
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M13 Observer
professor emeritus
Reged: 12/09/06
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Re: Ultimate capacity yet portable mount: AP 2400GTO ?
[Re: dothead]
#4419527 - 03/01/11 04:32 PM
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...as an intermediate mount between the 1200 (81 lbs) and the 3600 (205 lbs), something like a 130ish lbs Astro-Physics mount would be still transportable for a determined individual (RA-unit approx. 80 lbs as the heaviest part), and would handle loooong refractors, like an 8" f/20, or big & heavy imaging scopes, like the CDK 17 & 20.
Do you think there's a "gap" between the 1200 and the 3600 ?
Could Astro-Physics touch a market segment with a 130 lbs "2400GTO" mount ?
Regards,
Ralph
Sounds like the solution to a problem which doesn't exist.
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skybsd
Post Laureate
   
Reged: 02/01/08
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Re: Ultimate capacity yet portable mount: AP 2400GTO ?
[Re: dothead]
#4419529 - 03/01/11 04:33 PM
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Transportable? Even if one could find a way to modularize the mount into more portable components, you're still left with a 140lb scope to think about..,
I'd have thought that if one had the coin for a CDK20, its reasonable to think that one would already have been looking at the el Capitan to begin with 
Regards,
skybsd
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dothead
scholastic sledgehammer
Reged: 08/13/08
Loc: Heidelberg, Germany
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Re: Ultimate capacity yet portable mount: AP 2400GTO ?
[Re: skybsd]
#4419544 - 03/01/11 04:38 PM
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M13, skybsd,
So what about that 8" f/20, 50 lbs refractor ?
The 140 lbs rating applies to short, compact scopes.
Example: I've seen a 30 lbs 6" f/17.5 D&G mounted on the AP 900 (rated for 70 lbs), and the owner remarked that the 900 was barely adequate in holding it stable enough. He suggested the 1200 would be more appropiate for that 30 lbs refractor.
Regards,
Ralph
Edited by dothead (03/01/11 04:39 PM)
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skybsd
Post Laureate
   
Reged: 02/01/08
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Re: Ultimate capacity yet portable mount: AP 2400GTO ?
[Re: dothead]
#4419590 - 03/01/11 04:51 PM
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Hello,
Quote:
The 140 lbs rating applies to short, compact scopes.
I think you misunderstand..,
The CDK20 (bare OTA) weighs 140lbs - even if you find a way to design your theoretical mount to be modular enough to have portable assembly components, you still have to find a way to manage carrying the CDK20.
Regards,
skybsd
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dothead
scholastic sledgehammer
Reged: 08/13/08
Loc: Heidelberg, Germany
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Re: Ultimate capacity yet portable mount: AP 2400GTO ?
[Re: skybsd]
#4419629 - 03/01/11 05:08 PM
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skybsd,
yes, you're right - the CDK 20 was an ill-advised example.
But still, what about that 50 lbs, 8" f/20 (my next scope project) ?
Re portability of the mount: for this 6' 3", 240 lbs guy, 80 lbs (as the heaviest part) is still manageable.
(Germany is the country of beer. A beer crate with 20 0.5 liter bottles weighs in at 19.7 kg = 43.4 lbs. I find it a not too big effort to lift two full beer crates together on a 30"-high table - so I consider it feasible for myself to handle a 80 lbs RA-unit).
Cheers,
Ralph
Edited by dothead (03/01/11 05:59 PM)
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M13 Observer
professor emeritus
Reged: 12/09/06
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Re: Ultimate capacity yet portable mount: AP 2400GTO ?
[Re: dothead]
#4419637 - 03/01/11 05:11 PM
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M13, skybsd,
So what about that 8" f/20, 50 lbs refractor ?
The 140 lbs rating applies to short, compact scopes.
Example: I've seen a 30 lbs 6" f/17.5 D&G mounted on the AP 900 (rated for 70 lbs), and the owner remarked that the 900 was barely adequate in holding it stable enough. He suggested the 1200 would be more appropiate for that 30 lbs refractor.
Regards,
Ralph
http://www.planewave.com/index.php?page=1&id0=1&id=2
Done.
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dothead
scholastic sledgehammer
Reged: 08/13/08
Loc: Heidelberg, Germany
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Re: Ultimate capacity yet portable mount: AP 2400GTO ?
[Re: M13 Observer]
#4419708 - 03/01/11 05:41 PM
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thanks for the link.
Yes, I've also considered the Planewave mount, but the single most heavy component is 96 lbs, which is just that little too much (compared to 80 lbs) which would make it non-transportable for me.
Another candidate I considered is the Mathis Instruments MI-500 mount ( link ), but again, 100 lbs for the polar cone component is those 20 lbs too heavy.
Same with the Knopf MK-70 mount (see Astrolumina): relatively inexpensive for it's capacity, extremely stable, but 220 lbs with two 110 lbs components - not manageable.
What make AP mounts so attractive is that they are designed for maximum strength and rigidity with minimum weight. Mathis Instruments, Knopf, and I suspect also Planewave, didn't intend their mounts to be portable, so they did not minimize weight to achieve portability.
I therefore suspect that a 130 lbs AP2400 mount would exhibit the same strength and rigidity as the 200 lbs MI-500.
Well, maybe I should just pull the trigger and see how the AP1200 would handle the 8" f/20 refractor...
Ralph
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skybsd
Post Laureate
   
Reged: 02/01/08
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Re: Ultimate capacity yet portable mount: AP 2400GTO ?
[Re: dothead]
#4419716 - 03/01/11 05:45 PM
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Well, maybe I should just pull the trigger and see how the AP1200 would handle the 8" f/20 refractor...
Just about the safest bet anyone can make these days 
Regards,
skybsd
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Peter in Reno
Post Laureate
   
Reged: 07/15/08
Loc: Reno, NV
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Re: Ultimate capacity yet portable mount: AP 2400GTO ?
[Re: skybsd]
#4419720 - 03/01/11 05:49 PM
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Have you e-mailed Astro-Physics and asked if your 14 feet long scope can be handled by AP1200? They will be more than happy to answer.
Peter
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dothead
scholastic sledgehammer
Reged: 08/13/08
Loc: Heidelberg, Germany
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Re: Ultimate capacity yet portable mount: AP 2400GTO ?
[Re: skybsd]
#4419728 - 03/01/11 05:53 PM
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well, you're probably right.
Though this mount from German master engineer Manfred Mauz (technical chief of the mechanical department of Munich Observatory) is reported to have a phenomenal stability for it's weight class (88 lbs, two 44 lbs components).
Decisions, decisions...
Ralph
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dothead
scholastic sledgehammer
Reged: 08/13/08
Loc: Heidelberg, Germany
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Re: Ultimate capacity yet portable mount: AP 2400GTO ?
[Re: Peter in Reno]
#4419737 - 03/01/11 05:57 PM
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Not yet.
The 900 is rated for up to 180 mm f/8 refractors, the 1200 for up to 206 mm f/8, the 3600 for up to 12" f/12.
Though I suspect the 1200 could handle a 10" f/12, and I know that at 3RF, a 15" f/12 D&G is mounted on the AP3600.
Another possibility would be the Parallax HD200C (105 lbs, breaks in two components).
Regards,
Ralph
Edited by dothead (03/01/11 06:02 PM)
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Alph
Pooh-Bah
Reged: 11/23/06
Loc: Melmac
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Re: Ultimate capacity yet portable mount: AP 2400GTO ?
[Re: dothead]
#4419855 - 03/01/11 06:58 PM
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Paramount ME is your best bet. The most efficient mounting on Earth. It weighs 87 lbs and it lifts 150 lbs. It is right now on sale for $12,500. It is a steal for anyone from the euro zone.
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skybsd
Post Laureate
   
Reged: 02/01/08
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Re: Ultimate capacity yet portable mount: AP 2400GTO ?
[Re: Alph]
#4419912 - 03/01/11 07:21 PM
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It is right now on sale for $12,500. It is a steal for anyone from the euro zone.
Errr., Nope, nope , and..., no 
Regards,
skybsd
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dothead
scholastic sledgehammer
Reged: 08/13/08
Loc: Heidelberg, Germany
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Re: Ultimate capacity yet portable mount: AP 2400GTO ?
[Re: Alph]
#4419944 - 03/01/11 07:39 PM
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The question is, can we take the manufacturer's stated capacity as gospel ? In the light that some are more conservative than others with their specs.
Don't want to stir a hornet's nest, but are there opinions if the Pm ME ("150lbs cap.") is as beefy as the AP1200 ("140lbs cap.) ?
As a purely visual guy, I don't like to use a labtop in the field (like the Pm ME requires).
Regards,
Ralph
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Peter in Reno
Post Laureate
   
Reged: 07/15/08
Loc: Reno, NV
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Re: Ultimate capacity yet portable mount: AP 2400GTO ?
[Re: dothead]
#4419978 - 03/01/11 08:05 PM
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Astro-Physics capacities are typically for imaging. So if you are a visual observer only, then you can easily increase the capacity to up to double their advertised rate. Ask Astro-Physics first.
Peter
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Alph
Pooh-Bah
Reged: 11/23/06
Loc: Melmac
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Re: Ultimate capacity yet portable mount: AP 2400GTO ?
[Re: skybsd]
#4420070 - 03/01/11 08:39 PM
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Quote:
Quote:
It is right now on sale for $12,500. It is a steal for anyone from the euro zone.
Errr., Nope, nope , and..., no 
Regards,
skybsd
Sure, but he does not have to use an european dealer.
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