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Considering the AP900GTO
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Saad Abbasi
Hi all,
First post in this user group. I've been considering the AP900GTO for some time now. The OTAs I currently own are a Takahashi FSQ-85ED and a AT RC8 - both of which are hardly a challenge for the AP900GTO. I will have these OTAs for quite sometime and will probably upgrade to a 12" CDK or RC in the next few years (read 5+ years). Will the 900GTO be able to handle, say, Planewave 12.5" CDK which weighs 46 lbs and a focal length of ~2500mm? What about a C14? I would have loved the AP1200 but that's no longer an option. The AP1600 is just too big for me to lug around. i don't have an observatory (but long terms plans include one.), so I"ll have to setup the mount every time. I was also considering the Paramount MX but the AP900GTO has a proven track record. The new polar scope, it seems, will polar alignment a piece of cake too. |
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No problem, the AP-900 will handle both these scopes and the weight is very nice compared to the larger mount.
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But, if the weight is not an issue, then the AP-1200 or AP-1600 would be a good choice, they have a lot more capacity. Floyd --- In ap-gto@..., "Saad Abbasi" <nil.recurring@...> wrote:
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Jim Jones
Saad
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I had a C14 on a Losmandy G11 for one observing sessions. It worked kinda. But in the end it was just too much weight. I bought an AP1200 last fall and am much happier. It is very nice to be able to add what ever gizmo's I want to the mount without worrying about the weight. I don't know anything about the AP900. Others will have to comment on it. But if you really want a AP1200, I suspect a number of them will be available on the used market as people upgrade to the AP1600. Jim Jones Saad Abbasi wrote: Hi all, |
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topboxman
From Astro-Physics web site, it says the capaicty is 70lbs and it
quotes: "Approximately 70 lb. (31.8 kg) scope and accessories (not including counterweights), depending on length. Recommended for: Astro-Physics and similar fast refractors up to 180 mm f9, 12" Cassegrains and 12-14" Ritchey-Chretiens, 12.5" CDKs. These are only guidelines. Some telescopes are very long for their weight or heavy for their size and will require a larger mount. Remember also that imaging requirements are more rigid than visual observation." Notice it included 12.5CDK. Peter --- In ap-gto@..., "bakersfieldbiker" <fblue@...> wrote: very nice compared to the larger mount. But, if the weight is not an issue, then the AP-1200 or AP-1600 wouldbe a good choice, they have a lot more capacity. Floydfor some time now. The OTAs I currently own are a Takahashi FSQ-85ED and a AT RC8 - both of which are hardly a challenge for the AP900GTO. to a 12" CDK or RC in the next few years (read 5+ years). weighs 46 lbs and a focal length of ~2500mm? AP1600 is just too big for me to lug around. i don't have an observatory (but long terms plans include one.), so I"ll have to setup the mount every time. I was also considering the Paramount MX but the AP900GTO has a proven track record. The new polar scope, it seems, will polar alignment a piece of cake too. |
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Joe Zeglinski
Hi Saad,
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I'm currently testing (challenging ?) ... my AP-900 carrying capacity - with an RCOS RC14.5" (truss tube) on it (65 lbs, bare without accessories). Works just fine, in house. However, the standard AP-900 cwt. bar was not quite enough to completely balance the scope. - even by adding ALL the weights I had at the time - ( AP-18 lb + AP-10 lb + 2x Cassady 21.8 lb. ). This 65 lb scope was only very slightly heavy, but the cwts were within already within an inch of the end of the bar, and no room left on the bar, above, to add any more - (maybe one more AP-10 lb, but it would have much less effect up there)! My solution was to buy the AP 8.5" Extension Bar. This adds another 6.6 lbs of its own, to the end, as a cwt., which provided me just enough extra length to decrease the previous cwts to just three from four, (one AP-18lb and 2x Cassady 21.8 lb ) - and the 65 lb scope was then fully balanced. I have heard that having large cwts lower the bar, can make the system slow to react to small guiding changes, because of inertia. Something to consider, but I haven't tested this yet. Plus, all the cwts. were now in the "middle" of the bar (190 mm of bar left below the stack, and 134 mm above the stack) - so there is ample cwt. adjustment space for cameras, like my STL-11000, and/or some kind of guide scope - with this same set of just three. Then, there is also now plenty of room to add more cwts. if needed. I'm a happy astro-camper! I meant to post some pics to the group, when I finish my testing. I am quite surprised how well the AP-900 performs with such a load. This is probably at the outer limits for the AP-900, but it still works just fine. Mind you, I am using a truss tube scope, so a "solid composite fibre" like your CDK 12.5 scope would face some wind resistance, unless it is in an observatory, just like a refractor. The other thing to consider is that with such weight, and possibly size, you have to be careful about not pushing on the OTA, since it can slip its clutches, and you will have to align your scope again - an AP-1200 has larger diameter clutch, so it shouldn't slip a clutch as easily. However, I think your CDK 12.5" should be fine - others have used similar Meade & Celestron in this range. Of course, it also depends on how heavy a potential guide scope might be - especially since it will influence the balance much more, since it will sit on top of the CDK, and thus create much more leverage, even for its small weight. My intent, when I decided on this AP-900 was to just use it as a portable mount for a smaller scope, but it seems to be able to satisfy short term observatory needs as well. I may eventually upgrade to a (now) "used" AP-1200, or a brand new AP-1600, if the used 1200 market doesn't drop enough, but it is comforting to find out that there is no longer a hurry - the AP-900 seems to have worked out fine for the moment, thanks to Roland's unsurpassed product design and superb quality. I guess the common advice is that if ou plan on a fixed observatory system, go for the larger AP-1200/1600, but for portability the AP-900 would be better. Of course, a CDK-12.6 at 65 lbs isn't ... that portable - its luggage alone might weigh more ;-) Joe Z. -----Original Message-----
From: Saad Abbasi Sent: Thursday, April 26, 2012 4:19 PM To: ap-gto@... Subject: [ap-gto] Considering the AP900GTO Hi all, First post in this user group. I've been considering the AP900GTO for some time now. The OTAs I currently own are a Takahashi FSQ-85ED and a AT RC8 - both of which are hardly a challenge for the AP900GTO. I will have these OTAs for quite sometime and will probably upgrade to a 12" CDK or RC in the next few years (read 5+ years). Will the 900GTO be able to handle, say, Planewave 12.5" CDK which weighs 46 lbs and a focal length of ~2500mm? What about a C14? I would have loved the AP1200 but that's no longer an option. The AP1600 is just too big for me to lug around. i don't have an observatory (but long terms plans include one.), so I"ll have to setup the mount every time. I was also considering the Paramount MX but the AP900GTO has a proven track record. The new polar scope, it seems, will polar alignment a piece of cake too. ------------------------------------ To UNSUBSCRIBE, or for general information on the ap-gto list see http://groups.yahoo.com/group/ap-gtoYahoo! Groups Links |
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Philip Perkins <ppml5@...>
I had a C14 on a Losmandy G11 for one observing sessions. It workedWell intended input I'm sure but there is no comparison between a G11 and the 900GTO. The 900GTO is in a different class altogether in terms of its load capacity, stability, tracking accuracy, and ruggedness. The PE on my 900GTO is so low that I have never had to train it. It has carried my 12.5" RCOS + accessories (65lbs, 3020mm FL) with real precision over the past twelve years, again with no PE correction at all. You can see some of these "toughest test" images on my galaxy pages: http://www.astrocruise.com/galaxies/galaxies.htm Philip -- Philip Perkins <ppml5@...> Wiltshire UK & Luberon France www.astrocruise.com -- Note: the above email address may change in future. To find my latest email address please visit: www.astrocruise.com and click the "Send Email" link. -- |
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Jim Jones
Phillip
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I don't think I made a comparison between the Losmandy and the AP 900. In fact I specifically stated that I didn't know anything about the AP-900. My point was that not having enough capacity is miserable indeed. For me it was worth it to get the extra load carrying capacity of the AP1200. Your comments were well intentioned I'm sure. Jim Jones Philip Perkins wrote: I had a C14 on a Losmandy G11 for one observing sessions. It workedWell intended input I'm sure but there is no comparison between a G11 and the 900GTO. The 900GTO is in a different class altogether in terms of its load capacity, stability, tracking accuracy, and ruggedness. The PE on my 900GTO is so low that I have never had to train it. It has carried my 12.5" RCOS + accessories (65lbs, 3020mm FL) with real precision over the past twelve years, again with no PE correction at all. You can see some of these "toughest test" images on my galaxy pages: |
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Hi Philip,
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I have owned a G-11 and still own a GM-8 and can state that the G-11 is not in the same class as the AP-900 or the MI-250. It is a nice mount, but no where near the same dispite the stated capacity. Floyd --- In ap-gto@..., Philip Perkins <ppml5@...> wrote:
I had a C14 on a Losmandy G11 for one observing sessions. It workedWell intended input I'm sure but there is no comparison between a |
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The OTAs and your proposed 12.5" CDK would be a piece of cake for the 900. The C14 should be ok but may be a bit of a challenge in a breeze.
Don ________________________________ From: Saad Abbasi <nil.recurring@...> To: ap-gto@... Sent: Thursday, April 26, 2012 2:19:01 PM Subject: [ap-gto] Considering the AP900GTO Hi all, First post in this user group. I've been considering the AP900GTO for some time now. The OTAs I currently own are a Takahashi FSQ-85ED and a AT RC8 - both of which are hardly a challenge for the AP900GTO. I will have these OTAs for quite sometime and will probably upgrade to a 12" CDK or RC in the next few years (read 5+ years). Will the 900GTO be able to handle, say, Planewave 12.5" CDK which weighs 46 lbs and a focal length of ~2500mm? What about a C14? I would have loved the AP1200 but that's no longer an option. The AP1600 is just too big for me to lug around. i don't have an observatory (but long terms plans include one.), so I"ll have to setup the mount every time. I was also considering the Paramount MX but the AP900GTO has a proven track record. The new polar scope, it seems, will polar alignment a piece of cake too. |
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