The mysterious specs of the Skywatcher Dobsonian beasts

[Ab Umbra Lumen]

Hi everyone!

I've decided to get my first "serious" equipment, finally setting up for a choice between two models: the Skywatcher dobsonian 12" (300p) or 14" (350p) Flextube GOTO (Synscan). Yes, beasts. Yes, weight and complications rather than an SCT. But the dobsonians are calling in the dark sky... I think I am doomed :-)

The only problem I am having for a final decision is that the full size/weight speciifications of these beauties/beasts are missing and appartently a hidden secret.

The setting: house in the Dolomites Mountains (ca. 1400m alt.), where I plan to get the "beast" straight out of the garage and outside the house. So the plan is to leave the base permanently in the garage, often with the OTA on it, then getting it out with a trolley or some other gizmo, just few meters away, powered with an extension wire from the garage. I'd like not to assume any help, that is to say, to be able to do it alone (so, 16" is out of question).

But for these "beasts" weight and size are also a factor to consider, and I couldn't find any official data on the spec sheets. Reading here and there, there are rumors that for instance the 14" GOTO base is so heavy (50kg?) that is almost impossible to handle alone unless you have superpowers, whereas the OTAs are more or less the same size (21-23Kg?) and manageable. The sizes of the base is also a mystery (rumors are the 14" cannot be taken thru normal doors), and that is also helpful to know how it could be set up on a rolling base, and how much room would it take in a corner. Before you ask: yes, taking out GOTO takes out some weight and money too, but please don't ask me to give it up :-)

So, could someone please give a final word about:

1) the WEIGHT of the base (12" and 14" GOTO versions, weighting more than the normal versions)

2) the DIAMETER of the base (always 12" and 14" GOTO versions)

Of course if anybody wants to add some other opinion on how easy these would be to handle in the setting described above, the more info the better :-)

Thanks so much!!

[ronin]

For the 12" Skywatcher give: Shipping Weight       33 + 23kg

I presume that the 23Kg is the base but that weight as said includes the box and packaging, and what that amount to is a bit of a guess. Suppose 5Kg for packaging is reasonable so 18Kg for the base seems fair.

The 14" is given as; Shipping Weight 43+26+11kg, 3 cartons. Again I guess 2 is the base so 20Kg for the base alone seems fair.

Skywatcher do not go into the detailed sizes and weights for the dimensions, I would say they would end up having to supply too many. You need someone that has one, but I am not sure they will have accurate weights, likely reasonable estimates.

Might help, if you do not already have it: http://www.skywatcher.com/_english/01_products/01_list.php?cid=5

[Ab Umbra Lumen]

Thanks Ronin, in fact looking at the shipment sizes can be a good "investigative" way to guess weights, at least approximately. Another problem is that figures can vary from site to site, and it's unclear who is right: the best would be someone (owners) to finally shed some light on this mysterious numbers.

Anyway, adding to your wise calculations, I include below the most reliable figures I have found so far, so even if no owner replies at least there is some information and reference for anybody who wants to have more detailed information on these scopes, now and in the future.

Numbers are relative to the large scopes Skywatcher dobson GOTO 12"/14"/16" (300p/350p/400p) respectively:
Base weight:  36Kg/50Kg/55Kg (source: teleskop-express)
OTA weight: 27Kg/23.5Kg/38Kg (source: teleskop-express)
Base diameter:  63,2cm/77,5cm/84,2cm (sources: 365astronomy / http://www.iceinspace.com.au/forum/archive/index.php/t-73854.html / teleskop-express)

Some considerations (*IF* these numbers are correct):

1) There is a huge increase in base weight from passing from the 12" to the 14", the 16" then is almost the same; 50Kg (!) is quite a heavy beast, which means probably it cannot be easily lifted and should be permanently put on some wheeled base.
2) The OTA weight, on the other hand, even decreases from 12" to 14" (!), making it even more portable: so, separating the OTA from the mount is a handy operation both in the 12" and 14", not so for the 16"
3) Diameter again increases a lot from 12" to 14" (+14,3cm), less than from 14" to 16" (+6,7cm), which could also explain the problem with the base weights; this makes the 14" at risk from passing thru doors (door's aperture range from 70 to 80cm)

So final usability considerations (again, *IF* these numbers are correct):

12": base can pass thru doors, both base and OTA ok to manage by hand alone
14": base cannot pass thru doors, base too heavy to lift alone (!), OTA ok to manage alone
16": base cannot pass thru doors, base too heavy to lift alone, OTA dangerously heavy to manage alone
 

Personally, this leaves the 16" out of question, as I said. Regarding the 12" vs 14", the main problem to think about is the huge base weight. Even if using a wheeled support, I'd like to be able to take the base over and out from it alone, so to be able to land the base on the ground rather than having it permanently attached to an underlying wheeled base (even with blocking wheels).
Not an easy choice...