Skywatcher Dob questions

[John]

Its worth thinking carefully about the aperture. A couple of inches larger sounds tempting and sometimes does not cost much more but when you get the thing setup you can get a shock

My 12 inch is as large as I can go given my need for a scope that can be setup single handed with relative ease and speed, taken down again equally speedily (rain clouds can move fast at times !) and can be moved around my garden fairly readilly to circumvent trees, neighbours houses, street lights etc, etc. Oh, and my scope lives in the dining room and there is only so far that I can push things with my other half

This is me with "big bertha" as my other half calls it, at an outreach event:

 

[ukskies]

9 hours ago, John said:

The only drawbacks in buying a new OO (if that is what you are thinking) are:

- They are expensive - much more expensive than the Skywatcher, GSO or Bresser equivalent.

- They can depreciate quickly so make better value used buys I feel.

- The service from OO has " mixed " reputation.

 

Yes they are more expensive but then you do get a better focusser than the SW one, you also get a cooling fan and better optics if going for the 10th wave option.

I've seen a few for sale used in the past on ABS and they seem to go for less than half price.

The service stories are a bit worrying, I've also read of some tests on the optics that pointed to the interferometry report not being quite accurate but I guess any manufacturer of anything will have tolerances and sometimes things aren't what they appear top be.

[John]

2 minutes ago, ukskies said:

I thought it looked like the long version, do you not get any coma with that then john? Or is it just acceptible?

I can probably just see a touch of coma right at the edges of the field of view with my 100 degree eyepieces, if I really try hard and look for it. It will be there no doubt (according to optical theory) but I honestly don't find it intrusive in any way. 

This is just my experience over the 7 years that I've owned the scope. My dob is not a "perfect scope" of course but I feel that its a good one and it suits me just fine

 

[Barry-W-Fenner]

9 minutes ago, John said:

Its worth thinking carefully about the aperture. A couple of inches larger sounds tempting and sometimes does not cost much more but when you get the thing setup you can get a shock

My 12 inch is as large as I can go given my need for a scope that can be setup single handed with relative ease and speed, taken down again equally speedily (rain clouds can move fast at times !) and can be moved around my garden fairly readilly to circumvent trees, neighbours houses, street lights etc, etc. Oh, and my scope lives in the dining room and there is only so far that I can push things with my other half

This is me with "big bertha" as my other half calls it, at an outreach event:

 

If I ever decide to upgrade my scope I think a 12" would be the largest practical size. I can't see any point going from an 8 to a 10 an any more than 12 would be difficult to move around the garden.

do you take you 12 from the dining room in one piece John? Or do you take it apart. If you take it apart I assume you also do this when relocating in the garden?

 

Regards

Baz

 

[ukskies]

8 hours ago, Raph-in-the-sky said:

I would say that up to 10'' is transportable, however I don't think collapsible makes it more transportable... It might be useful for storage though.

But if you don't want to delay the Tak for too long I would go with 8''. An 8'' dob is amazing value for money and views in a 10'' are only marginally better.

Hi thanks fotr the advice, I was considering a used SW 12" and thinking the collapsible idea would make things easier to transport. That scope has a FL of 1500mm and collapsed would fit across the back seat of my car with the base in the boot.

[John]

6 minutes ago, Barry-W-Fenner said:

If I ever decide to upgrade my scope I think a 12" would be the largest practical size. I can't see any point going from an 8 to a 10 an any more than 12 would be difficult to move around the garden.

do you take you 12 from the dining room in one piece John? Or do you take it apart. If you take it apart I assume you also do this when relocating in the garden?

 

Regards

Baz

 

I lift it in two sections Baz. The optical tube just lifts off the mount using the "wheels" as handles. Base goes out first then the scope plonks on top then a few bits and pieces are attached while it cools.

I can move the whole thing a short distance in one piece (using a sort of sideways shuffle) but I have a weak back which I'm taking good care of so I try and minimise that. 

it is said that a 4 inch increase is needed to see a noticable difference when you get to the mid-aperture ranges.

 

[Barry-W-Fenner]

That's another great feature of the mount you have John, I didn't realise that you just removed the tube with the alt rings still attached. I thought you would need to slide the tube back out of the rings. That's a nice touch for taking apart separately.

I am in the same boat with my back, I do have a nasty habit of just lifting the whole scope up by the handles and carrying it straight out,  I find the skywatcher base a bit of a chore to unscrew and screw the tube back on. I carry it out and put it down gently so hopefully this is no issue for the scope.

Thanks for the advise regarding the size jump, that confirms what I was thinking regarding the 10" what is the best place to keep our eyes on for a used orion?

Thank you

baz

Edited February 4, 2020 by Barry-W-Fenner

[johninderby]

That’s what I like about the Bresser. Just pick up the tube using the alt bearings as handles.

Edited February 4, 2020 by johninderby

[Barry-W-Fenner]

12 minutes ago, johninderby said:

That’s what I like about the Bresser. Just pick up the tube using the alt bearings as handles.

So the tube and alt bearings literally sit in the mount unfixed. It all just balances in place?

Baz

[Marvin Jenkins]

1 minute ago, Barry-W-Fenner said:

So the tube and alt bearings literally sit in the mount unfixed. It all just balances in place?

Baz

I have to say I don’t have one but a mate of mine is just about to buy. One of his reasons is not just the quality for price it’s that the OTA is in tube rings so you can take it out of the Dob mount and put it on an eq mount.

Use and time will tell or course.

Marv

[johninderby]

The Bresser uses tube rings as well. Does make balancing the OTA easy. The OTA can be moved with a fingertip but stays in place.

 

Edited February 4, 2020 by johninderby

[ukskies]

56 minutes ago, johninderby said:

The Bresser uses tube rings as well. Does make balancing the OTA easy. The OTA can be moved with a fingertip but stays in place.

 

I do like the look of those big alt bearings, That's a nice looking scope John.

[JOC]

There were some comments regarding weights above.  This issue is very valud and I have encountered problems with the motor in my goto SW not being capable of lifting the scope up when it is unevenly weighted with a large EP.  I find the solution is to only add in the larger EP once the scope has arrived on target as I never got around to adding magnets and weights.

[fiestazetecmk2]

It's a difficult thing trying to steady and balance a dob of any size really.

That's what made me modify my dob.it has made a huge difference. The stability and control is so much better.Even with high magnification eyepieces. Just remember a dob is for life Not just for Xmas. 

Edited February 4, 2020 by fiestazetecmk2
Info

[NGC 1502]

9 hours ago, fiestazetecmk2 said:

It's a difficult thing trying to steady and balance a dob of any size really.

That's what made me modify my dob.it has made a huge difference. The stability and control is so much better.Even with high magnification eyepieces. Just remember a dob is for life Not just for Xmas. 

 

 

Interesting mods, obviously slow motions for tracking.   Any chance of showing details please ?   Or perhaps a new thread in DIY section ?

Cheers, Ed.

 

Edited February 5, 2020 by NGC 1502
correction

[NGC 1502]

For those who understandably would like to buy used, there’s currently a nice  OO 10” Dob for sale on here......

Looks like a good opportunity for someone.

Ed.

[ukskies]

Well thank you all for the advice it's all been very much appreciated.

I have today been to see the Skywatcher 300p flex tube synscan and found it very manageable, so much so I brought it home. 😀

Mrs me was giving me a little static this morning as I had warned her it was a big scope however she must have softened once she saw it because by the time I got the payment sorted and loaded the scope she had named it !! That's a result right there!

The scope looks in very good condition tho there are a couple of marks on it there's nothing I can't sort out very easily. I have bought it second hand as it is to be a project scope and will have a good few upgrades before it is complete.

Anyway the scope came with a few extras and I got it for a really good price so I have no complaints.

With no more chat, here's R2-D2..........

[ukskies]

A few more.......

 

 

[mert]

Nice scope, I saw it on ABS. I had one a few years back and sold it on, I wish I had kept it.

[ukskies]

37 minutes ago, mert said:

Nice scope, I saw it on ABS. I had one a few years back and sold it on, I wish I had kept it.

Yes it was on ABS, just up the road from one of our dog walking haunts so it was easy to combine the two this morning. Less easy was combining the two in the car tho, poor lad didn't have much room for the return journey!

[ukskies]

I must apologise to you all for the coming 8 weeks or so of continuous cloud, it will be down to me for bringing the curse to you all. After that i will attempt a first light report.

The scope came without any eyepieces so I'm going to start another thread for recommendations.

[mert]

5 hours ago, ukskies said:

I must apologise to you all for the coming 8 weeks or so of continuous cloud, it will be down to me for bringing the curse to you all. After that i will attempt a first light report.

The scope came without any eyepieces so I'm going to start another thread for recommendations.

It will be my fault also. I am picking up a big dob tomorrow.