Skywatcher Dob questions

[ukskies]

5 hours ago, NGC 1502 said:

I too like the OO Dob mounts.  Mine work well and tracking at over 200x is fine.  But I’ve had particle board Dob mounts, and prior to assembly it’s a good idea to seal the raw edges with thin wood glue, let that dry then a second coat. After assembly the joints can be sealed with white mastic being careful to make a neat job.  These simple precautions keep out the damp and give a long life.  It wouldn’t be hard to take an existing mount apart to do the above.

Ed.

 

Thanks Ed, another vote for the OO and helpful info about damp proofing the MDF bases. I think I'm swaying in favour of the OO atm.

[ukskies]

5 hours ago, John said:

 I've owned dobs made by GSO 8 inch, Meade 12 inch (actually another GSO made one), Skywatcher (8 and 10 inch) and Orion Optics (10 and 12 inch). They all worked pretty well out of the box except the Meade that needed more fettling to get it satisfying to use. All dobs seem to benefit from a little tweaking here and there to get the best from them though.

The worst thing about the MDF bases is that they are heavy. My current Orion Optics 12 inch dob has a base made by a fellow SGL'er from quality plywood but to a similar pattern that Orion Optics use for their mounts. It's worked wonderfully since the day it was delivered.

 

That's a lovely compact looking mount John, I can see the similarity to the OO one and I too like the sliding weight setup.👍

What's the focal length of that one please?

Edited February 4, 2020 by ukskies

[ukskies]

5 hours ago, NGC 1502 said:

I too like the OO Dob mounts.  Mine work well and tracking at over 200x is fine.  But I’ve had particle board Dob mounts, and prior to assembly it’s a good idea to seal the raw edges with thin wood glue, let that dry then a second coat. After assembly the joints can be sealed with white mastic being careful to make a neat job.  These simple precautions keep out the damp and give a long life.  It wouldn’t be hard to take an existing mount apart to do the above.

Ed.

 

Hi Ed, just re read your post, do you have tracking on your OO dob mount then? 

If so do you have any pics or details please?

[johninderby]

It is possible to fit a GOTO system to an OO mount but not cheap. The StellarCat system is one option. Here’s a lttle something I built a few years ago.

[NGC 1502]

1 hour ago, ukskies said:

Hi Ed, just re read your post, do you have tracking on your OO dob mount then? 

If so do you have any pics or details please?

Hi Gary, no I don’t have tracking in the accepted meaning.  My tracking is achieved manually.   Both my OO Dob mounts work well, one being a bit better than the other.  The best one is for my 8” f6 1/10 wave, manually tracks beautifully at high power making it an absolute pleasure to use with wonderfully sharp views.

Manually tracking a Dob is a learning curve at first, then it becomes just like steering a car - you do that automatically without fuss.   To track at high elevation is a bit different, the azimuth movement is more of a “twist” of the mount.

A “sticky” Dob is a right royal pain, a silky smooth Dob is a joy to use.

Ed.

[fiestazetecmk2]

Myself I chose the skywatcher skyliner 8" dob .I did look at larger dobs but as I'm getting on in years didn't want a dob I couldn't manage to take out myself.

I've always been very happy with my dob.although I have done a few mods to it.

It's no good buying a large dob that you'll never use or cannot manage .There isn't much I'm missing out on in visual terms.

Im glad I chose the 8".it's very manageable. I get fabulous veiws .and most of all I use it Alot. The best thing is now I'd never sell it.Don't be put off by the smaller dobs.You will get good views .

Just remember Size does  matter!! why buy something you can't manage. Just to  sit in the corner .!!!

[John]

3 hours ago, Marvin Jenkins said:

Hi John, I am guessing but is that sliding counter weight on a rail at the back end?

I noticed something similar on #johninderby Skywatcher but couldn’t see it clearly.

If it is then a very neat and elegant solution. Beats hanging a small dumbbell weight off the back end which I have seen in a few pictures of the past.

Marv

Its a magnetic kitchen knife rack fastened to the tube. I have two weights (old counterweights) of different weights and 2 points on the rack where I can put them so that gives me enough variations to handle all my eyepieces including the "monsters"

With Skywatcher and (maybe) Bresser have steel tubes so you can put magnetic weights directly onto them. Orion Optics use aluminum tubes (which is why they are lighter).

[johninderby]

A simple way on an OO dob is to bolt a Skywatcher dovetail bar onto the tube then use a small saddle with weights attached.

Edited February 4, 2020 by johninderby

[John]

51 minutes ago, fiestazetecmk2 said:

....Just remember Size does  matter!! why buy something you can't manage. Just to  sit in the corner .!!!

Very sensible point !!!

I had a Meade Lightbridge 12 inch and that weighed around 80 lbs. It was a decent scope (when I'd modded it) but just too heavy to be easy to setup so it did not get used much. My Orion Optics 12 inch weighs over 20lbs less so gets used all the time.

 

 

[johninderby]

I’ve settled on the Bresser 10” for now. Still easy to carry around.

Had a 16” Meade Lightbridge but it was a big heavy lump and a right pain to move about. In the end went to Moonshane..

[John]

3 hours ago, ukskies said:

..What's the focal length of that one please?

Thanks.

The focal length is 1600mm so its an F/5.3. I wanted something that would not need a coma corrector. 

[John]

3 hours ago, ukskies said:

Thanks Ed, another vote for the OO and helpful info about damp proofing the MDF bases. I think I'm swaying in favour of the OO atm.

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.

 

[johninderby]

Might replace the Bresser base with a nice OO style hardwood ply one someday but of course keeping the Bresser Alt bearings. 🤔🙂

Edited February 4, 2020 by johninderby

[Raph-in-the-sky]

On 02/02/2020 at 21:12, ukskies said:

Hi everyone,

I am currently scopeless and live in light polluted skies in town. I have been going around in circles trying to choose a scope that I will use regularly. I am thinking about a Takahashi refractor later in the year but funding is not in place yet and may take several months, meanwhile I thought of a second scope to compliment the refractor in the shape of a used reflector.

I'm considering purchasing a dob mainly for cost v aperture. I'm a bit daunted by the size and transportability of a larger dob and am considering a skywatcher collapsible one. This looks ideal as it will fit in the car so I can transport it to a dark sky location sometimes.

Does anyone on here have one that they use regularly and if so is it a good design or are there collimation problems with this design?

Also I would like to know what is the largest size one may consider as transportable? Finally I like the idea of tracking for higher power viewing of solar system objects and wonder what your thoughts are about the synscan.

Gary

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.

[JOC]

16 hours ago, ukskies said:

My point about the collimation was really during use, is the lockup really solid once set up?

Absolutely rock solid you need not worry on that account - they kind of click into place.  FWIW here is my 8" flex tube just so you can see it:

 

I've since added the SW WiFi dongle which I think is a good upgrade from the original hand-held unit and a RACI/RDF finder combo.  HTH

[JonCarleton]

Woah!  Wait a bit!  The SkyWatcher 10" now comes with built-in WiFi.  They actually sold me a dongle because the vendor didn't know.  When I opened things up, there was a a little note from SkyWatcher saying it was built-in, so I sent the dongle back.  I can say that the built-in WiFi works very well.

 

[ukskies]

12 hours ago, johninderby said:

It is possible to fit a GOTO system to an OO mount but not cheap. The StellarCat system is one option. Here’s a lttle something I built a few years ago.

That looks a very professional job John, well done.👏

[ukskies]

10 hours ago, NGC 1502 said:

Hi Gary, no I don’t have tracking in the accepted meaning.  My tracking is achieved manually.   Both my OO Dob mounts work well, one being a bit better than the other.  The best one is for my 8” f6 1/10 wave, manually tracks beautifully at high power making it an absolute pleasure to use with wonderfully sharp views.

Manually tracking a Dob is a learning curve at first, then it becomes just like steering a car - you do that automatically without fuss.   To track at high elevation is a bit different, the azimuth movement is more of a “twist” of the mount.

A “sticky” Dob is a right royal pain, a silky smooth Dob is a joy to use.

Ed.

I've never owned a Dob Ed but just assumed tracking would make things easier at higher power.

I guess ill have to learn the proper way!

[ukskies]

9 hours ago, John said:

Its a magnetic kitchen knife rack fastened to the tube. I have two weights (old counterweights) of different weights and 2 points on the rack where I can put them so that gives me enough variations to handle all my eyepieces including the "monsters"

With Skywatcher and (maybe) Bresser have steel tubes so you can put magnetic weights directly onto them. Orion Optics use aluminum tubes (which is why they are lighter).

What a simple and clever idea!

[johninderby]

Can’t emphasize  too much the importance of a dob that moves easily but not too easily and has no “Stiction”.

Edited February 4, 2020 by johninderby

[ukskies]

9 hours ago, johninderby said:

A simple way on an OO dob is to bolt a Skywatcher dovetail bar onto the tube then use a small saddle with weights attached.

That's a very useful solution too.

[John]

6 minutes ago, johninderby said:

Can’t emphasize  too much the importance of a dob that moves easily but not too easily and has no “Stiction”.

True.  It needs to remain pointing precisely at the target though changes of eyepiece, filter etc and not to move too readily if there is a breeze. Then move as smooth as butter to the next target. It's tougher than it sounds to get this "just right" but when you use a scope you sure know when it isn't

 

 

[ukskies]

9 hours ago, John said:

Very sensible point !!!

I had a Meade Lightbridge 12 inch and that weighed around 80 lbs. It was a decent scope (when I'd modded it) but just too heavy to be easy to setup so it did not get used much. My Orion Optics 12 inch weighs over 20lbs less so gets used all the time.

 

 

That's a very worthwhile weight saving there John. I'm favouring the OO more all the while.

[ukskies]

9 hours ago, johninderby said:

I’ve settled on the Bresser 10” for now. Still easy to carry around.

Had a 16” Meade Lightbridge but it was a big heavy lump and a right pain to move about. In the end went to Moonshane..

I wouldn't consider anything in that size other than a super lightweight design but they cost a lot of money and that kind of takes the Dob out of things, IMHO of course. 

[ukskies]

9 hours ago, John said:

Thanks.

The focal length is 1600mm so its an F/5.3. I wanted something that would not need a coma corrector. 

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