Dobsonian woes

[Rob Sellent]

Seeing that you've just got your Mak 127 AZ-Gti, I'd take real advantage of that pleasure and put the scope through its paces for the next season or two. See how you get along with cooling and dew over the winter and spring, whether you like the viewing position, field of view etc as opposed to the dob and so on. That way, when it comes to next year, you'll be able to make a much more informed decision on what you fancy doing, psychologically speaking because of use, you won't have lost so much on the secondhand market and from your knowledge gained be able to help others when they run into similar dilemmas. Everyone wins .

In the meantime, if you're not getting along with the Goto Dob, you can sell and get a 10" manual dob secondhand for a fraction of the price and put the extra cash remaining in your astro-kitty. Don't spend it! You may find that you love the Mak and see no reason to move it on. Certainly its a better planet and double star scope than the linked wide field achro. Or, come next Spring, you may want to try your hand with a frac. Personally, I prefer using ed/apo to achros. My reasoning being if I'm buying a frac I'm not doing so for its aperture but more for its glass. You can pick up something like a SW100ed which is an outstanding OTA with the cash remaining from your Goto Dob.

It's a really nice position to be in. The darker months to put the scopes through their paces, a little extra astro-cash in the kitty and some new potential buys for next year and all the pleasurable research that entails if the fancy takes you 😀    

[Cosmic Geoff]

3 hours ago, -philip- said:

and the WiFi through the phone app seems simpler than Goto.

That remains to be seen. The wifi mounts are still GoTo and I presume you still have to do a 2 or 3 star alignment.  Also having a wifi link instead of a length of curly cable is something else to go wrong. 

[ollypenrice]

Regarding storage and moving, I agree with Peter that a dedicated shelter would be fine for it. Essentially a rainproof 'sentry box' with front opening, very easy and cheap to make. It need not be much bigger than the scope.

There's a transport alternative to the barrow handles which I used successfully in the UK and found in Phil Harrington's book Star Ware. You make a timber false floor for the scope to stand on and attach the ground board to that. This false floor is slightly raised from the ground by four feet like a sofa or armchair. You then use a standard sack truck which you slide under the false floor before tipping it backwards as usual to wheel it about.

If you do go for a wheeled system remember that pneumatic tyres roll vastly more easily than solid ones and transmit a fraction of the vibration. The difference over solid tyres is night and day. (I have to use a solid tyred wheelbarrow here because of endless punctures on thorns but they are absolute murder to push.)

Olly

[Avocette]

I sympathise greatly with you -philip- having myself explored various telescope options over the last seven or eight years. My budget didn’t stretch to buying new, so my purchases were largely steered by local second hand availability and a bit of luck. 

As my signature suggests I presently have assembled an array of four scopes, a 300mm Flextube Dob, 150mm Newt, 150mm Mak and an 80mm ED Frac. The latter three can be mounted on an AZ4 manual mount or an AZ-EQ5 GoTo with two of the three side by side in AZ mode or one in EQ mode. I regularly question myself about which of them I really enjoy most, and which I would I keep and which I would sell if I only had room for one.

During my slow climb up the learning curve, I first owned a Skyliner 200p and after an outbreak of aperture fever I also had a 250px for several months. The latter needed some significant breathing on (cleaning up in general, washing mirrors, swapping out a dodgy focuser etc) and I fitted up both scopes with digital setting circles, Wixey's and leveling bases

I believe I should have been satisfied with the 200p. With the benefit of hindsight, I think most of my observing was limited by the quality of the atmosphere, and my somewhat aging eyes, and not by the equipment. The fact that the 200p and 250px scopes have identical focal lengths should have made it easy to pick out the differences made by the aperture differential. I persuaded myself that the slightly greater 'astigmatism' or was it 'coma' at f4.7 of the 250px required better quality eyepieces than the f5.9 of the 200p. Many authors do suggest that f5 is a threshold, if not a cliff edge, beyond which higher quality eye-pieces are a requirement.

Of course you might buy a good example of a particular telescope model or a rough example of the same model - and it's quite clear that we are required to carry out our own personal quality control of such inexpensive Chinese made equipment.

I have two other opinions on aspects of your dilemma (200p versus 250px Flextube GoTo):

Weight - My 300p Flextube is heavy - about at the limit of my capability to deal with comfortably when divided into base and OTA. I would prefer a fixed tube version except that I like to use a binoviewer for viewing the Moon and planets. This requires me to set the truss rod fittings about 10cm down from their maximum positions to achieve focus through the BV. But the GoTo Flextube scopes are that much heavier, which for me would be beyond comfortable handling on my own.

GoTo accuracy - I have owned an EQ5 Pro with the SynScan v3 handset and more lately the AZ-EQ5 GoTo mount with the v4 handset. Both have tripods can be adjusted to physically level the mount before you begin alignment procedures. I have learned just how critical this leveling is to the success of subsequent alignment and GoTos. The Flextube base has no inherent capability for leveling adjustment so if you plan to make a suitable trolley or truck base for moving it, don't forget to build in some leveling screws, that preferably would reach down to terra firma.

If you can persuade your friend to let you have the 200p back on long term loan you could end up being a happy man!

 

 

[-philip-]

Thank you everyone for your advice, it’s been really useful! 

Well I picked up the Mak today, it was very easy to set up and the SynScan app on my phone seems to be controlling it brilliantly. Clear skies permitting I’ll be using it this week and weekend. I may well buy the 4” frac that fits on the mount too! 

Before I decide one way or another about what to do with my 250 dob i’m going to get it out again this week and have a go at understanding it a bit more. If the WiFi control works for me, buying the WiFi dongle that retrofits the dob might be an option. I’ve already asked my mate if I can have the manual 200p dob back anyway! 

[-philip-]

Ok, so thankful for a couple of hours of clear skies last night using the new 127 Mak, and I had perhaps the best observing I’ve ever had of Jupiter. Much more detail than I’ve had through my dob! Very happy with it, and the SynScan app, it’s definitely a keeper! 

[Stu]

56 minutes ago, -philip- said:

Ok, so thankful for a couple of hours of clear skies last night using the new 127 Mak, and I had perhaps the best observing I’ve ever had of Jupiter. Much more detail than I’ve had through my dob! Very happy with it, and the SynScan app, it’s definitely a keeper! 

Excellent news Philip

 

[fiestazetecmk2]

I agree not everyone wants (or needs)a goto setup.I enjoy my 200p skyliner. Worth every penny.IMHO. 

[-philip-]

20 minutes ago, fiestazetecmk2 said:

I agree not everyone wants (or needs)a goto setup.I enjoy my 200p skyliner. Worth every penny.IMHO. 

Yes I think I will be selling my big 250 dob with Goto, with the money perhaps buy a 4" frac to go onto the AZ GTi mount and go back to a manual 200p skyliner. Then I've got everything for home or trips away.

[Alan White]

Sometimes Phillip you don’t realise how well you and a scope work together until it has gone.

I have had two 150p f5 Newtonian, loved them both, observed loads, but sold them on each time for bigger, observed less each time after they have been sold, the ease of set up for the many shorter sessions and the comfort of sitting alongside a Alt Az mounted Newtonian is what made them the Goldilocks scope.

 

[A McEwan]

Glad that the Mak is working out for you! I've had a few - they perform very well.

Why do you wish to add a 4" refractor as well? The views will be pretty similar - unless it's the faster f5 refractor for wide-field views? 

Personally I miss my 8" f6 Dob too. It's a very good contender for "All-round-scope" of the century.

Ant

[KingNothing13]

So many twists and turns in this thread! 

As many have said other places, uses what works best for you!

I love my Apertura (GSO) AD10 - I have setting circles on the base, and inclinometer (going to use the level app on iPhone see if it works better) and SkySafari.

I do have a feeling that my next scope (Probably a larger Dob, down the road) will have goto - or at least built in digital circles.

[-philip-]

36 minutes ago, A McEwan said:

Glad that the Mak is working out for you! I've had a few - they perform very well.

Why do you wish to add a 4" refractor as well? The views will be pretty similar - unless it's the faster f5 refractor for wide-field views? 

Personally I miss my 8" f6 Dob too. It's a very good contender for "All-round-scope" of the century.

Ant

I was thinking of the refractor for more DSOs and the wider field, for when not just looking at planets. 

I am impressed with the Mak, I am not sure what I was expecting, but the detail I saw on Jupiter last night was better than I've ever seen through my 200 or 250 dob. I'm looking forward to taking it away on a few trips and may pop to Exmouth Beach at the weekend if there's clear skies. It really provides a bit of freedom that I've always wanted, but never had with my Dobs. 

Twists and turns is right! I change my mind and back again multiple times per day about what to do with my current Dob.. That I've really missed my old 200p manual dob a lot is telling me to get it back.. I know the 250 with all the Goto is a cracking telescope, I've just not got on too well with it..

 

[A McEwan]

Personally, I've owned scopes that I knew were good, but which I just didn't enjoy setting up and using. The Skywatcher GoTo 12" Dob was one of them. It was just such a struggle, even though the views were excellent. I sold it after a few months. If you have to think hard before setting it up every time, it's not worth hanging onto. Convert it into something you'll actually enjoy.

Maksutovs are excellent planetary scopes. Notwithstanding, I'd expect an 8" Newtonian to give superior views. If collimated properly and cooled down, of course.

Sounds like you're having fun though!  

 

[Dragon_Astro]

On 11/08/2019 at 10:09, -philip- said:

The 127 I've bought (pick it up on Monday) is really for camping trips, also I have a cottage booked in Pembrokeshire in October so wanted something to take with me, I can't take my Dob and the dogs in the boot..

Pembrokeshire hey, that’s where I am 😁where abouts have you booked the cottage?

[-philip-]

On ‎13‎/‎08‎/‎2019 at 21:21, Dragon_Astro said:

Pembrokeshire hey, that’s where I am 😁where abouts have you booked the cottage?

A little place called Castlemorris which is about 5 miles from Haverfordwest.

[Dragon_Astro]

12 hours ago, -philip- said:

A little place called Castlemorris which is about 5 miles from Haverfordwest.

Aah nice!

Im from Haverfordwest 😁👍🏻