Upgrade from an 8" newtonian

[FenlandPaul]

Hi everyone, I've been semi-actively lurking for some time trying to pick up tips and views on dobs, and could do with some expert views from the wealth of experienced folk on this forum.

I've recently got back into astronomy after a 14 year lull (which, ironically, was brought about by doing an astronomy degree - talk about killing the passion!). I have an old 220mm f/5 Beacon Hill equatorial Newtonian, which I picked up used when I was about 15 after LOTS of paper rounds and cleaning cars. It's done me well, but there are some significant flaws for how I'm able to observe nowadays:

-- the mount is a beast and rather clunky. It's really not what you'd call portable and whilst I enjoy the tracking I only get that when I'm at home because I don't have a power tank.

-- it's all a little tired, and it doesn't move smoothly etc. I'm not really handy enough to make a significant difference to this (my limit is spraying wd40 and hoping for the best).

-- the optics are not bad, but I've never had anything like a pinpr1ck star, especially at higher magnifications. And I have never seen the Great Red Spot, something which seems a little amiss given I've had the scope nearly 20 years! I've collimated it to the best of my ability (using good old AstroBaby - thanks for the tip off).

-- it really needs mounting on a plinth, probably about 2 feet high at least. My back usually starts to hurt after minimal observing time. In our current garden, a plinth or observatory isn't on the agenda.

So all this is making me itch to draw stumps and start over with a more modern scope. My main interest is in deep sky, but I also (who doesn't?) enjoy a bit of planetary. I'm visual only and don't see myself competing with the imaging chaps anytime soon. The requirements for my new scope are:

-- simplicity. Over complication will likely put me off going out.

-- Portable. I have a fairly dark garden in a small village, but my sky is quite obscured by my and neighbours' trees. So I occasionally take the scope in the car down to the local allotments, from which there's a stunning clear horizon for 270 degrees and it's away from stray light.

-- Aperture. Rather predictably I'd like more than the 8" I currently have. My initial enthusiasm had me looking at the various 16" dobs available, but my concern would be that size and set-up time would mean the scope gets fewer short-burst outings than it should.

-- Go-to??? Having grown up finding my way around and being, in equal parts, thrilled at finding something and disappointed at not doing so, I'm undecided on go-to. I love the idea of resorting to it, or making the most of a short session. I also like the idea of a drive, but that's probably just nervousness from not having used a dob before. Those of you who have owned manual and go-to dobs, to what extent do the drive motors etc add weight to the base and clumsiness to manual slewing?

How easy is it to pick up the knack of using and pushing / slewing a dob?

I have a decent shed for storage (with an extra wide door, specifically with a big dob in mind!)

The SkyWatcher range has really caught my eye, particularly the flextube range. Generally the feedback on the forums is terrific and they seem good value for money. Thoughts are tending to a 12" synscan or a 14" manual, but that kind of changes by the week! I plan to go to a few star parties to try to get a sense for some of the contenders too, if I can. Budget can be reasonably flexible, but I'd feel very nervous going above the £3k mark and would definitely prefer to spend something beginning with a 1.

I'd really appreciate any thoughts any of you very wise and experienced folk have on this.

Best and clear skies

Paul

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[Mr Spock]

If you are going visual only then a large dob with tracking would be ideal. Some dob users like to 'nudge' their way around the sky, but to me nothing is more relaxing than staring at an object for minutes with no interruptions. My mount has goto but I never use it

The most important thing is aperture. If you want faint fuzzies then the bigger the better.

[Daniel-K]

ive just sold my 14" Flexitube and they are great scopes, but they do weigh a fair amount. you can buy a tracking platform for dobs which is ideal but the nudging isn't a issue once you get use to your scope. a lot of people buy wider FOV EP'S so they don't have to nudge so much.if your going big get a 16"

[FenlandPaul]

ive just sold my 14" Flexitube and they are great scopes, but they do weigh a fair amount.

Was is a go-to, Daniel? Would you say the rockerbox of the 14" was manouverable by one person? Could I (a 6' 34 year old with average office-boy strength) lift it onto the tailgate of a Discovery?

Thanks

Paul

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[pete_l]

A couple of random (and strictly personal: other people - different opinions ) thoughts.

First, regarding GOTO: if you don't have an observatory, there is no such thing as "making the most of a short session" as the telescope takes longer to set up and align. Although the alignment can be eased considerably by having the positions of the tripod's feet marked on something permanent. Computerised setups also have an annoying habit of working fine on one night and then mysteriously not working the next - even if nothing has changed

Next: I have a 12 inch closed tube dob and it's at the limit of one-man portability. Even with this, I move the tube and the base separately. Maneuvering it through doorways and along garden paths in the dark is just too risky. (And heavy ... and bulky).

[jabeoo1]

Nudging the scope is fine, only more of a nuisance when others are using the scope and have not got the experience to do it themselves, so you are constantly readjusting the view.  When alone or in the hands of someone experienced its no problem at all.  

There is a lot to be said for avoiding goto.  I feel it would be at the expense of the pleasure of finding things out for yourself.  In its absence my knowledge of a small area of the the sky is richer without doubt.  My bagged list is pretty short, but I know where all of those objects are by memory,  manual dexterity, determination and at worse a glance at a star map.  I avoid anything that needs power and keep it simple.  Even with these rules I have known enough to go wrong with a viewing session !

The mirrors, collimation, cooling, planning and conditions are the most important things.  

With regard to size I find a 10" is my personal lifting limit (but thats a custom build and no doubt a bit heavier), which brings me on to say that I would be tempted to go for the best truss dob you can afford.  I would recommend looking into a custom build & keeping it below 2K.  You won't look back 

[FenlandPaul]

[quote name="jabeoo1" post="2405496" timestamp="1408872308"

With regard to size I find a 10" is my personal lifting limit (but thats a custom build and no doubt a bit heavier), which brings me on to say that I would be tempted to go for the best truss dob you can afford. I would recommend looking into a custom build & keeping it below 2K. You won't look back

Thanks Jabeoo1. There is something very attractive about pure manual and not having the help / hindrance of something requiring power.

I'd never thought about a custom build. Who are the main builders in the UK (or who built yours?)?

Paul

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[jabeoo1]

Thanks Jabeoo1. There is something very attractive about pure manual and not having the help / hindrance of something requiring power.

I'd never thought about a custom build. Who are the main builders in the UK (or who built yours?)?

Paul

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I will PM you !

[itmo]

Upgrade to 12" flextube goto if you can and if you can carry it. Thats what i did. it works with or without electricity quite fine. One problem though is the bulk. and whatever scope you get. get an observing chair.

[Dude_with_the_tube]

i have a skywatcher 350P goto or simpler to say 14" dob and i carry it in and out my self.Eat a lot of spinach and you will be able to do it too

also dont listen to that rubbish what others are saying about difficulty of setting up a Go-to dob on Alt-Az mount.Its a porky pies and is simple as chips.Same goes for EQ mount if you intend to use it only for visual.Astro photography requires very precise allignment,visual not really.Only one thing to remember.Apperture doesnt always rule.that is a wrong statement born in astro forums across the world and been proven wrong many times over.big dob is nice if you live in relatively non light polluted area.If you are in a middle of the city and dont intend to travel out to dark skies,dont bother with large aperture as that will be waste of your money.

[Daniel-K]

Was is a go-to, Daniel? Would you say the rockerbox of the 14" was manouverable by one person? Could I (a 6' 34 year old with average office-boy strength) lift it onto the tailgate of a Discovery?

Thanks

Paul

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the base is just more awkward than anything but yeah im 5ft 6 and I can lift the base in one go.  mines not the goto but heres some pics so you can see the size.

[Owmuchonomy]

Hi Paul

Thanks to this forum I have just acquired the SW300p Flextube Go-To. I have only tried it once due to weather and holiday constraints. I therefore apologise profusely to the more qualified 'Dob Mob' if I overstep the mark.

Here is my feedback:

Size: it is big! Can I lift it, yes I can but I wouldn't say it is comfortable to do so. The tube is easier to deal with than the base. I have skinned my shins already trying to lift the base through doors. Fortunately I have help on hand. I am quite fit from cycling but at 54 it can be a bit of a strain. The Goto doesn't add a lot of weight to an already bulky base.

Set up: remarkably easy. Just level the base, place the tube horizontal, point it north, switch on the Go-To and point at a bright star of your choice. Then I do a 2 star align. It takes a fraction of the time I normally reserve for my EQ set up. The 12" and above sizes have a proper needle roller plate bearing in the base so manual or Goto are very smooth. It found the appropriate targets. I have a lot of Synscan experience though so I know a few tricks.

Visual: I can only comment on using average EPs but I tried M57 and I was very happy with the view. I'm used to an SCT and a frac so coma is very apparent at the edges. I know I have to upgrade my EPs soon to cope with F5.

Power: the Goto takes 1.2amps so it's quite economical on your power supply. It was supplied with a simple wall transformer which works but I tend to use my observatory regulated 4amp supply as a precaution.

Collimating: I have delved into the dark arts. If you are used to this wizardry you'll be fine. It collimated after a while and seems to hold it during extension/compression of the trusses. Mine has been upgraded with better adjustment devices on the primary and secondary.

Any queries please ask.

Chris

[FenlandPaul]

I will PM you !

Hi James - thanks for the PM. Unfortunately I don't seem to be able to reply to them. The website you sent is very useful. I am frequently in Tewkesbury with my inlaws, so not too far away, and if I head towards the bespoke option then might take you up on your kind offer. Thanks for your time and info. Paul.

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[FenlandPaul]

the base is just more awkward than anything but yeah im 5ft 6 and I can lift the base in one go. mines not the goto but heres some pics so you can see the size.

Thanks Daniel. The pics are very helpful to judge size. The OTA definitely looks bulky, but then I imagine my 8" solid tube does too when I carry it, and it's definitely manageable.

I wonder what extra weight the goto adds to the base.

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[FenlandPaul]

Hi Paul

Thanks to this forum I have just acquired the SW300p Flextube Go-To. I have only tried it once due to weather and holiday constraints. I therefore apologise profusely to the more qualified 'Dob Mob' if I overstep the mark.

Any queries please ask.

Chris

I very much look forward to hearing how you progress with it, Chris. Thanks for the detail.

Paul

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[scarp15]

Here are a couple of pictures of the manual 300P flextube. I upgraded to this at the time from 8" of aperture. I was also a little hesitant concerning nudging, as my former C8 was on a tracking mount albeit quite rudimentary.

Never looked back, I have always enjoyed manually slewing a scope and love the freedom of movement, simplicity and light grasp on DSO's provided by dobsonians.  

[scarp15]

I ought to have added that the focuser on this was an addition, Moonlite CR1.

[FenlandPaul]

Thanks all of you for your thoughts. While I deliberate and procrastinate, I've splashed out on a pair of Revelation 20x80 bins in the TH sale to reacquaint myself with the Summer and autumn sky without the frustration that my current scope brings. I think I'll sell the scope shortly - hopefully to someone who will permanently mount it - and move from there. Paul

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[Ptarmigan]

some pics so you can see the size.

Pic #1, now that is what I call a selfie with feeling ! The energy, the bended knee, motion captured in a still-life, we look for a bead of perspiration on the brow , , heheee , , nice one

Im only 5'6 +a bit of imagination, but sadly a lot older and a back that I have to be careful of,

do you still have it, has it gone yet ?

can you put it on your bathroom scale please and tell us the kg (or lbs < I woz trying to be modern ) ??