Heading back to Visual Astronomy - A GOTO dob?

[davewaldo]

Well over night I've had 2nd thoughts. I'm just not convinced the SW is worth my hard earned cash. I still have my doubts to its long term performance, reliability and as a cash investment. Many people are happy while they are new, but there are starting to be several scopes now showing issues and pointing errors.

My option #2 has been to create a dob base for a 10" SW newt I already own and add argonavis. This would cost a total of $1000 or less and should have zero problems - ie, a base that will perform well long term, and good pointing accuracy. Although no tracking....

I'm in no rush so have plenty of time to decide.

Dave.

[Astro_Bot]

Ah, you suffer from visits of the "doubt monster" just like me. I'm one of those people who gets buyer's remorse for just thinking about it!

Originally Posted by davewaldo

I still have my doubts to its long term performance, reliability and as a cash investment. Many people are happy while they are new, but there are starting to be several scopes now showing issues and pointing errors.

I haven't really seen that. If you look hard enough online, you can find detractors for just about everything. Even more expensive mounts still need a service (AFAICS), although how one goes about servicing a GoTo dob, I don't know.

My option #2 has been to create a dob base for a 10" SW newt I already own and add argonavis

That does kinda change things. If you don't want/need tracking, that's probably a very economic option.

[Astro_Bot]

Just doing a bit of looking and it seems that 'official' Skywatcher dealers offer a 5 year warranty. Andrews is offering 6 years. That's not an extensive search, though.

[Osirisra (Ken)]

I own the SW 14" and in our group we have 2 10"s another 14" and a 8" all collapsible goto versions and everyone is quite happy with their scopes. Some have had to adjust the tension of the gears but that is easy quick tweak.

Accuracy is not really a problem and even with a rough alignment you can easily re-sync. The best thing is you use the goto completely, or not at all or bit of both, brilliant system that you can't find on many scopes. Really nice to be able to just push to the target and continue tracking, love it.

Great bang for buck scopes and you will not be disappointed.

For ease of use and quick deployment the 10" would might be the way to go as it a great size to not be a mission to move and or setup. with the 12'' and up you will need to disassemble the base as it is heavy and cumbersome for one person and this is a pain when viewing time is precocious. I'm still puting the base together for my 14" and the other guys with their 10" are all-ready up and running. Saying that it is worth the hassle ones you get to drag those photons onto that 14" primary.

Wish the 16" was out when I went to get mine.

[davewaldo]

Thanks guys! You're not making this decision easy!

One second I'm thinking low cost, build my own 10", next I'm back looking at the SW goto.... I'll ponder this one for a while. Maybe a 2nd hand unit will come up and that will make the decision for me

[mental4astro (Alexander)]

The third option is you find a second hand solid tube, 12" or 14", and make your own collapsible scope. Your own specks, your own unique style. I've often thought about purchasing the GSO 16" scope, ripping out the optics and other bits, and building my own instrument as I don't like the of build of those scopes, and can make my own to suit me. Same can be done to a solid tube instrument. Mind you, I make this hobby suit ME, not the other way around, .

[kustard (Simon)]

My own experience: I bought an Orion 14" goto (XX14g) which uses the Synscan controller. The optics are great but the controller (and mount drive) not so great and I had some issues with getting it serviced. In the end I've pulled out the drive and have reverted the scope back to a push-to using the Argo which works a treat.

An option is to get the Orion 14" non-goto (XX14i) like Rick got (http://www.iceinspace.com.au/41-651-0-0-1-0.html) and modify as required. You could even try an AstroDevices Nexus system on it.

*Note: It seems that Orion have updated their drive system on the scopes so maybe they have improved.

Cheers,
Simon

[davewaldo]

Hey Alex, yeah I have thought about building my own collapsible, but I figure I can stick with a solid tube for the time being if I decide to go down the ATM route.

Thanks Simon, for your report, thats exactly the thing I'm worried about with a SW goto, even if it is 3-5 years down the track....

Decisions Decisions....

Dave.

[mental4astro (Alexander)]

Just to stir the pot some more,

From this to this & this to transport the modification

From 90kg to about 30kg.

From a dog of a mount to a silky smooth joy.

[davewaldo]

Wow, what size dob is that? And do you have the plans available?

How does the pole system work, and does it take long to set up?

Cheers,

Dave.

[Shark Bait (Stu)]

Originally Posted by mental4astro

Just to stir the pot some more.... From a dog of a mount to a silky smooth joy.

Very nice rig Mental.

The stubbie cooler over the finder scope is a great idea that will be used on my setup from now on. Instant dew shield.

[el_draco (Rom)]

Originally Posted by davewaldo

Thanks Mark, yes but my problem (perceived problem) with the Skywatcher GOTO system is that the pointing accuracy will not be great, and its not known how robust/reliable this system is.

I didn't realise you could just push the scope around once set up though, does that not ruin the star alignment?

I remember in the good old days we used to "star hop" to a target. It was half the fun of the hobby because you just never knew what you would find. You could consider getting a decent right angle finder, say a stellavue 60mm -80mm and really do it simple....

[syousef]

I'm finding a digital inclinometer ($40) and manual azimuth setting circle plus a laptop do me fine. I usually get my object in or very near using a 42mm or 50mm 2" eyepiece. The azimtuth circle is a pain in the neck to print, but it can be done for the price of a few sheets of a4, a little printer ink and some laminate. I did end up cutting a small wedge out of the top circle on my dob base to accomodate though. I want some more regidity when I turn the azimuth circle during alignment, so 'm going to replace my circle with a laminate sheet I picked up from bunnings for $10.50.

Here's someone who's done it more neatly:
http://www.homebuiltastronomy.com/Ma...ingCircles.htm


I also have wheels on my base. Setup is a 1 star alignment. Total time to set up is about 5 mins from when I start carting my scope to the backyard.

I'm starting to work my way through the Messier list. Finding objects for the first time it takes me no time to be absolutely sure what I'm looking at. (I've had manual circles before on my smaller dobs but never locking wheels. I just bought a 12" and decided to do it properly).

Here is my alignment procedure.
1. Look up alt/az of alignment star
2. Plonk telescope down with azimuth roughly right and point at star (assisted by zero power finder, RACI)
3. Adjust telescope base to match az roughly and lock wheels
4. Fine tune by moving azimuth circle around and lock it down (my system uses velcro on the rim of the bottom ring to stick the laminated setting circle down in place)
5. Check and verify azimuth reading is correct.
6. Turn on inclinometer and point at alignment star. Zero inclinometer
7. Move telescope to negative altitude of star. Re-zero inclinometer
8. Move telescope back to star and verify inclinometer reading is correct.

This system is not accurate enough for extremely faint objects. I do sometimes have to scan a little. But not very much. Perfect for brighter messier objects.

[Astro_Bot]

Originally Posted by syousef

I'm finding a digital inclinometer ($40) and manual azimuth setting circle plus a laptop do me fine.

How precise is your inclinometer, if you don't mind me asking?

[davewaldo]

Originally Posted by syousef

I'm finding a digital inclinometer ($40) and manual azimuth setting circle plus a laptop do me fine. I usually get my object in or very near using a 42mm or 50mm 2" eyepiece. The azimtuth circle is a pain in the neck to print, but it can be done for the price of a few sheets of a4, a little printer ink and some laminate. I did end up cutting a small wedge out of the top circle on my dob base to accomodate though. I want some more regidity when I turn the azimuth circle during alignment, so 'm going to replace my circle with a laminate sheet I picked up from bunnings for $10.50.

Here's someone who's done it more neatly:
http://www.homebuiltastronomy.com/Ma...ingCircles.htm


I also have wheels on my base. Setup is a 1 star alignment. Total time to set up is about 5 mins from when I start carting my scope to the backyard.

I'm starting to work my way through the Messier list. Finding objects for the first time it takes me no time to be absolutely sure what I'm looking at. (I've had manual circles before on my smaller dobs but never locking wheels. I just bought a 12" and decided to do it properly).

Here is my alignment procedure.
1. Look up alt/az of alignment star
2. Plonk telescope down with azimuth roughly right and point at star (assisted by zero power finder, RACI)
3. Adjust telescope base to match az roughly and lock wheels
4. Fine tune by moving azimuth circle around and lock it down (my system uses velcro on the rim of the bottom ring to stick the laminated setting circle down in place)
5. Check and verify azimuth reading is correct.
6. Turn on inclinometer and point at alignment star. Zero inclinometer
7. Move telescope to negative altitude of star. Re-zero inclinometer
8. Move telescope back to star and verify inclinometer reading is correct.

This system is not accurate enough for extremely faint objects. I do sometimes have to scan a little. But not very much. Perfect for brighter messier objects.

Hi syousef,

Its a very good suggestion, however I've been down this road before, and built a system exactly like you describe. However I really got jack of it after a while and found it to be a fiddly and unstable system. I had a similar problem as you with faint objects and it leaves you wondering if you just can't see the object, or if you aren't pointing in the right place.

It is a great way to get get pointing on a limited budget and I did fine it very worthwhile, I just wouldn't go back there again, I'd just get and argo navis.

Cheers,

Dave.

[syousef]

Originally Posted by Astro_Bot

How precise is your inclinometer, if you don't mind me asking?

It reads in 0.1 degree increments. I'd probably trust it to 0.2 or 0.3. Subjectively I'm very happy with it. I've got a manual inclinometer, and I'd say that I can read that within 3 degrees or so.

The Wixey does have one fault. It's soft off switch still draws current and flattens your battery. I have to put a piece of paper between the battery and the plate to prevent contact when not in use. I bought myself a little switch to install so I don't have to open it up every time as that is a pain.

I don't doubt there are other inclinometers that don't have this problem.

[syousef]

Originally Posted by davewaldo

Hi syousef,
It is a great way to get get pointing on a limited budget and I did fine it very worthwhile, I just wouldn't go back there again, I'd just get and argo navis.

Fair enough. I'd probably buy an Argo Navis if money was no object, and if I weren't cheap ;-)

I think all dobs should come with manual setting circles though. Ridiculous in this day and age that we have to buy a basic model and fiddle with it to make it usable.

[Astro_Bot]

Thanks.

[mental4astro (Alexander)]

That's my 17.5". It was an original Coulter Optics Odyssey II. Part of the reason I named it Odessius.

Takes me 15min to set up. A bit longer if I add dew straps.

I did add encoders and an Argo which I fired up only once. I got rid of the lot the next day. I found my niche within astronomy, which is to relax and unwind. The electronics made it frantic and a race. But it all depends on what you want from astro, doesn't it. I prepare my session sometimes weeks before (part of my enjoyment too of astro), and end up with a list of six objects to sketch. I may only end up looking at 3 of them as a sketch can take upto three hours, and I'm happy . Like I said, it's not a race for me.

[Satchmo]

My perspective is a little different- I now put tracking ability above GOTO or setting circles, on my wish list. Having tracking is just like adding a few inches of aprture as you brain really has a chance to intergrate faint details.