Renamed - StellaLyra vs Ursa Major Dobsonian

[Guest]

2 hours ago, bosun21 said:

My 8” Stella Lyra Dobsonian holds its collimation pretty well as is. I have already fitted the bobs knobs screws on my secondary mirror and they are holding collimation pretty well also. I am thinking that it would be a good idea to upgrade the springs on my primary mirror and was wondering how long it took them to arrive from America?

I have seen guys on here order from him.  Seems like it is a couple weeks from Indiana to the UK.  I ordered a sweater from Ireland last November and it took three weeks, it has to be better now.....right?  He is actually only a couple two or three hours away from me.  

Edited April 16, 2022 by Guest

[bosun21]

1 minute ago, Mike Q said:

I have seen guys on here order from him.  Seems like it is a couple weeks from Indiana to the UK.  I ordered a sweater from Ireland last November and it took three weeks, it has to be better now.....right?

I wouldn’t bet on it. I will probably just measure them and buy the equivalent springs from a UK supplier.

[Guest]

His springs are stiffer and the wire is thicker.  They are a significant improvement over what came on my scope.  

[bosun21]

Yes I know that, but there will be the same springs on sale here. As long as they are the correct length and diameter the thicker gauge wire will provide the necessary tension required 

[Paul_Sussex]

Hopefully the last question I have - on a Crayford focuser, is there a standard position for the locking and tensioning screws? And is it the same way round for all makes? For instance, on the Ursa Major which is which? The downloaded instructions weren't that clear. (As in, didn't say anything 🙄)

Edited April 18, 2022 by Paul_Sussex

[bosun21]

The bottom is the focus lock and the top is the tension adjustment 

[Mr Spock]

On 16/04/2022 at 18:46, bosun21 said:

I am thinking that it would be a good idea to upgrade the springs on my primary mirror and was wondering how long it took them to arrive from America?

Mine only took about a week. 

[Paul_Sussex]

Shipping today!  🤩

[Dark Vader]

On 15/04/2022 at 11:04, Paul_Sussex said:

On a side note, one of the sites I may be using has (variable length) grass - a small green space just up the road. I've seen some people suggest a groundsheet/tarp to protect a Dobsonian mount, but I wondered whether a sacrificial ground board would work? Something cheap like MDF or OSB, cut slightly larger than the base with holes to take the feet. Could be painted or epoxied for additional protection. Has anyone done this before?

A lot of people, myself included, have used a water butt stand for a Dob. Just measure the diameter of the base and cut some holes to fit the feet with a Dremel. 

[FLO]

Regarding replacing GSO telescope collimation springs - we recommend you check if it is necessary before doing so.

Most conversations on the internet recommending stiffer springs are several years old and/or relate to an older (prior to Ursa Major and StellaLyra) secondhand telescope. So the advice is no longer relevant. 

The springs fitted to GSO manufactured telescopes sold today are not the same as those fitted to earlier models. 

HTH, 

Steve 

[cajen2]

Ah, I did wonder about that as the springs on my StellaLyra primary seem fine.....

[Chris]

I was worried about the springs when I decided to test the GSO / StellaLyra 6" F/4 imaging Newtonian, however I've been pleasantly surprised! In fact I've been imaging with the scope and I still haven't got round to collimating it despite it travelling from China to Exeter, then Exeter to Ipswich. Collimation isn't perfect yet and it does need a tweak, but this is the first time I've ever managed to get any kind of image out of an f/4! despite owning two f/4's prior to this one! 

I've not cracked the spacing for the coma corrector yet but I'm just pleased that the whirlpool galaxy looks like the whirlpool galaxy lol Looking through one of my previous f/4's was like being on an acid trip! 🤪

 

[Mr Spock]

Depends on the size - my 12" springs were weak and the scope wouldn't collimate without clunking and the mirror moving. Stronger springs fixed that. What doesn't help is the collimation bolts rubbing on the cell holes. Some sort of plastic sleeve would help here and perhaps even remove the need for stronger springs. Still, you have to remember how much the scopes cost when sizing up fancy details like that 

[Paul_Sussex]

34 minutes ago, Chris said:

I was worried about the springs when I decided to test the GSO / StellaLyra 6" F/4 imaging Newtonian, however I've been pleasantly surprised! In fact I've been imaging with the scope and I still haven't got round to collimating it despite it travelling from China to Exeter, then Exeter to Ipswich. Collimation isn't perfect yet and it does need a tweak, but this is the first time I've ever managed to get any kind of image out of an f/4! despite owning two f/4's prior to this one! 

I've not cracked the spacing for the coma corrector yet but I'm just pleased that the whirlpool galaxy looks like the whirlpool galaxy lol Looking through one of my previous f/4's was like being on an acid trip! 🤪

Chris - just hoping I can see something that clear with the 6" F/8. (Or was that AP?) And loving the Youtube channel as well!

Edited April 21, 2022 by Paul_Sussex

[Chris]

22 minutes ago, Mr Spock said:

Depends on the size - my 12" springs were weak and the scope wouldn't collimate without clunking and the mirror moving. Stronger springs fixed that. What doesn't help is the collimation bolts rubbing on the cell holes. Some sort of plastic sleeve would help here and perhaps even remove the need for stronger springs. Still, you have to remember how much the scopes cost when sizing up fancy details like that 

Fair point Michael, your 12" mirror is going to weigh a whole lot more than my tiddly 6".  

[Chris]

22 minutes ago, Paul_Sussex said:

Chris - just hoping I can see something that clear with the 6" F/8. (Or was that AP?) And loving the Youtube channel as well!

Hey Paul thanks! Well you'll definitely see the planets nice and clear with a 6" f/8, the f/8's are a real planet killer. The above was just a handful of 3 minute exposures stacked together, I'm not a hard core imager but Just like to tinker 🙂 

[Spile]

I would echo the caveat about checking if you need to replace springs and bolts before assuming you need to. My 8” Skywatcher 200P very rarely needs the secondary or primary adjusting so the Allen keys and Phillips screws are fine. The default springs are fine too. I don’t load my Dobsonian into my car very often so that could explain why I am fine with the default setup.

[Paul_Sussex]

Well, my early retirement present has arrived! So a weekend of struggling with mount building, finder alignment and hoping it's in collimation...

[wulfrun]

10 minutes ago, Paul_Sussex said:

Well, my early retirement present has arrived! So a weekend of struggling with mount building, finder alignment and hoping it's in collimation...

Have fun!

[Ratlet]

8 hours ago, Paul_Sussex said:

Well, my early retirement present has arrived! So a weekend of struggling with mount building, finder alignment and hoping it's in collimation...

Let us know in the thread how you get on.  Nothing worse than a thread where someone decides on the scope and then it just ends!

I'm keen to find out how you get on

[Paul_Sussex]

Well, yesterday was mostly...

Today is assembly and hopefully aligning the finder.

Unless something changes, no clear skies until Sunday night and no moon or planets in view, so I'll be mostly finding my way around the sky and looking for anything interesting. But yes...I'll update on progress, as and when.

[Paul_Sussex]

So...assembly completed and finder roughly aligned. There's nothing far enough away that I can get a clear sight on. Or maybe it's just me? Will have to go out in daylight tomorrow and find a good location to sort this out.

First impressions (bearing in mind this is my first ever telescope)

The base went together alright, once I'd worked out that the holes to attach the uprights weren't equidistant. My fault for not checking first. I was a little disappointed by the use of wood screws straight into composite board, but I guess that's to keep costs down. Once I mounted the OTA everything seems nice and smooth, although I'll have to check the tension on the azimuth movement. The tube itself seems nicely finished, in particular the CNC machined focuser, which is very smooth with no play and just under 5cm of travel.

Sitting on a swivel chair (interim measure) I found it fairly easy to look through the eyepiece at all elevations, but I will need to invest in a stool of some sort. The straight through finder I found more awkward, so that may have to be changed in the future.

The eyepieces are branded as Ursa Major, but I understand from FLO's site are GSO, which are supposed to be reasonable for starting with.

Not much to add. Now just waiting for some clear skies...😉

[cajen2]

37 minutes ago, Paul_Sussex said:

So...assembly completed and finder roughly aligned. There's nothing far enough away that I can get a clear sight on. Or maybe it's just me? Will have to go out in daylight tomorrow and find a good location to sort this out.

First impressions (bearing in mind this is my first ever telescope)

The base went together alright, once I'd worked out that the holes to attach the uprights weren't equidistant. My fault for not checking first. I was a little disappointed by the use of wood screws straight into composite board, but I guess that's to keep costs down. Once I mounted the OTA everything seems nice and smooth, although I'll have to check the tension on the azimuth movement. The tube itself seems nicely finished, in particular the CNC machined focuser, which is very smooth with no play and just under 5cm of travel.

Sitting on a swivel chair (interim measure) I found it fairly easy to look through the eyepiece at all elevations, but I will need to invest in a stool of some sort. The straight through finder I found more awkward, so that may have to be changed in the future.

The eyepieces are branded as Ursa Major, but I understand from FLO's site are GSO, which are supposed to be reasonable for starting with.

Not much to add. Now just waiting for some clear skies...😉

If you're as happy with your UM as I've been with my 8" SL, you'll be very contented. I' d definitely consider upgrading the finder to a RACI, though, unless you're a yoga expert.😉

Edited April 23, 2022 by cajen2

[Paul_Sussex]

So, first light with the Ursa Major.

Out last night with a clear sky. No moon or planets, so just panning around to see what I could see. I only reliably know Ursa Major, Cassiopea, Orion and Gemini and had only a small star chart with me. Orion was too low to get sight of M42 and I had a lot of trouble finding my way around the sky. I was pointed towards the galaxy "belt" and possibly spotted a few fuzzies, but nothing I could readily identify. The main excitement was giving up on that (starting to get a bit cold after eleven), panning around with the 9mm Plossl (I'd been using the 25mm up to now) and just by chance spotting and following what I hope was a double star somewhere around Leo. Don't know how to describe the distances, but through the eyepiece looked something like this...

So a slightly frustrating evening. Hasn't put me off, but some things to address.

Pros

Really like the UM150 - light, easy to move around.

Optics seemed very good to me. Some spikes apparent but not huge.

Had a good evening, with some helpful advice.

A great dark sky site - Kithurst Hill if anyone is in range of the South Downs.

Encouraged me to just get out in the garden more and start finding my way around the night sky.

Cons

I found the straight through finder almost unusable - not an equipment fault, due to age and fitness (or lack of). I'd have been lost if someone hadn't lent me a 9x50 90 degree finder.

The single speed focuser need very precise management. I was continuously over-focusing until I could hit on a sharp image.

Lost in the sky - although this is down to me.

At the moment, I am seriously considering whether (if possible) I should return and update to a StellaLyra 8", which comes with the finder and focuser and at 8" might be easier on my old eyes? I would say that none of the above is the telescope at fault. I think I have reasonable realistic expectations of what I can and can't see. I'm happy enough with the choice of a Dobsonian reflector. If I was twenty or thirty years younger I would be more than happy, but I just feel as if I'm handicapping myself from the start?

[JOC]

On 20/04/2022 at 23:26, Dark Vader said:

have used a water butt stand for a Dob

I tried one for my 8" Dob and found that my plastic water butt stand was way too flexible.  It needed filling with cement, but then I would never have shifted it.  

 

27 minutes ago, Paul_Sussex said:

I found the straight through finder almost unusable - not an equipment fault, due to age and fitness (or lack of). I'd have been lost if someone hadn't lent me a 9x50 90 degree finder.

Get a Y mounted dual finder mount (I found someone 3D printing them very reasonably on a popular auction site) and mount a 90 degree optical RACI next to a cheap as chips (often <£10) 2nd hand very basic red dot finder and you will find targets in < 15 seconds that you couldn't find in 20 minutes using an optical finder alone.