Skywatcher Quattro f4 Imaging Newtonian telescopes

[Tim]

BTW TJ, I have a TS alu. secondary support on the way to replace the GSO one. If you want I'll let you know how I get on. I'll be a good chance to set the offset, too. Also, does anyone know what to use to bond the secondary on?

That should be a lot better, the plastic one is rotten. I think I would be inclined to bond the mirror in the first instance with a good quality sticky pad in the centre, and if the position was 100% square then fix with some epoxy around the edges, enough to hold it, enough to allow it to crack off if needs be. Do take care to get the alignment right!

When you get a chance to do a star test, check for a turned down edge on the mirror, if the star has a hard bright edge one side of focus and a soft diffuse edge on the other, you likely have a mirror with this. You can paint (carefully) the edge of the mirror if so. The trouble with the budget Newts is that you spend so much and so long "fixing" them, that it would have been better to spend a bit more in the first instance. Good old hindsight

[Macavity]

Do you have any pics taken with the f/4, Chris?

Sadly, not as yet, Paul. Waited eagerly for the motor-focuser, and it seems to have rained solidly ever since.

The collimation still needs a tweak, and previously I'd mostly been juggling extension tubes and "testing" it visually - As a pseudo-Dobsonian on a Giro III. So many variables, I think I'll have to start taking notes - A notable first.

[Revs]

The trouble with the budget Newts is that you spend so much and so long "fixing" them, that it would have been better to spend a bit more in the first instance. Good old hindsight

In all honesty I knew there were issues with the GSO/TS newts and accepted that before buying. I'm quite enjoying tinkering with it and have learned a lot about newts in the process. The main thing was the optics and focuser had to be good, and both are excellent. I'm replacing the secondary support, which only leaves the poor primary cell. I'm still in two minds about replacing that as it is doing the job. I've had no mirror slipping problems as yet but the design is poor. The uprated ones do look rather nice

All in all the Quattro does look better value, provided the the optics are good (which they will be) and this new focuser is as good as it needs to be. My only real concern is the baffles, but we'll have to wait and see on that one. The CT version should look the biz and hopefully eliminate flex round the focuser.

[Tim]

Well, I plan to strip it down completely before using it in anger, and will faithfully report my findings I have a mental workflow idea, but I will hopefully get it down in writing and perhaps with pics too, if there's time.

(knowing me it will be clear the night it arrives and I will throw it on the mount as it comes )

[Revs]

Just happened across this pic of a 250/1000...

[Tim]

OVL are now saying early September

[Revs]

Bummer

This is the main reason I didn't want to wait. There was no way it was gonna be July. Hope they don't delay it further for ya TJ.

[Deneb]

Why does not suprise me ! Whats the Delay this time ? Buy yourself a GT81 Tim, it will keep you occupied for a while

Nadeem.

[MikeWilson]

OVL are now saying early September

Oh dear (!)

[ollypenrice]

What I found with the GSO800/F4 was that even if you got the optics collimated the tube itself distorted with CCD gear hung from the focuser. This destroyed orthogonality, obviously.

That's why the CF version is interesting. I have a CF racing bike and that is a stiff as a... well, let's not go there!

Olly

[Revs]

IMO the reason to get a budget f/4 newt is for use with a DSLR. If I had the cash to get a CCD, filters and filter wheel a newt would be well down my list of scopes. The shorter exposure times make it worth putting up with the inherent quirks, but for CCD imaging I'd go with a frac, or a high-end newt like a AG8, which is a no-compromise design with a price tag to match.

I am currently in the process of designing a bit of kit to strengthen the tube around the focuser so we'll see how that goes. Otherwise I think I've made the TS/GSO as good as it can be, with a few mods, tweaks and shims. Just need some clear skies and longer nights now..

[George]

OVL are now saying early September

Maybe just in time for Christmas then

[ollypenrice]

IMO the reason to get a budget f/4 newt is for use with a DSLR. If I had the cash to get a CCD, filters and filter wheel a newt would be well down my list of scopes. The shorter exposure times make it worth putting up with the inherent quirks, but for CCD imaging I'd go with a frac, or a high-end newt like a AG8, which is a no-compromise design with a price tag to match.

I am currently in the process of designing a bit of kit to strengthen the tube around the focuser so we'll see how that goes. Otherwise I think I've made the TS/GSO as good as it can be, with a few mods, tweaks and shims. Just need some clear skies and longer nights now..

Totally agree. Good point. I hope your mods work and I strongly suspect that they will.

I'm interested in the SW version though. I already have that FL so won't be in the market but I hope it works out.

Olly

[Earl]

OVL are now saying early September

Well taking the square root of the number of clear night between now and then and the date divided buy the suppliers Vat number.

2.5 Nights missed

[fatwoul]

Why does not suprise me ! Whats the Delay this time ? Buy yourself a GT81 Tim, it will keep you occupied for a while

Nadeem.

Dunno about Tim, but I'm thinking about it. Would quite like a widefield frac in time for Orion, etc. Still happy with yours?

[fatwoul]

...or a high-end newt like a AG8, which is a no-compromise design with a price tag to match...

If anybody has to justify an AG8 to a resistant wife, just gloss over the price and show them this picture (from the OO site):

"See, dear? It's a tiny scope. That's all I want."

[Deneb]

Dunno about Tim, but I'm thinking about it. Would quite like a widefield frac in time for Orion, etc. Still happy with yours?

I've actually grown to like it & it will be a keeper. The TRF2008 Reducer/Flattener works wonders with this scope, as you can see yourself from the images posted up recently. Producing nice & flat images..with pin point stars to the edge... I do wonder how much the GT81 will be marked up on the next batch though ! Also I do wish WO integrate that Red Backlight on the focuser readout otherwise the DDG digital readout is useless for for night time use.

Nadeem.

[James]

The 8" Quattro's have arrived in the UK and will be shipping shortly (within days).

The 10" Steel versions are due imminently but I'm afraid we're still awaiting confirmation of when the 10" Carbon fibre versions will be available. We'll post here as soon as we know.

James

[shaunster]

Do you only have enough for backorders or if I order now will I recieve it soon? (meaning not in 3 months )

8" CF model BTW

[James]

Unfortunately we've had it confirmed that the 10" Carbon Fibre versions are delayed and should be in the UK during the second week of September

Do you only have enough for backorders or if I order now will I recieve it soon? (meaning not in 3 months )

8" CF model BTW

We have enough for backorders and an additional quantity coming into FLO so orders should be delivered within 2-3 days

James

[Deneb]

Thats good news for the people who have ordered 8" versions. Hope all goes well for you chaps/girls...

Nadeem.

[MikeWilson]

Yay! Order placed for one of the 8" CF models.

Now time to sell my 6" F5 Newtonian

[Tim]

Even if they do arrive in mid-sept (believe that when I see it ) I will be away to Kelling for nearly three weeks, so its going to be a long time before I get to play with mine

Very keen to hear some reports about the 8" CF though guys, do post your observations!

[MikeWilson]

If anyone's interested and if time allows, I'm tempted to run a uStream/BlogTV unboxing/review of the scope.

[Tim]

Pics would be good Mike, specifically;

Focuser

Focuser mounting plate adjustment (if any)

Tube internally

Spider

Secondary mirror fixing

Primary mirror cell

Primary mirror

Star test (I plan to write a primer for star test pics at some point, but it isn't hard, quick method described below!)

Things it would be worth checking on your scope before you use it:

Position of secondary, it will likely be offset towards the tube wall opposite the focuser, but should be central to the focuser axis.

Position of centre dot on the primary. This must be dead centre of the mirror. Easy way to test is to lay mirror face down on paper, draw around it, cut out the circle, fold it into a quadrant, and cut a tiny piece off the centre, then overlay the paper on the mirror (you might need to iron it )

Usually the dot will be near the centre but not exactly central. EXTREME care is needed if you have to move it.

More difficult to check, but important is the squareness of the focuser to the tube. Good luck with that! I have a useful technique but it requires temporarily marking the centre of the secondary, which is a dark art in itself :s

If you can do these things before you even start to look at its collimation you will be better off. At f4 it is all about the detail!!

I wouldn't mind having a butchers' at your scope when it arrives, maybe we could get together.

For a star test, pick a reasonably bright star, but not Vega/Arcturus etc. The main constellation stars are quite useful, and choose one that is highish in the sky if you have the option.

Take a short exposure (1s maybe) of the star dead centre of the frame, and then at diametrically opposed corners, and maybe halfway between the points.

If you are using your QHY8 or 550D, it would be useful to see how the colours come through the coma corrector, so splitting each result frame into RGB channels, and measuring the star size in pixels compared to its central position would reveal this. (The star should be sharpest/smallest in the centre of the frame, assuming collimation is good and everything else is aligned properly. You might expect the stars to be a little larger away from centre, and possibly start to show the effects of coma toward the extreme corners. If the coma corrector is altering the focal point of any of the colours (RGB) then the star in that channel will appear larger due to be slightly off focus.

Usually with a OSC camera focus will be found on the green channel to which the camera is more sensitive. Red and blue are either side of green and usually the separation is greatest between those two colours, comparing the star in blue compared to red would be interesting, if you get time

The good thing with these tests is that they can be done on a part clear night, you only need a brief window.

Looking forward to your findings Mike!

Tim