Taking the plunge - Getting a Dob... (question about focuser)

[Rob_UK_SE]

Hello folks,

I have been an avid fan of SCTs for some time and also have an APO refractor. However, due to the changeable weather I have decided that SCT setups just don't suit my changeable local weather. I am loosing precious observing time due to the ever extending setup time (too many upgrades, piggy back bits ,etc).

Therefore, I have sold the SCT and intend to go for a dob - probably a 10 or 12 as it still needs to fit in our standard size hatchback car. A quality refractor and a dob surely makes a good pairing.

My question is, however, about the focusers on Skywatcher dobs. Do they have compression rings to secure the eyepiece (2" size), or a grub screw style system that leaves lovely marks all over your precious glass. I have built up my current eyepieces to achieve a set suitable for life (I hope) and really don't want to tarnish the barrels with the wrong type of focuser.

If anyone is able to shed any light on this I would be most grateful?

Thanks.

Rob

[WayBig]

My flex tube has grub screws,

[swamp thing]

Hi Rob

I wouldn't let it put you off, I would just budget to immediately change the focuser.

A nice moonlite would really make the scope so much better.

You don't need to tighten the screws up much anyway with a Dob as they cannot get into a position where they can fall out.

[Mike73]

Hi Rob

I wouldn't let it put you off, I would just budget to immediately change the focuser.

A nice moonlite would really make the scope so much better.

You don't need to tighten the screws up much anyway with a Dob as they cannot get into a position where they can fall out.

Great advice and was the first upgrade I did to mine, not cheap but it was worth every penny!

[Rob_UK_SE]

Thanks for confirming Chris. I suspected this might be the case.

Don't worry Steve, I'm not put off yet - it was, in fact, your 16" that got me thinking about moving towards a dob anyway!

After some reading it looks like the general view is that Skywatcher's Skyliner has a slight edge over Meade's Lightbridge (10 & 12) out of the box - hope this is the correct view?

I will indeed upgrade to focuser. What are the odds of the screws mounting into the same holes if I ordered a MoonLite CR1?

Any other upgrades I should be considering?

Regards,

Rob

[swamp thing]

Moonlite do a mounting kit so it bolts straight on to the Skywatcher.

Check it out:

http://www.firstlightoptics.com/moonlite-focusers/moonlite-installation-kit-for-newtonian-focusers.html

Jobs a good un as they say.

it was, in fact, your 16" that got me thinking about moving towards a dob anyway!

Oops! Sorry about that.

[scarp15]

Hi, I have just fitted a Moonlite CR1 to my 300p flextube, and as Steve and Mike have already confirmed, with the installation kit, it will be straight forward to fit, and the spacers will help with achieving focus.

[Rob_UK_SE]

Well, I picked up a 10" Skywatcher 250px today. Hooray!

Assembly was very straightforward, although it looks like I am going to have to wait for some slightly better weather if I want to attempt culmination.

The stock focuser sadly does indeed have the grub screws to lock. However, as both the 2" and 1.25" focus adapters are really focus extender types, I have ordered a 2" 50mm entender tube with a brass compression ring as a short term solution - after emailing FLO I was told the Moonlight focus is a 3-4 week wait .

Being slightly Mod obsessed I am wondering whether anyone has any tips for making the right ascension axis a little smoother? I appreciate that friction is rather important to keep the dob in place, however, it is fairly sticky at the moment - even with the screw pretty loose holding the two base plates together.

Regards,

Rob

[sgazer]

RA? Do you mean Az? My 250px was a bit rough in az, they rotate on 3 teflon pads IIRC, mine were a bit worn. I did change to castor rollers, but that was too smooth meaning it would roll back slightly after finding something. Maybe try some grease on the underside of the base where it slides on the pads. You want to retain some friction so it stays put when you want it to. On the ALT axis, you can tension it with the big knobs. But the scope is not balanced due to the focuser, so some balancing weight on the under side helps.