Changing Focuser for 12" dobsonian

[Richard Hather]

Hi everyone I'm thinking about changing focuser for my Skywatcher 12" dobsonian.

I only do visual work and I don't know which one is the best to buy I know the moolite focusers are meant to be good.

Also I wouldn't know were to begin when taking the old one off and putting the new one on I would hate to break my scope ?

Any advice or recommendations greatly appreciated thank you ? 

[Floater]

I installed a Moonlite as a replacement on my 6" Dob. I can't give any advice on which may be a better or worse replacement. But I'm happy and it was definitely a step up. Lovely focuser.

As for fitting, the Moonlite came with 'adapters' to fit various size scopes. Yours comes into the 'larger' size ? (relatively, I know), but I'm sure FLO would be happy to advise on any specifics.

p.s. I did have to file a bit on the OTA to fit the new focuser ... but please believe me when I tell you that DIY things are not my things! It was easy.

[Peter Drew]

If the replacement focuser is from the same manufacturer and intended for your model then the position of the screw holes will line up and it will be a direct fit. If however it is completely different then new holes may have to be drilled and even the aperture through the main tube might have to be enlargd. If you get stuck, bring it up to the Astronomy Centre and I'll do it for you.  

[Richard Hather]

Cheers guys I will drop FLO an email and take it from there ?

[Piero]

I also installed a Moonlite (CR2) on my Skywatcher 8" F6 dobson. It works very well in my opinion. As Gordon said, you will also need a Moonlite adapter for your telescope. FLO sell both. With my telescope I didn't have to drill the tube as the adapter already fitted the original holes. The installation was rather quick. It only required an Allen hex key if I remember correctly. 

It holds collimation pretty well. I checked this using my 2" Glatter's tools and there was no significant shift with any of my eyepieces. Movement is very smooth. 

 

[Richard Hather]

Thank you piero I will have a look at the adapter I really don't want to drill holes in my telescope and botch it up ?

[niallk]

Hi Richard, I have a Feather Touch on my 15", and just love it.  Rock solid with a heavy Paracorr + Powermate + Ethos load.

I've the Lacerta €80 dual speed upgrade on my 10" 250px. It is really great! But I only use my lighter 1.25" EPs in that scope.

Best of luck,

-Niall

[Piero]

This is the model I bought from FLO (50mm travel): 

https://www.firstlightoptics.com/moonlite-focusers/moonlite-cr-dual-rate-tri-knob-crayford-focuser-for-newtonians.html

And here is the adapter (in your case 12"): 

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

 

Moonlite also offers the focuser as single speed. At F4.9, I'd go with a dual speed though.  

[Richard Hather]

Cheers guys this really helps me a lot, I wasn't sure I wanted to change it but the Focuser isn't he best on my dob ?

[Ricochet]

If you do find you have to drill any holes in the tube remember to take the mirror(s) out first. You don't want small shards of metal being thrown against the surface at high speed. In a flex tube you would probably only need to remove the secondary and fit the cap to the lower section but in a solid tube i would remove both mirrors.

You might want to remove the secondary anyway so that you can check the squareness of the focuser prior to collimation.