Celestron Omni XLT 102 ED - Focuser Upgrade

[AdeKing]

I picked up a new to me Celestron Omni XLT 102ED a little while ago and was offered a Moonlite to go with it.  Much as I would have loved it, the funds wouldn't stretched that far and I turned down the opportunity, much to my regret.

The single speed Crayford on the scope is fine, but I really miss the fine focus facility that I'm used to on my ST102, WO ZS66 and Starwave 102 Fracs, so am looking to upgrade.

First and foremost, I am visual only and have absolutely no desire to delve into the dark arts of imaging.

I have a Lacerta fine focus attachment that I removed from a 6" Newt focuser.  This would fit the Celestron focuser, but the action is quite tight and I'm not convinced that I'd manage to re-adjust to the same level of smoothness on the single speed focuser as has been achieved by the previous owner(s) if I chose to revert to single speed.

So I'm considering the following choices.

1) Moonlite CR2 - The most expensive of the three options (https://www.firstlightoptics.com/moonlite-focusers/moonlite-cf-crayford-focuser-for-refractors.html).

2) Baader Diamond Steeltrack RT (https://www.firstlightoptics.com/baader-diamond-steeltrack-focusers/baader-steeltrack-diamond-rt-for-refractors.html)

3) TS Optics 2.5" R&P Focuser (https://www.teleskop-express.de/shop/product_info.php/info/p5769_TS-Optics-2-5--Rack-and-Pinion-Focuser---holds-Acc--up-to-6-kg---travel-95-mm.html)

4) TS Optics 2" Monorail Focuser (https://www.teleskop-express.de/shop/product_info.php/info/p3945_MONORAIL-2--Refractor-focuser---e-g--for-Skywatcher-96mm-flange.html)

These are in order of price, not preference.  My head is currently telling me to go for either the Steeltrack or the TS R&P, but I can't decide.

The ED100 is intended to be a forever scope for me, so I think it deserves a nice focuser.  

Are the Moonlites worth the extra cash over the Steeltrack? 

I've read comments about the Moonlites becoming slightly rough as the bearings wear through the anodising on the top of the drawtube, and that the Steeltrack has addressed this with two steel tracks under the bearings.  Are these grumbles justified and something I should be concerned about, or are they just a case of people picking holes?

In terms of load, I won't be hanging a DSLR or CCD off of this, neither will I be using many heavy 2" eyepieces with it at the moment.  My only 2" eyepiece is a 32mm Panaview.  However, I do often combine a 2" Lacerta Herschel Wedge with WO Binoviewers for solar observing and often use the binoviewers for Lunar, so I would like to minimise the chances of slippage with those two items.

I'm not in a massive hurry to get this, but am keen to hear any feedback on the above focusers, or suggestions of others, though I'll state here that a Feathertouch is strictly in the realms of fantasy.  Budget is £300 - 350 new though I'm happy to buy used as well.

Thanks in advance,

Ade

[Knighty2112]

A cheaper option might be to get a non rotating focuser. You could do the course focusing with the main focuser on your scope, then do the fine focusing with the non rating focuser. These just fit in your diagonal and then you fit the EP in. Been considering getting one myself.

[AdeKing]

48 minutes ago, Knighty2112 said:

A cheaper option might be to get a non rotating focuser. You could do the course focusing with the main focuser on your scope, then do the fine focusing with the non rating focuser. These just fit in your diagonal and then you fit the EP in. Been considering getting one myself.

Thanks Gus,

I hadn't really thought of that.  

I take it that you mean something like this (https://www.365astronomy.com/2-Non-rotating-Helical-Micro-Focuser-with-M48-thread-and-0.1mm-Scale.html?gclid=EAIaIQobChMIn_ulxd2r3AIVBTbTCh35EQNuEAQYAyABEgIfafD_BwE)

I did sort of try this with a WO erecting prism diagonal with helical focuser (https://www.firstlightoptics.com/diagonals/william-optics-125-90-degree-erecting-prism.html), but I just can't get on with the diagonal, it doesn't seem to deliver that same quality of views that I get from my WO mirror diagonal or my Tak Prism diagonal, despite the good press that this particular item seems to get.

The WO is a pain as I use winged eyecups and the WO helical focuser of course rotate's the eyepiece, so a non rotating one might be a good idea.  Thanks for providing food for thought.

Ade

[Knighty2112]

Yes. I have a Baader t thread focuser that does a similar thing, except it rotates the EP as you turn it.

[AdeKing]

24 minutes ago, Knighty2112 said:

Yes. I have a Baader t thread focuser that does a similar thing, except it rotates the EP as you turn it.

Just re-read my post and thats what i meant, the helical focuser on the WO diagonal rotates the eyepiece which drives me potty when using winged eyeguards.

[Knighty2112]

1 minute ago, AdeKing said:

Just re-read my post and thats what i meant, the helical focuser on the WO diagonal rotates the eyepiece which drives me potty when using winged eyeguards.

Yeah, drives me potty too. That’s why at some stage I want the non rotating kind!  

[Saganite]

Hi Ady,

I am pleased you are loving the scope, but then it is a beauty. The red Moonlite CR2 to which you referred was excellent on that scope, and I would recommend that route. I have something akin to the  steeltrack on my Dob , and I would prefer the Moonlite over that anytime, as I just don't get that silky smooth feel that you do with a Moonlite. I must emphasize that this is just my opinion, but that is how I feel.

Since I have been using my replacement 4 incher, the Tak 100, I have come to really love the rack and pinion focuser; only ever used mass produced scopes with R&P, and all were a bit crude.

I have just fitted a micro focuser to it , because ,like you, I want those subtle adjustments that a fine focuser gives, and honestly , I doubt I would go back to a Crayford, if I could avoid it.

For me the TS R&P  would need serious consideration.

Probably not helping Ady,  but perhaps, if this is to be a lifetime scope, take your time.

Incidentally, I never adjusted that silky smooth single speed focuser, and I am 99% certain that Chris never touched it either, it is factory set, and good....isn't it ? 

[AdeKing]

On 19/07/2018 at 21:06, Saganite said:

Probably not helping Ady,  but perhaps, if this is to be a lifetime scope, take your time.

Thanks for the information @Saganite and apologies for the late reply but I neglected to tick the notify me of replies button, D'Oh!

It is a cracking scope and has pretty much replaced my ST102, which was previously my most used OTA.

I have to confess that a red Moonlite is beckoning though as I said before I'm not in a massive rush to drop a large amount of cash on a focuser so soon.

I need to do a bit more research on the TS R&P focusers, there don't seem to be many reviews out there and I need to research how I would need to attach them to the OTA, I'm not even sure that their diameter is compatible with the XLT tube, but just thinking out loud.

I'm hoping to get a look and possibly a go with a Moonlite at the SGL Star Party at Lucksall, so I can wait for a bit longer at least, though if a 2" one pops up used, I might just jump right in .

I'm glad that you're enjoying the XLTs replacement, though it would have been a sad day if you were pining after the XLT after getting a Tak, but stranger things have happened.

The XLT is certainly going nowhere as far as I'm concerned.

Ade

 

[Saganite]

1 hour ago, AdeKing said:

Thanks for the information @Saganite and apologies for the late reply but I neglected to tick the notify me of replies button, D'Oh!

It is a cracking scope and has pretty much replaced my ST102, which was previously my most used OTA.

I have to confess that a red Moonlite is beckoning though as I said before I'm not in a massive rush to drop a large amount of cash on a focuser so soon.

I need to do a bit more research on the TS R&P focusers, there don't seem to be many reviews out there and I need to research how I would need to attach them to the OTA, I'm not even sure that their diameter is compatible with the XLT tube, but just thinking out loud.

I'm hoping to get a look and possibly a go with a Moonlite at the SGL Star Party at Lucksall, so I can wait for a bit longer at least, though if a 2" one pops up used, I might just jump right in .

I'm glad that you're enjoying the XLTs replacement, though it would have been a sad day if you were pining after the XLT after getting a Tak, but stranger things have happened.

The XLT is certainly going nowhere as far as I'm concerned.

Ade

 

Hi Ady,

Just to reiterate what I said, I am really happy that you love the scope, and you have every reason to.

I have now sorted out the use of my binoviewers on the FC100  to my complete satisfaction, and to that end I feel that I have every base covered. The three scopes that I now have are pretty much my hearts desire and allow me to  choose how ,when, and where to observe in the knowledge that optically I will not be left wanting, whether it be at home or travelling.

Just as a matter of interest, If I had to part with two of my scopes, the  Dob and the Tak would be gone in a heartbeat, and I would not pine, but the 5" f15, well that is a scope that I will never have to, because I will never part with it.