Solarmax 60 DS Focuser modification

[sabre414]

Hi all

I need some advice regarding a planned Coronado Solarmax 60 DS modification. Like so many of us who own a Coronado, I do not like the helical focuser that ships with this scope. It is particularly inferior when it comes to accurate focussing for imaging. I have had a Moonlite focuser shipped to me in the UK from Ron Newman at Moonlite. This focuser has a 2.5" drawtube which Ron has said is required for this type of scope to prevent the drawtube from hitting what appears to be an internal ERF. (See images attached for reference).

I bought this scope from Optcorp in Oceanside, CA, when on vacation in 2007. It was branded as a Solarmax 60 DS. So it has a tuneable double stack system at the objective, that came with a BF10. When I ordered the Moonlite focuser, I ordered the Solarmax 60 flange, which on arrival, I attempted to fit to the scope. It fits real well. However, having never opened up the scope before, that is, unscrewed the helical focuser from the scope, I found that there was an internal filter module (about 2 inches in diameter), attached to the now removed helical focuser. I think this is an ERF which obviously needs to transfer to the new Moonlite focuser. I believe I may have foolishly identified the wrong flange for the scope when ordering, but this was based on that fact that it is one of the 'original' Solarmax 60 DS scopes (or as was, Maxscope), my scope does not have the Richview focusing tuning lever. Ron seems to be of that opinion too, and is currently investigating if the flange should be replaced. I can commend Ron here for being very helpful.

I would be grateful for any advice regarding this issue, especially if you too have undergone a similar upgrade. Ron suspects that my scope was a kind of interim model between the Maxscope 60 and Solarmax 60. I must say that I am very pleased with the quality of the Moonlite focuser and really want to get this attached to my scope soon. I have attached images of the scope in various states to illustrate the problem I have.

Looking forward to comment and advice. Thanks in advance for the help.


Steven

[swisswalter]

Hi Steven

I see your needs, but sorry, I have no help, only fooling around with LUNT gears

[etatsolarchat]

what I see in the picture is the etalon, you need to remove just the focuser at the point just below the coronado sticker is my guess. if the moonlite was made to connect to the black ring then its the wrong place.

I saw on the web pictures of a finished moonlite/ds60 so you should search for them.

let us know how it goes

[hunterknox]

I'll be interested to see how this pans out. My own Maxscope SM60 would probably benefit from a similar upgrade. Good luck getting it sorted.

[marktownley]

Hmmmm, interesting, and good to see what's inside these things.

That is indeed the internal etalon assembly. It consists of a front collimating lens (with what appears to be an Allen bolt dead centre - I would bet this could be used to fine tune this assembly), The etalon internal to this, then I would bet, if you looked up the focusser tube there would be another lens at the back of the etalon assembly to refocus the light.

This is the unit that you would need to remove and relocate your moonlight focuser onto the end of this. Will it unscrew from the tapered coronado stickered bit of the focuser?

The etalon assembly looks very similar to that used in an SM40, and for this reason I would not recommend undoing any of the lil' 1mm(?) allen studds around the periphery of the assembly as these are used to locate the etalon with respect to the optical axis, mess with these and you will mess with the etalon tuning and could be difficult to return to an optimum.

My gut feeling at this stage is that if the etalon / collimating lens assembly cannot be removed from the focuser the moonlite is going to be a dead duck, sorry! I hope though i'm proved wrong.

[sabre414]

Hi Mark

Good to hear from you. In answer to your question regarding the internal etalon unscrewing from the helical focuser assembly, yes it does (see attached image). I also agree that it would be an act of folly to tamper with the Allen bolts on this assembly. I thought it would be a simple case of transferring the internal filter to that of the draw tube on the Moonlite, or to the flange that screws into the main tube assemby. I tried the drawtube and it was a tad too large to screw into it. so it looked like a flange issue.

Ron Newman from Moonlite, has been in touch with me via email and he has advised me that the internal filter should as thought, transfer from the helical focuser to the flange. The problem I have is that the flange I need is the one for the Solarmax 60 DS II (the scope with the newer Richview tuning lever). Moonlite have only recently manufactured this new flange for the Solarmax 60 DS II, and it wasn't on their website when I ordered the flange. Even though my scope has no Rich view tuning lever, Ron believes that the newer flange will do the job. He is also sending me a flange extender in order for the draw tube not to make contact with the internal filter when fully wound in.

I'm hoping that all goes well when the new parts arrive and that I can be rid of the helical focuser for good. There is a lot of slippage with the helical focuser and I have believed from day one of owning the telescope that it was a poor design option chosen by Coronado. I'll keep you all informed of progress.

[marktownley]

Ahhh, the etalon assembly is removeable, this means it will be do-able. The flange extender should sort it...

[sabre414]

All

As reported in an earlier posted message, I wanted to replace the helical focuser on my Solarmax 60 DS. I opted for the Moonlite CF focuser and corresponding attachment flange and extender. It was then a simple case of transferring the internal Etalon from the original Solarmax helical focuser module to the new Moonlite focuser, and attaching to the tube assembly. As you can see from the attached images, its a major improvement. I can't wait now for the next sunny day to get out and field test the new configuration.

Once again, my thanks go to Ron Newman at Moonlite for great advice and customer service.

Steve

[marktownley]

Oh yes! 8)

This is how all Coronados should be. I hope somebody important from the company is reading this, as, if a decent focuser was atleast an upgrade option, even if not stock with Coronado then i'm sure this would have a positive effect on sales. Cheap is not always cheerful.

I'm fairly certain that just about everyone who reads this will agree that the Coronado helical focuser is sub-par in the world of focusers...

:whistle:

[JohnW]

Just wondering how the Moonlite focuser went? Any testing done?? Could you give an update. Thanks.

[Merlin66]

Hmmm
Just found this thread....
Am I correct in assuming the central boss and screw in the front of the internal etalon is for "pressure tuning" the unit?? If so, how do you tune it in single stack mode????????

(I have an original SolarMax 60, s/n 600369 which just has the front external etalon. Since converted to to DS using another SM60 filter and mounted on an ED80)