Coronado SolarmaxII 60 problem

Use this section to discuss "standard" Baader/Coronado/ Lunt SolarView/ Daystar, etc… filters, cameras and scopes. No mods, just questions/ answers and reviews.
Post Reply
sonneyboy
The Sun?
The Sun?
Posts: 5
Joined: Sun Jul 01, 2018 4:52 pm

Coronado SolarmaxII 60 problem

Post by sonneyboy »

Hi,

I'm troubleshooting my Solarmax 60II which I purchased secondhand almost couple of years ago only just got chance to use it, however after a gloriously sunny day and only getting red in the face I simply couldn't tune it at all - having never used one of these before I assumed this was operator error but after the first three hours or so of tuning/focusing/tuning and so on I came to the realisation that it probably wasn't me to blame. Never once did the tuner lever offer any resistance whatsoever when turned in any direction and the image was always the same, even shifting the lever though a range of holes made no difference at all.

Long story short I opened up the tube and had a look at the Rich View tuner and found that the central rod that presses against the etalon was a very slack fit in the collimation glass hence the tuner applied no pressure, instead the pin had been pushed further into its mounting hole in the glass plate, with light finger pressure I could easily push the pin completely out of its hole. It looks to me like there may be something missing to hold this pin in place and I hoped somebody could advise if this is the case or if the pin IS actually just held by the glass and no other fixings. There were no loose or 'spare' parts anywhere.
IMAG0500.jpg
IMAG0500.jpg (1.1 MiB) Viewed 4260 times
IMAG0501.jpg
IMAG0501.jpg (1.05 MiB) Viewed 4260 times
(this is how it appeared in my scope, nothing has been removed by me)


Clearly what I had was not working so I made a temporary pin to replace the original metal/plastic one with a small flange to prevent it pushing though the glass plate hence applying pressure to the etalon when the tuner was operated to see if it made any difference.

With the tuner now doing something I could see a subtle change to the view when I operated the tuner, still hopelessly disappointing lack of any detail and difficult to see due to being quite dim. Investigating this new territory further I discovered my other issue is a badly rusted ITF filter. As I said, having never even looked through one of these scopes before I had no idea what to expect hence it took a while for me to get there. I'm going to order a replacement ITF from Beloptik but I still need to address the tuner pin issue properly.
IMAG0517.jpg
IMAG0517.jpg (814.22 KiB) Viewed 4260 times
So the mystery I need help with is what holds the pin in place in this tuner?
Many Thanks!


User avatar
Merlin66
Librarian
Librarian
Posts: 3970
Joined: Tue Dec 13, 2011 1:23 pm
Location: Junortoun, Australia
Has thanked: 173 times
Been thanked: 615 times
Contact:

Re: Coronado SolarmaxII 60 problem

Post by Merlin66 »

Maier Photonics supply a drop in replacement for the ITF.

I don't honestly know, I use an original SM60... but I'd think the central pressure screw is adjusted to give an on-band CWL (or really just to the red wing) and then given a spot of Loctite to hold it. Then by turning the turner ring the pressure increases on the etalon and the CWL moves towards the blue wing....


"Astronomical Spectroscopy - The Final Frontier" - to boldly go where few amateurs have gone before
https://groups.io/g/astronomicalspectroscopy  
http://astronomicalspectroscopy.com
"Astronomical Spectroscopy for Amateurs" and
"Imaging Sunlight - using a digital spectroheliograph" - Springer
sonneyboy
The Sun?
The Sun?
Posts: 5
Joined: Sun Jul 01, 2018 4:52 pm

Re: Coronado SolarmaxII 60 problem

Post by sonneyboy »

Hi Merlin66,

But my problem is the pin isn't firmly held by the collimation glass so the pin gets pushed through the hole in the collimation lens instead when the tuner is operated i.e pressed against the etalon. All my scope has inside is what you see in the pic - nothing else holding the pin in that glass surface other than goodwill.
Untitled.png
Untitled.png (2.06 MiB) Viewed 4240 times
I'm looking for any info regarding how this pin is firmly held in the collimation lens on other SM60II's or similar. I cannot believe there isn't something missing on mine to keep it rigidly held - a compression joint of some kind perhaps?

The closest pic I can find is on a post in this forum (viewtopic.php?f=4&t=24040&p=216323&hili ... ed#p216280) but the picture there only shows one side but it clearly shows there are parts that resemble washers etc which is more than just the metal pin poking through the glass which is all I have in mine. I'm guessing these are the parts which could have been removed by a previous owner but I cannot be sure. I'd love a closeup of both sides or even better a teardown photo/parts list from somebody else's stock SM60II.
sm40.png
sm40.png (467.6 KiB) Viewed 4240 times
Included below are some pics of my temporary tuner pin replacement which I used to allow me to actually test the tuner and determine my BF filter was rusted...
tempfix.jpg
tempfix.jpg (1.39 MiB) Viewed 4240 times
...as you can see I added a flare to my pin to prevent it being pushed through the collimation lens when the tuner is pressed against the etalon, this at least got me going but it has to be repaired better than this, ideally with parts resembling what should have been there to begin with (assuming there are any missing!)

Cheers!


User avatar
Merlin66
Librarian
Librarian
Posts: 3970
Joined: Tue Dec 13, 2011 1:23 pm
Location: Junortoun, Australia
Has thanked: 173 times
Been thanked: 615 times
Contact:

Re: Coronado SolarmaxII 60 problem

Post by Merlin66 »

Aahhh, OK, I now realise the problem!
I would have thought the retaining ring that the nylon tipped grub screw sits it would have been more robustly held in the glass plate....

I found these on my files...an early SM60 "failure" - looks like a small retaining collar?
Attachments
Optimized-solarmax60mm.JPG
Optimized-solarmax60mm.JPG (251.78 KiB) Viewed 4184 times
Optimized-solarmax60.JPG
Optimized-solarmax60.JPG (268.09 KiB) Viewed 4184 times


"Astronomical Spectroscopy - The Final Frontier" - to boldly go where few amateurs have gone before
https://groups.io/g/astronomicalspectroscopy  
http://astronomicalspectroscopy.com
"Astronomical Spectroscopy for Amateurs" and
"Imaging Sunlight - using a digital spectroheliograph" - Springer
sonneyboy
The Sun?
The Sun?
Posts: 5
Joined: Sun Jul 01, 2018 4:52 pm

Re: Coronado SolarmaxII 60 problem

Post by sonneyboy »

I agree about it looking like a retainer to an extent - it certainly would make sense if it was one. I've studied those pictures at high magnification and they gave me more questions than answers. Do you know if they are images from an SM60 as it would be from the factory?

When removed from the glass plate this small pin appears to be similar to a cap head screw with a tapped hole through its centre, the nylon tipped grub screw is screwed into the hole running though the cap head screw - basically a screw within a screw, I guess allowing for finer tuning at the factory. On your second picture I couldn't be certain if what looks like that narrow retaining collar isn't just the shoulders of the underside of the head of the 'outer' cap head screw because it looks like it could only be very small in diameter - that could only be a fraction larger (if at all) than the diameter of the screw head and the hole in the glass.

I'd dismissed it being a retainer because it wouldn't make a lot of sense for it to only be a smidgen larger than the drilled hole given the rear obstruction seems significantly larger it wouldn't be made that small out of optical necessity would it? The side we can see is the side that would do the most work in stopping the screw being forced through the glass. Perhaps if it had a washer between such a retainer and the glass to spread the stress loading away from the edges of the drilled hole I'd be convinced, otherwise i'd expect to see a crack just like that in that picture.

I'm curious to know what the larger obstruction is on the back side of the glass we can see in that picture and what function it performs. In other pics it looks like a washer as you can still see the head of the pin or maybe it just thickens the glass to provide more rigidity?

I have also considered that there might have been an insert (aluminium/plastic?) inserted through the hole in the glass into which the screw screws into from the rear through a washer. I've cobbled together this sketch of what I imagine this arrangement would look like based on the various pictures I've seen so far but its all theory, though it would explain the purpose for the external thread on the pin.
tuner_mod_PD_50.png
tuner_mod_PD_50.png (5.93 KiB) Viewed 4178 times

I found a pic (of yours!) from an sm90 and this has something much more like i'd have expected on the side facing the etalon assembly...
sm90 003.JPG
sm90 003.JPG (78.97 KiB) Viewed 4178 times

I found this other pic in an early review of the smII60 by Stephen Ramsden but it doesn't offer enough clarity to see what is on the back side of this glass.
smii60-ramsden.png
smii60-ramsden.png (375.4 KiB) Viewed 4178 times
http://www.stephenramsden.com/solarastr ... 2060mm.pdf

Any idea what temperatures these components are likely to reach when in use? This would have a bearing on anything I might have to fabricate to fix this in lieu of the original parts.

Do you know if there any service manuals for these scopes that might show an exploded view of these components?

Thanks for your help!


User avatar
Merlin66
Librarian
Librarian
Posts: 3970
Joined: Tue Dec 13, 2011 1:23 pm
Location: Junortoun, Australia
Has thanked: 173 times
Been thanked: 615 times
Contact:

Re: Coronado SolarmaxII 60 problem

Post by Merlin66 »

I think we need feedback from current SMII users.....


"Astronomical Spectroscopy - The Final Frontier" - to boldly go where few amateurs have gone before
https://groups.io/g/astronomicalspectroscopy  
http://astronomicalspectroscopy.com
"Astronomical Spectroscopy for Amateurs" and
"Imaging Sunlight - using a digital spectroheliograph" - Springer
sonneyboy
The Sun?
The Sun?
Posts: 5
Joined: Sun Jul 01, 2018 4:52 pm

Re: Coronado SolarmaxII 60 problem

Post by sonneyboy »

An update.

Firstly I still need some answers on the Etalon tuning pin which should improve tuning but at least this scope is now moving in the right direction.

I fitted the replacement ITF which arrived yesterday that I'd ordered from Beloptik. It took less than 5 days to ship from Germany to the UK. It was a straight replacement of the original ITF taking 5 mins to swap.

Eagerly I gave the scope a go - still using my crude wooden tuner pin inside the etalon housing. The image is very bright now (not too bright!) and the phrase 'night and day' comes to mind. It's much easier to find focus and way easier to get the eye relief right - it used to be hit and miss and quite frustrating due to the dimness.

After a little tuning I began to see subtle surface detail, having never seen any detail before through this scope (or any other h-alpha scope for that matter) this was very welcome and captivating. I could see proms and surface detail when I tuned back and forth. Using a 12mm EP it worked great - it's a full disk image presented to the eye and so it takes some concentration and perseverance to pick up on such small details but the longer I looked the easier it became to see them. I'm sure experience and time behind the ep will make this easier in future - and a blackout cover over my head would help keep my eyes accustomed to the view.

I hooked up my camera to see if I could capture something from this momentous occasion. I'm a complete amateur always learning on the fly so forgive the hopeless exposure settings and noise in the pics, i'll sure i'll get there eventually. I'm hopeful I can get better results, this was first light for this now 'working' setup.
detail.png
detail.png (503.23 KiB) Viewed 4112 times
prom.png
prom.png (633.21 KiB) Viewed 4112 times
(Camera is a dmk41au02)

Cheers!


Post Reply