My experience with 'triangular stars' on GSO 12" RC

[Logieberra (Logan)]

Guys, on the AltairAstro website I came across what looks to be the new 'all CNC cell' referred to by GSO in their email. These might be for the 14" or 16" RCs. Hard to say. Even so, they look the same as the schematics for the 12" that I attached above. Cheers.

[Jussi]

Hi,

This threat seems very interesting, so I decided to join here.

I have 12" model with carbon tube. I decided to send it to Gemini telescopes in Italy. There it will get Integra85 rotator/focuser attached directly on the scope. Also a secondary and primary dew heaters get installed at the same time. Also they check that does it need any other enhancements.

I have noticed that my scope had a bit triangular star shapes sometimes like in this picture M51 in 2014 http://frostlandobservatory.galleria....jpg/_full.jpg

I haven't touched the collimation in a year and I think this one of the best images with my scope, considering star shapes http://frostlandobservatory.galleria....jpg/_full.jpg

Here are rest of the images taken with the scope http://frostlandobservatory.galleria.../2014+Deepsky/


Im going to keep this scope a long time. In future I hope I buy a camera with bigger sensor, perhaps a AO -unit.

Now it would be nice to have some advices what things I should ask them to fix? Of course they are professionals and see whats going on, but still some conversation is welcome. The scope already left with the courier and is going to be on its way a month or two, so there is time to plan things out.

[Logieberra (Logan)]

Jussi, welcome from Finland!

I refer you to this post, here: http://stargazerslounge.com/topic/18...ssambly/page-6

Member, 'RobH' sent his 12" RC to Astromeca in France. They made a number of changes to his RC, including new mirror cell, centering of secondary mirror and removal of mirror clips etc. As you are in Europe, and as the scope is now on its way to Gemini Telescopes in Italy, Gemini may wish to contact Astromeca to discuss their expert findings, compare notes and arrive at a solution for you? Otherwise, you may wish to contact Astromeca direct, to discuss. Just and idea.

Please also see my post, above. GSO (the manufacturer of these scopes) has designed a new mirror cell for the 12" RC. I suggest that you contact your RC telescope supplier and make enquiries. They may be able to source the new cell for you from GSO.

Personally, I would hold out for GSO's new mirror cell before doing anything too extreme in modifying your scope - as your images are that good! If you insist that changes be made, get them to upgrade the mirror cell by making it thicker and including more mirror supports. You may wish to look at RCOS/CDKs for inspiration.

Also, do you have a picture of the back end of your scope where the focuser connects? A valued member on this forum (Paul Haese) designed a new tip/tilt focuser plate for these scope and GSO now includes that part on all GSO 12" RCs sold in Australia. Ensure that you have that part on yours. You also refer to 'carbon tube'. Do you have the latest CF truss version?

I hope this translates well.

Regards, Logan.

[Jussi]

Hi and thanks Logieberra!

My imaging setup is here, minus the rotator http://frostlandobservatory.galleria...maging+system/

Gemini`s man thinked that the mirror cell is not the problem, but the direct attachment of the focuser.

At first I contacted to Astromeca, but they were too lazy to answer and I did not get good feeling about them.

I`ll try to ask from Telescope service and GSO about the new cell.

I`ll answer more properly when I'm out of work.

[clive milne]

There it will get Integra85 rotator/focuser attached directly on the scope.

Hey Jussi,
How much is the Integra 85 worth?

Regards,
c

[Logieberra (Logan)]

Originally Posted by clive milne

... How much is the Integra 85 worth?

I was wondering the same thing: https://youtu.be/OXrxtI5IpLM
Reminds me of Optec's new offering, the Gemini: http://www.optecinc.com/astronomy/ca...mini/index.htm

[Logieberra (Logan)]

Originally Posted by Jussi

... Gemini`s man thinked that the mirror cell is not the problem, but the direct attachment of the focuser ... I`ll try to ask from Telescope service and GSO about the new cell...

Jussi, see here. http://www.iceinspace.com.au/forum/s...d.php?t=117425 You have the old RC 12" design. Paul Haese, changed his solid tube 12" RC to CF truss. You may wish to discuss privately with Paul/TS Germany and look at doing the same (use the Private Message button). Paul is the expert on these scopes here in Australia. Importantly, your scope does not include the focuser tip/tilt upgrade that Paul designed. It solves your 'direct attachment to focuser' issue. See attached.

[Jussi]

Originally Posted by Logieberra

I was wondering the same thing: https://youtu.be/OXrxtI5IpLM
Reminds me of Optec's new offering, the Gemini: http://www.optecinc.com/astronomy/ca...mini/index.htm

Hi,

It`s 1800 euros, postages and suitable adapters included. It uses Seletek Armadillo 2 controller and its included to the price too. Seems good deal and the guy who made that Youtube video said that it has worked very nicely.

[Jussi]

Hi,

I got answer from dealer: Upgraded mirrorcell only fits for truss-version of the scope. GSO never answered.

The scope will reach its destination tomorrow and work will begin. Gemini`s guy Andras will evaluate the mirrorcell and need of rework.

[Logieberra (Logan)]

Hi guys. This YouTuber has followed my Velcro steps above on his older style 12" RC solid tube. Worth a look. https://youtu.be/0Qb1uP_NWzI. For what it's worth, I've never again seen the triangular stars on my scope after the mod.

[Atmos (Colin)]

Looks like it is performing beautifully

[ZeroID (Brent)]

+1 for the Velcro pads mod.
I'm not an RC user but I've built two 10" f5 newts, one 8" f8 and used velcro strips to give a pseudo 6 point support to the mirrors. No lateral movement, no pinching and will hold the mirror even if upside down. The system gives no stress as stated earlier and allows a wee bit of 'give' without losing collimation or introducing any distortion. A careful poke with a thin blade will release the velcro for any maintenance although I just wash the mirror in place if required. ( Second build is a Serrurier truss design )