How to strip and align a C11

[multiweb (Marc)]

Hi guys here's a couple of slides I did for the AIM at the ASNSW last night. I'll document some more as I go.

I think it will be of interest to any SCT owner as it shows photos of the guts of a C11 and explains how to improve the mechanical adjustments, and in turn the optical alignment.

This was a 2yr project on and off and is in no way recommended for a fully functional SCT but if you have soft focus with your SCT no matter what then it might be of help.

Any questions just shoot.
Thanks for looking.

PS: This should display and rescale on any device. PM me if any formatting issues. TIA.

[Barrykgerdes]

Great presentation Marc.

Barry

[RickS (Rick)]

That's a very useful resource. Thanks, Marc!

[multiweb (Marc)]

Thanks guys. Now waiting for some clear skies so I can do some pics.

[multiweb (Marc)]

Managed to get out last night and did some star test to tweak the mirrors. Shot some videos with the SONY NEX-5, a bit of Jupiter and shot a couple of 10s unguided on various bits in the sky.

This one is a stack of 3x10s on the sword. It's the full field uncropped. The picture will get better when I use the flattener but I wanted to see what the untouched field looked like. It's looking much better than before the mods. I never got it that clear at prime focus. Collimation is a tad out but good enough.

[Poita (Peter)]

I didn't know the Hotech did Hyperstar as well. Nice

[Poita (Peter)]

The stars on the left hand side of the sword image seem to have a little dot at about the 7 o'clock position on each star. Any idea what that is?

[multiweb (Marc)]

Originally Posted by Poita

I didn't know the Hotech did Hyperstar as well. Nice

Thanks - no, Starizona do the hyperstar. Hotech do the ACT. I just use the hyperstar in the centering process because it's convenient and I have one. That's all.

Originally Posted by Poita

The stars on the left hand side of the sword image seem to have a little dot at about the 7 o'clock position on each star. Any idea what that is?

Noise, field curvature, tracking error or any of the three. Could also be the cabling from the hyperstar. Heat plumes, etc... Some shots look better than others. I'll post more as I process them.

[Poita (Peter)]

Sorry, I meant I didn't know you could use the hotech to align the hyperstar. But now I see what you are doing

[TechnoViking (James)]

that was great!! ive always wanted to see the inner workings of the SCT, i was very intrested in the explination on collimation and image aligning. Is there an easy way to check the angle of the primary mirror without using the Ho_Tech equipment?

Cheers

James

[multiweb (Marc)]

Originally Posted by TechnoViking

that was great!! ive always wanted to see the inner workings of the SCT, i was very intrested in the explination on collimation and image aligning. Is there an easy way to check the angle of the primary mirror without using the Ho_Tech equipment?

Cheers

James

The Hotech kit makes it a lot easier. There is another way to check if the primary is square to the baffle tube with a laser at the back focus, a board at the front in the primary focal plane and a point light source (like an artificial star) in the middle of the board. It's a bit involved but it can tell you if something is off. I'll try to find a link to the procedure.