RC 6 Collimation in Melbourne

[VPAstro]

Hi All,

Just wondering if anyone knows of a telescope repair shop in Melbourne that would be able to properly collimate an RC 6 telescope.
Maybe even someone on the forum can help me out if they have the tools.
I have spent a lot of time reading and watching youtube videos, but still can't seem to get it properly collimated. I have the focuser tilt plate and a farpoint collimation kit, but with these tools, can't accurately collimate the primary. Hoping someone can help out.
Many thanks
Andrew...

[Martin_S]

Andrew, have you seen the link to my post in Solarchat?

https://solarchatforum.com/viewtopic.php?f=10&t=28314

Martin

[Stonius]

How are you assessing your collimation?

[VPAstro]

Hi Markus.

Thanks for your reply.

Yes, I did see that post, and it looks very good, but I didn't have the equipment to do it. Maybe I need to buy a barrel type camera and cctv lens.

I am testing on an out of focus star which shows the central obstruction off centre. I can't seem to get it centered via the star test. My images show severe "coma" on the left and difficult to get focus. I am using an STT8300 with the 8pos filterwheel and guider, which is quite heavy, so I guess there is some tilt there as well.
This is one image, https://www.flickr.com/photos/185680942@N04/51108178052/in/dateposted-public/ which I was happy with, but they are now getting progressively worse, and if I have to do a meridian flip, I can't align the stars.

Thanks,
Andrew...

[Stonius]

Have you tried this method? http://www.deepskyinstruments.com/truerc/docs/DSI_Collimation_Procedure_Ver_1.0.p df


The problem with using the centre dot as reference is that the center of the mirror is not necessarily the center of the optical axis. The above method uses on and off-axis astigmatism to align the mirrors.


There is also https://www.ccdware.com/products/ccdinspector/index.html which will give you a 3D image of your focal plane and help you adjust it.


Best,


Markus

[VPAstro]

Thanks Markus , I'll take a look.