Jump to content


Photo

12" GSO mirror removal and re-mounting

  • Please log in to reply
28 replies to this topic

#26 Mirzam

Mirzam

    Skylab

  • *****
  • Posts: 4433
  • Joined: 01 Apr 2008
  • Loc: Lovettsville, VA

Posted 01 December 2012 - 09:46 AM

Looking again at your mirror cell, you may be fine just using shims of cork or wood at the 90 degree edge positions. Because the rim around the mirror cell periphery only comes up about halfway on the mirror, it may not allow the nylon bolts to be placed at the right position (which is just a little under halfway up). As the previous commenter says, your mirror has enough thickness to get away with a minimalist edge support. Just be sure that the mirror is not pinched in the cell, or so loose as to cause problems with collimation. When you set the telescope up for viewing, raise the scope all the way to zenith and then lower it down to about 10 degrees above horizon. Then raise it to 45 degrees and collimate. This will ensure that the mirror is consistently seated in the cell and is collimated at an average viewing angle.

JimC

#27 tag1260

tag1260

    Apollo

  • *****
  • Posts: 1037
  • Joined: 07 Oct 2012
  • Loc: Ohio, USA

Posted 01 December 2012 - 07:12 PM

Thanks for all the replies.
Well, I do already have the cork mounted (In 6 positions as shown in the picture) all around the cell. Do you think I should remove the one at app. 6 o'clock and allow that area to be unsupported?

Thanks again
Tag

#28 Mirzam

Mirzam

    Skylab

  • *****
  • Posts: 4433
  • Joined: 01 Apr 2008
  • Loc: Lovettsville, VA

Posted 01 December 2012 - 08:27 PM

Probably won't matter one bit. Just be sure the mirror isn't scrunched tightly into the cell. You want the triangles to float the mirror, which will not work if the sides are held tightly by friction.

JimC

#29 tag1260

tag1260

    Apollo

  • *****
  • Posts: 1037
  • Joined: 07 Oct 2012
  • Loc: Ohio, USA

Posted 05 December 2012 - 09:55 AM

Ended up taking out the cork and letting the mirro ride on the rubber mounts from the factory. There just isn't enough room for anything in there. I "may" go ahead and put the screws in at a later time but for now the factory mounting will have to work.

I center marked my mirror with a Catseye from Catseye Collimation. I also got Jim's Catseye Chelshire eyepiece. I don't think I'll use a laser anymore. I also have an Orion Collimating eyepiece but never felt comfortable with it.

Another added addition was an Antares Twist lock Adapter for the eyepiece, getting rid og the set screw type.

Now I can't wait until a clear night (they say tonght!!!!) to try out my newly re-coated mirror and new collimation.

Thanks for listening to me throughout all of this.
Tag






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics