secondary mirror problem?

[anjutosi]

Some days ago I noticed my c11 telescope needs collimation (an out of focus star airy disk not perfect). I bought a laser collimator that I’ll receive it in the next days, and I today looked for the collimation screws to know where they are. It was very easy.

Unfortunately I noticed the secondary mirror block is loose, it can be rotated and can move about 1mm in each direction. I know the center screw needs to be tightened, but I can’t access it. The secondary mirror block rotates and I can’t remove the secondary mirror retaining ring. All the block rotates.

Shall I force the secondary mirror retaining ring a bit? Shall I remove the corrector plate?

Anny suggestion?

Thanks

Antonio

[damnut]

Hi Anjutosi,

All you really need to do is refit the secondary and use the three small screws on the secondary to collimate, small (1/4 turns) should be all that is need. Plenty of vid on youtube on how to do this

You do not need to remove the corrector plate. If you have already (!), then make sure you have made some alignment marks and note any small pieces of packing that might be present. Putting back in exactly the same position is critical!.

Cheers

[anjutosi]

Thank you very much for your help.

Best regards,

Antonio