Time to re-check everything - collimation

[ballaratdragons]

Today, seeing as the weather is crud I thought I would spend some time dawdling along going over my 12". You know, just a maintenance do-over.

During collimation, rather than just keep sticking the dot inside the mirror centre-circle, I thought I would check the whole optical train properly.
What a suprise I got when I took the time to do a proper slow collimation!!!!

The 2ndry mirror had to be moved forwards, it was also off centre with the focuser line,
and the focuser was a bit off too. No wonder my focus had been a tad out AFTER collimation!!!

It's not a matter of 'never been done properly' either. Even Dave47Tuc checked it at Camp in March with his collimating set, and the result was that everything was spot on. Well not any more! Things shift.

After a complete re-align of ALL components my focus is already noticably better on fence posts over 2k away.

So, I suppose the point I am trying to make is: don't just rely on putting the collimation spot inside the mirror circle at collimation time. Take the time every now & then to check the whole optical train. You might get a nasty suprise. :thumbsup:

[janoskiss]

Did it make any diff to the scope's performance? A lot of collimation guides say that you can be quite sloppy with the 2ndry. I must admit I'm guilty of neglecting it. By the time I notice it's not quite right, I'm already outside and just want to observe after a quick tweak of the primary and not fumble around in the dark. I make a mental note that I have to do the secondary later, but I always forget. :rolleyes:

[iceman]

I'm with you Steve ;)

But ken's reminder is also a good one - and one I need to take up myself.

[spacezebra]

Hi all

Yes, Ken a good reminder

I ususally check both, particularly if I have been moving it around alot. I must admit that since I have removed the Meade original collimation and locking screws and went Bobs Knobs - collimation has been a dream exercise.

Cheers Petra