180 Mak collimation issue

[ET_PhoneHome]

I recently tweaked the collimation on my Skywatcher mak, and had it looking really good.  I think I was using Aldeberan for the adjustments.  Anyway, I moved the scope to a star in another part of the sky, and to my dismay, the collimation was off!  All the screws were tightened, so it wasn't that.  I went back to the original star, and it looked spot on.  I'm guessing maybe the mirror is moving slightly as the scope changes orientation.  Whatever the cause, the scope is basically impossible to collimate at this point.  I'm going to reach out to Skywatcher to see what they say, as it should still be under warranty.  Anyone ever run into this problem?  What a disappointment...

[M40]

That sounds unfortunate, I’ve been lucky in that I have not needed to worry about collimation on the skymax to date so can't offer anything useful there, but this thread in diy astronomy might help..... all the best.

 

 

[ET_PhoneHome]

Thanks.  It's only a few months old, so I'm going to reach out to the company.  It's super frustrating.  I thought I had it looking really good, and then when the scope moved to another angle.....crap.

[dweller25]

You may find it easier to discuss this with your supplier rather than Skywatcher.

Best of luck 👍

Edited February 20 by dweller25

[Avocette]

On 20/02/2023 at 05:36, ET_PhoneHome said:

I recently tweaked the collimation on my Skywatcher mak, and had it looking really good.  I think I was using Aldeberan for the adjustments.  Anyway, I moved the scope to a star in another part of the sky, and to my dismay, the collimation was off!  All the screws were tightened, so it wasn't that.  I went back to the original star, and it looked spot on.  I'm guessing maybe the mirror is moving slightly as the scope changes orientation.  Whatever the cause, the scope is basically impossible to collimate at this point.  I'm going to reach out to Skywatcher to see what they say, as it should still be under warranty.  Anyone ever run into this problem?  What a disappointment...

‘Anyone ever run into this problem?’  Mak owners regularly run into this issue! It’s variously known as mirror shift or mirror slop and is due to the way the primary mirror slides along the primary baffle tube for focusing. Did your mount perform a meridian flip when you steered from the collimation star to the other target?

Not so many Mak owners adjust collimation early in ownership, and not unless something deliberate or accidental causes a collimation shift. 

[ET_PhoneHome]

On 20/02/2023 at 09:38, dweller25 said:

You may find it easier to discuss this with your supplier rather than Skywatcher.

Best of luck 👍

Thanks.  I did reach out to the vendor.  Waiting for a reply.

[ET_PhoneHome]

8 hours ago, Avocette said:

‘Anyone ever run into this problem?’  Mak owners regularly run into this issue! It’s variously known as mirror shift or mirror slop and is due to the way the primary mirror slides along the primary baffle tube for focusing. Did your mount perform a meridian flip when you steered from the collimation star to the other target?

Not so many Mak owners adjust collimation early in ownership, and not unless something deliberate or accidental causes a collimation shift. 

Bingo!  That's exactly what happened.  I collimated on a star, and when I went to a new star, the scope did a meridian flip.  The new star test was noticeably off.

I wasn't planning on having to mess with collimation right away, but it appeared to be slightly off upon arrival.  I had it dialed in really nice, but as soon as it flipped, it looked bad.  Really disappointed.  I'll wait and see what the vendor says.  Skywatcher replied to me the other day asking if I locked the mirror down with the small screws after collimating, which I did.