8" LX200 Way out of collimation - where to start
Posted 09 March 2013 - 01:29 PM
I have an 8" LX200 that I recently purchased, the owner claimed he installed Bob's knobs and the scope would no longer collimate... upon arriving I was able to roughly collimate the scope, even took some decent images of Jupiter with it.
Last night I tried to fine tune the collimation, without much luck, there was also some astigmatism which I had not seen before so the scope now sits in a way off collimation state, I am wondering what the experts here would do as a starting point with an SCT that way off collimation as a starting point.
I purchased a new set of Bobs knobs in anticipation of replacing but I am not sure if I need to. My plan was to get the scope as close as I could, then replace the current Bob's knobs in the scope anyways simply because I have them. If any of you are in WI near Milwaukee and know this stuff I would be happy to pay you to come and collimate the scope... short if that I would like to hear those who know more than I do suggestions on where to start.
I really appreciate any information...
Posted 09 March 2013 - 03:55 PM
Posted 09 March 2013 - 04:21 PM
Remember this is not expert advise. My thinking is if the secondary is too loose it may not be properly centered where it needs to be. You also have to consider that the seller may have removed the corrector at some point and did not put it back on properly. This could present a very challenging situation to rectify.
Posted 09 March 2013 - 04:38 PM
That's what I was thinking only difference would be after getting them all tight and backing off a bit I would replace the bobs knobs he put in with my new ones (perhaps he purchased the wrong knobs?) and perform the rest as you state. According to the seller he never removed the corrector plate, he just thought he did something wrong and or stripped the bob's knobs... when I got the scope I am pretty sure they are not stripped at I have installed these on a couple LX200's and collimation screws never really feel "tight" from what I can tell and I think he mistook this as something being wrong.
Also do you (or anyone know) if the the mirror lock should be completely dis-engaged when collimating or should there be some pressure?
Posted 09 March 2013 - 05:02 PM
Posted 09 March 2013 - 05:53 PM
I hope this helps.
Posted 10 March 2013 - 10:13 AM
The real benefit here is you do not need to power up the mount and chase stars....
Now you can fine tune after dark...
Posted 12 March 2013 - 12:20 AM
Posted 16 March 2013 - 10:48 PM
Posted 18 March 2013 - 12:43 PM
It looks pretty even now.
Posted 18 March 2013 - 03:14 PM
That was a webcam in the back of a Meade flip mirror I believe.
Posted 29 March 2013 - 09:09 PM