Quote:
Originally Posted by erick
Sorry gentlemen, for the delay. I was thinking about it.
Fundamentally the issue is both a philosophical one and the desire to meet a challenge.
Philosophically, I like to be able to continuously see the effect of any adjustment. As it is, when I am using Cheshire or Autocollimator, I need to tweak and return to eyepiece, tweak and return to eyepiece. I just don't like it. And after I worked out a likely solution, then I had this challenge in front of me to meet. OK, it's just me.
Now, my scope has usually held collimation well, between dismantling and rebuild. Just a tweak needed. But a few times it has been more than a tweak and I haven't been able to see why? I've rechecked the poles and UTA are seated correctly, and they always are. Seems the bouncing to the site had caused some movement in the secondary mirror. Now, as you will have seen elsewhere, I have had the recent scare of the scope falling over in high wind during that day. All has seemed fine since then, but I had to completely recollimate from almost scratch. I have only rebuilt the scope once since then and all was fine.
With the autocollimator, I am trying to learn how to use the "Carefully Decollimated Primary" protocol, but I find that, without a simultaneous view of what happens in the autocollimator when I adjust the primary collimation bolts, I just get lost with the reflections. So, in well known Eric style, I'll create a sledgehammer to get at this peanut!
So I don't have a logical response, sorry.
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Sounds logical to me.....or maybe I'm just as mad as you
I certainly nodded in agreement and recognition reading your post anyway, especially the parts about the likely solution and then the solution becoming a challenge to meet and the bit about creating a sledgehammer to get at the peanut.
From further discussion with Jason Khadder and Don Pensack over on CN, I get the impression that once rough collimation is done with my Glatter tools which could be done from the back of the scope, that the backwards and forwards tweaking for the Infinity XLK was minimal after some practice( It helps to position your catseye triangles or hotspot or re-orientate your mirror so the point at the collimation bolts) and thus I probably didn't really need to come up with a solution for adjusting the primary from the front. However I am like a dog with a bone who won't let go of an idea unless it turns out to really be more trouble than its worth.
In my case the idea isn't much trouble to implement because I already had all the parts so the balance point is still shifted towards implementing the idea despite it not really being necessary
My idea was canabalising a JMI TNT motor tracking system that I had modded to a point where it was unsellable anyway. (Have a servocat tracking system now). The azimuth motors and handcontroller were perfect for a motorised collimation system and I was also going to be able to use a defunct 6 wire DIN socket and wiring under my flocking inside the OTA. ie. I'd plug in the handcontroller to this socket on the OTA for collimation. Just the idea of utilising/re-purposing 2 previous but now defunct mods was enough for me to want to proceed with this mod whether it was needed or not, simply because it was recycling, sorta unique and a challenge in and off itself.
But yeah, talk about sledgehammers and peanuts!!
In terms of the need for the Autocollimator. For a scope above F4 without a paracorr any extra accuracy achieved over and above the cheshire or laser with barlow method is probably invisible accuracy. Howver once you go below F4 or use a paracorr for coma correction even on slower scopes, the collimation tolerances are tightened by a factor of 6. This is when the extra accuracy of the Autocollimator really comes into its own and is arguably visible in the eyepiece. Then again some of us are just a bit a*** retentive about knowing that everything on the scope is perfect whether that be thermal issues, stability issues or collimation issues. We want to know the scope is setup to deliver its 100% best and that if the views aren't great at least we know we did all we could do and mediocre views are down to the atmosphere and not the scope itself.
I laugh in the face of the K.I.S.S. principle....Muahahahaha!!