Collimation correct?

[Jason D]

5 hours ago, popeye85 said:

Sorry, don't follow.

You stated that you are unable to move the cheshire pupil reflection to the center of the primary mirror center spot reflection. I assumed what you meant is that as you were fiddling with the primary mirror adjustment knobs to move the cheshire pupil reflection, at least one of the primary mirror adjustment knob ran out of travel (was tightened all the way). That is, you are unable to continue to move the cheshire pupil reflection because some of the primary mirror adjustment knobs became too tight, correct?

[Dave In Vermont]

If the adjustment-knobs on the primary-mirror are all tight, you will have 'pinched-optics.' This will cause you problems right there. I'd suggest backing them off a way, and re-adjust the primary from square-one.

Hope this helps

Dave

[popeye85]

7 hours ago, Jason D said:

You stated that you are unable to move the cheshire pupil reflection to the center of the primary mirror center spot reflection. I assumed what you meant is that as you were fiddling with the primary mirror adjustment knobs to move the cheshire pupil reflection, at least one of the primary mirror adjustment knob ran out of travel (was tightened all the way). That is, you are unable to continue to move the cheshire pupil reflection because some of the primary mirror adjustment knobs became too tight, correct?

Ah got you now-no none of the knobs had run out of travel. I even got so frustrated that I backed then all the way it and started from scratch but still to no avail. Does it need to be bang on? How much difference will it be with it being a little bit out? 

[happy-kat]

I found the guide by moonshane really helpful.

[Jason D]

Then it is unclear to me why you are unable to move the pupil reflection to the center of the primary mirror spot!

Did you ask someone to assist? While you look through the cheshire have someone fiddle with the primary mirror adjustment knobs one at a time. Give them directions. Ask them to continue knob twists that gets the pupil reflection closer to the primary spot center and stop whenever the pupil reflection starts to move away from the center.

[rockystar]

19 hours ago, Dave In Vermont said:

Perhaps, instead of my previous offer to PM a copy of Astro_Babys' Collimation Guide if folks ask me - I'll make it easier and up-front. So here it is, what many people regard as one of the best collimation guides available:

Astro Baby's Collimation Guide.pdf

Tuck one away for a rainy day.

Dave

Consider it tucked - Thanks Dave