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I am still checking out the Newt.
I haven't cleaned the mirrors yet.
I'm investigating the collimation and anything that might affect it.
See the pics attached.
I put my laser into the focuser and and centered the spot inside
the paper reinforcement at the center of the main mirror
by adjusting the 3 screws on the spider -
I then adjusted the 3 collimation screws on the primary mirror cell
but I noticed that the spot changes position slightly if I move the telescope from a horizontal to a vertical position.
This is not helped by the 50 mm extensions I made - years ago -
in order to achieve focus when the coma corrector
was just starting to enter the main tube -
the ideal position for it.
It was either make 3 extensions or cut the valuable carbon fiber tube
to fit the mirror cell end piece over the end of the tube.
The cantilever effect of that extra 50mm makes the lateral movement
of the primary mirror worse than stock standard.
I notice that the Newt. designs I've seen all have a lateral movement
problem as there is nothing to stop that from happening -
the collimation screws work at right angles to the sideways/lateral movement so don't help much in that regard.
I found the collimation would not hold steady from other things too:
At first I traced it to a loose grub screw in the focuser - see pic.
Tightening that made a big difference.
As per the other pics it's very difficult to know that the true center
of the focuser laser aiming is correct even though I have a
brass compression ring on the 2" to 1.25" convertor - see pic.
which should in theory hold everything perfectly in alignment.
So at the moment I'm thinking about what to do as I don't want
to be like a dog chasing its tail over problems that don't exist.
When I last used the telescope it worked very well with nice round stars
right out to all 4 corners of the KAF8300 sensor.
Any thoughts would be appreciated?
cheers
Allan
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