Laser Collimation/newtonian headaches

[tnbk00]

Hi,

I am having some headaches with collimating my reflector. I bought a laser collimator from bintel, however the issue i have is with my scope. It would appear that to make the scope more marketable the manufacturer has decided to build optics in to the focuser. (its a 4.5" saxon a couple of years old now)


The issue that i have is the return beam from the collimator gets all distorted which makes it impossible to align with the source. I have marked the center of my mirror but cantering the beam to the mark produces dissapointing results.

I was wondering if anyone has had an experience such as this. I have plans to buy an 8" dob in a couple of months anyway, but it would be nice to keep the 4.5" for friends and family etc.

Thanks

Daniel

[astro_nutt]

Hi daniel and welcome to the IIS forums..
Hmmm.....Ok..I'm not familiar with the saxon 4.5"..( I had the 8" for my first big scope) but when you say "built-in optics" I'm assuming it has a built-in 2x barlow in the focuser..that being the case..try to remove the barlow attachment from the focuser...while your there check the alignment of the focuser in relation to the tube being that the centre of the focuser points to the exact opposite with the secondary removed...also check that the centre of the foolscap reinforcement ring to mark the centre of the primary is clean.
Check the secondary's alignment in relation to the primary.
Lastly check that the laser collimator is collimated!..place it in the middle pages of a large open book and mark the spot on the wall then rotate the collimator 180 degrees and check that the beam is over the first mark.
Cheers!