[Geoff]

Hi from Geoff,
I turned up a lazer collimator and used a small lazer pointer in it which is adjustable with grub screws for centralizing. It has a target on a 45 degree angle so you can adjust the primary while standing at the back of the scope, and see the result. The lazer is the only way to go. very quick and easy.
Centre dot the primary with a stick on round piece of binder support. It is about 8 mm diam with a 3 mm hole. Check the internet on the best way to do this.
After using the Lazer, use an Auto collimator which is like an eyepiece with only a small hole about 3 mm which looks through a 3mm hole through the back of a mirror stuck inside. This thing gives a very fine final adjustment.
The auto collimator costs about $100 and has a good set of collimating instructions. I made my own for about $5.
I find that the Lazer on its own and a star test is good enough.
Cheers
Geoff