Terry, I have not tried that, but will take a look at it. Thanks for the link.
Mark the primary is fixed tight, from what I saw when I first got the OTA, it all looked pretty centred. I will take a look at the new focusor when it arrives to see if it has a centering function.
Ken, no I did not use a Tak collimation scope. Not a really wealthy man to own such a device. Yep I own Tak gear but cannot bring myself to buy a Tak collimation telescope.
