Hi there,
I'm a newbie from NZ with a new GSO 10" DOB and I'm having some fun with collimation, I bought a laser collimator with my scope (but have since ordered the CATSEYE collimation kit and a Techron sight-tube).. in the meantime I have a question about collimating with the laser (I have asked this on another forum but I'm still confused
), I have centre-spotted the mirror using a paper template (ie. removed primary and traced around it, folded template into cone, snipped off end placed over mirror and stuck a ring in the middle as accurately as possible), I have collimated the laser using a V-jig and a wall about 20 feet away. I put the collimator in the focuser (a bit sloppy, added one layer of cellotape to collimator to try and tighten it up a bit), tightened the focusor setscrew as I would with an eyepiece then adjusted the secondary tilt until the dot was right in the centre of the primary mark. I then adjust the primary until the return beam goes back thru the hole in the collimator target. so far so good, now I take my home-made collimation cap (film canister) and look thru the focusor with it and the Primary center mark is off center by about 4-5mm vertically, if I adjust the primary so the mark appears dead center thru the collimation cap then the laser beam misses the target hole. Can anyone suggest the most likely problem? I know I'll be able to get a better collimation with the tools I've ordered but in the meantime would like to try and get it as good as possible with what I have.. Thanks for any advice! Bruce.