I have just returned from the Astronomical Society of South Australia's telescope checkup day. Very friendly bunch of folks who tried their best to collimate my telescope. There were a few other people there, all with reflectors to collimate....
The secondary was too close to the primary, so it was moved all the way back as far as possible. A spring was even removed between the spider and secondary. Looking down the tube with a Cheshire it appears to be better, and my laser collimator says everything is fine (like before), but the reflection in the spider is still offset to the left and slightly up. There is no way to center it short of fiddling with the focuser: there is no more room available to shift the secondary away from the primary. While the laser says collimation is ok and the Cheshire agrees, all the reflections are still not lined up symmetrically in the center of the eyepiece. All the collimation tutorials online suggest everything should line up. Is this a problem? I think it is.
I have a feeling I'll give Lee Andrew from Andrews Communications a call tomorrow to ask for further advice. The ASSA folks suggested the spider may need to be moved further away from the primary. Surely if my GSO 6" requires this treatment, then all other examples would too? Drilling holes in the same spot to mount the spider doesn't seem like a tricky manufacturing requirement.
Photo of current collimation:
http://users.on.net/~mmienik/photos/...on%20-%202.JPG
I'm about to take the telescope outside to do a star test...