Gooday to all--I,m fairly new to astronomy and have been sandbagging on the side reading as many threads as possible trying to clue myself in for the last 6 months or so.
I've just installed a crayford style focusser to my 10" Skywatcher Newt. and decided to collimate the optics,I used a cheshire collimator and finally got everything alligned as per instructions looked good as I took my time and was very carefull to get it as perfect as possible. I used the cheshire after reading many threads as to the supposed inaccuracy of the laser collimator which I also have. I then checked the collimation with the laser and found the laser dot to be just outside the centre spot on the primary. I have collimated the laser on precision engineers cast iron v blocks and it was spot on--(pardon the pun) so I am confident the laser isnt telling me lies but am also confident the cheshire was spot on also--which do I beleive? Also can anyone tell me why 1.250" eyepices and anything else that fits into a focusser are all accurate to a thousanth of an inch but everything that recieves them measures approx 1.256--6 thou clearance is way to sloppy! As a machinist I'm used to working with a lot closer fits than these. Could this be the reason why the discrepancy between the two collimators?--although I did rotate the laser through 3 90 deg segments and the beam did not walk around on the primary it stayed in the same position.
timelord.
