many of these laser colimators, themselves need collimating !
This because the laser module inside can get out of alignment with the casing.
I know there is an article on it somewhere, just cant lay my hands on it right now ?
To check the collimator, make a jig out of timber with two pieces cut into a v. screw both pieces to a flat piece of timber and then place the collimator in the V's length ways. Get a piece of white paper and put it around 10 feet away and turn on the laser and point it at the paper. Mark the paper where the laser hits and then roll the laser 90 degrees. Repeat the first step and then roll again another 90. Repeat this until you have gone all the way around. Turn off the laser and look at the marks you have left. With any luck you will have a collimator that can be adjusted. If the collimator is out adjust it and then try collimating your scope again. If the collimator cannot be adjusted and it is out return it to the place of purchase and ask for another on.
Thanks RR, saved me saying all that !
I have found that the Orion/Andrews style lasers have a good outer casing.
However the internal module is a cheap $5 laser module you pick up at most discount stores
Over tightening the screw that activates the module switch, can bend the PC board inside the module making the alignment way out !
Its fiddley but can be fixed by fitting a spacer to ensure the screw can not be overtightened.
Your 2ndary looks out of coll. Try the 'sheet of white paper bluetacked to the opposite side of the tube trick'. Adjust till it is centred in the focuser tube. Then go from this, > http://www.fpi-protostar.com/collim.htm L.
ps. Get a Cheshire site tube/combo. Much better than a laser for initial set-up. All you need really...L.
Ezy, from the pic, it appears that the 2ndary is not in the centre of the focuser tube. It should be. You have to move you head around a bit to line it up correctly. Use the white paper behind the 2ndary on the opposite side of the tube, as posted above.. Not thru the front of the t'scope...
Once again I'll say, use a film can or Cheshire. Do not rely on the laser... L.
in response to your 1st question about this in the "2x or 3x barlow" thread: What do you mean, "look down the focuser? Do you have a basic collimating tool (Cheshire), a tube with a hole in the side exposing a 45-degree angled reflective surface, pinhole at one end and cross-hairs at the other end? That is what you should be looking through to check collimation, are you?
Ezy, I'm surprised Bintel sold you a laser instead of the basic tool. I'm curious who you talked to and what they told you about collimating.
I would look after that laser if I were you because you might want to take it back and exchange it for a more suitable tool.
Thanks for the reply steve. I don't think i have a Cheshire as i dont even know what that is. All i did was took out all the eyepieces in the focuser and look down it.
Spoke with Graham down at Bintel. The laser still in brand new condition as i only used it once.
I don't really know Graham. What did he tell you about collimation? Did he show you how to use the laser? Did he explain its shortcomings and how to overcome them? Did he show/tell you about the alternatives to the laser (which experienced amateur astronomers prefer btw)?
Roger is the Guru at that shop. I always try to get his opinion on everything.
he did a demonstration on how to use the laser aligning the primary mirror from the adjustable knobs from the laser window. Other than thats about it. hmm should i go back tomorrow and return the laser?
FWIW. Addendum, The camera angle may be slightly off centre, (lighting/lens is off centre), but I would still suggest using a Cheshire instead of the laser. Do the "mechanical" centres first. L.
L.
I'm curious who you talked to and what they told you about collimating.
