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Old 24-02-2015, 06:31 PM
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Allan
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Join Date: Feb 2013
Location: Newcastle
Posts: 937
Scott, what laser collimator do you have? Cheap collimators often ad their own errors into the system and are best avoided. You can collimate with your eyes closed using a good quality laser collimator like the Glatter collimators, but they aren't cheap unfortunately.

A pinched primary is often the reason for out of round stars. Check that the mirror clips are not touching the surface of the mirror. They should be a fraction of a millimetre above the surface, enough to slide a business card between the gap.

Your secondary mirror vains are not straight, that is giving you the diffraction spikes that don't line up. To see what I mean get a piece of cotton and hold it tight. Now place the ends over the ends of the spider vains where they attach to the tube. You will see where they attach to the hub in the centre that they aren't aligned with the cotton. Sounds like the horizontal vains might be ok, but the vertical ones need adjusting. If so you will have to straighten up the vertical vains by moving the hub in the centre. Do this by loosening and tightening the opposite horizontal vains where they attach into the tube.
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