Newbie Collimating Advice

[todd8137]

hi ralf,and do not be put of by collimating it may seem scary but its not a took the plunge and thought " i`ll never able to do this" it took me a couple a hours but with the help of sgl and astro babys link a soon did it and its so easy do not panic the 10" will be a great scope

[Bigdaddyjeff]

Morning everyone....took delivery of my relevation deluxe collimator yesterday then spent around 2 hrs worrying whether the laser point from the collimator should actually be a rectangular marker as it is or it should be circular. Now i know i'm a relative newbie and i've looked at some demonstrations of collimation from links on here that people have posted and i'm certain my laser should be circular. I'm thinking i need to send this collimator back as it didn't come with instructions either!!! Hope some1 can help!!

[sixela]

No, that rectangular spot is a hallmark of cheap laser collimators (that's because the beam coming from the laser diode is rectangular and there's just a collimating lens and no aperture stop.)

You can fix that by hacking together your own 1mm aperture stop and installing it somewhere, though, but you'll need to be very precise. That'll give you a circular spot with a handy diffraction pattern around it.

For setting the tilt of the secondary that tool should be good if it's collimated and registers well in the focuser, even with that rectangular "dot". Just make sure to press the laser into the focuser while you tighten it, because the contact between the shoulder of the tool and the shoulder of the focuser drawtube is what prevents small tilt errors.

Turn it clockwise 60° and clamp it again a couple of times to check the laser collimator's own collimation first (and you ability to ensure it registers in a repeatable fashion!).

For setting the tilt of the primary, you're still better off with a mere collimation cap or Cheshire than with the return beam of one of these, especially with a rectangular spot on the main mirror that's hard to read with more precision than a few millimetres.