Quote:
Originally Posted by pmrid
I’ve had several sessions with this TSRCKOLLI and have mixed feelings about it.
1. I can’t fully insert it into my 2” Moonlite focusers.
2. I can’t clearly identify the primary mirror shadow.
But I am happy to report a cheap and simple daylight method that looks a lot better.
An article in the British Astro Org web site entitled Kitchen table collimation ....” http://articles.adsabs.harvard.edu/p...BAA..125..281S
looks to me to be even more accurate than the artificial star technique. I plan to try it this weekend.
Peter |
Yes, as posted before the DIY illuminated collimation target gave me great results in tuning my Classical Cassegrain. I did not have to buy anything to build it. I used a bicycle LED headlight module (removed the mounting strap), a cardboard box, and a printed target. Just mount the target on the box, place a 1mm hole in the centre of the target, and duct tape the LED light to the insude of the box (facing outward of course).
Using it is very simple, just set everything up on a kitchen table, with the scope pointing at the targrt make sure it is square on. Slide the scope forward or backward to get the distance right, you want the rings to line up with your tube, and you may have to raise or lower the box to achieve this. Now turn on the LED, and you will see a white donut reflected onto the target, this is the reflection off the primary mirror. You can slide the scope backward or forward to get the donut as small as possible. Now do your primary adjustment to centre the donut around the LED source on the target.
Your primary mirror is now perfectly optically aligned on-axis with the scope.
Secondary alignment still needs to be checked too, but unless severely tilted(creating a slight shadow) it will not affect the primary setup, as you have setup the primary already.
Of course follow this up with a star test, for final tweaking if required, but don't touch the primary again.
I only bought the TSRCRolli after my kitchen bench primary setup.
Good luck.