Hi all this how i achieve collimation with my truss dobs.
1: With the laser in the focuser I adjust the secondary mirror to send the laser straight back to the centre of the laser ( I dont care if its not centred on the annulus (ring) of the primary as it dont need to be at this stage) as the laser is used for collimating the secondary mirror only.
2: Take your laser out and replace it with the cheshire then adjust the primary mirror with the three thumb screws until you can see the annulus in the centre.
3: You would think its collimated now but the truth is its still way out especially if your thinking of splitting Antares.
4: Put the laser in again and you will see you have to adjust your secondary mirror again,So centre the beam up again on the return path,Then take it out.
5:Back to the cheshire and adjust your primary mirror again to get the annulus in the centre again.
6:By now your getting closer as you will see, But i,ll end now by saying keep repeating those steps maybe up to 5 times until you cant make any more adjustments and then around about 15 minutes later and your collimation will be precision accurate.
The primary locking screws in my world only are used to transport the scope NOT to lock in collimation so after collimation dont tighten them up.
I cant remember if ive posted this info before But its got to help.
Laser <-----Secondary collimation.
Cheshire <-----Primary collimation.
The pair together work like a hand in a glove.
Cheers Kev.
