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Hi Chrys
Bang for your buck, the GSO RC is well worth the effort. The mirrors are really good. At one point CFF were installing GSO mirrors in their RC Frames.
I had the 8” GSO and once tuned it holds collimation well.
It took a while to work out best approach for me but basically..
Upgrade the focuser. I switched to a moonlight.
Get the tilt adapter.
Get hold of the Takahashi collimation scope and the appropriate adapters. Threaded always works best
The GSO is (or was) so cheap, adding the extra for the upgrades makes sense. It’s still an economic proposition.
I use the DSO method. The principle is straight forward. Google it.
Whip out the baffle
Align the focuser using the tilt adapter
I used a farpoint laser for that. You should check the laser is collimated before hand which is straight forward using a simple jig. YouTube will help
Then iterate adjustments between the secondary and primary using the Tak. Tiny steps.
Would be a godsend if someone, maybe Joshua, machined up proper graduated adjustment knobs for the primary rather than the poxy hex heads they come with. Take a leaf out of CFF or other more expensive RCs. A little upgrade that will remove a lot of stress.
Get used to understanding the impact of push pull on your mirrors
If you go too far or have got yourself into a vicious circle, back off the primary until there is just a bit of tension evenly on the hex heads and go again. You can double check focal length by plate solving which helps identify if you have gone too far.
Remember, tiny adjustments on the primary at all times.
You asked why..
Be at one with nature and accept that the stock focuser is pants. Once you get through that then the rest is straight forward.
once the focuser is aligned, the tak collimating scope is really simple to use.
David
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