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Some more questions...?
Thanks for all the responses fellas - oneforone is quite correct re "alledged" thread types and how to check them: I thought my first stop would be the Sweetmans/Unifasteners/unimeyers or whatever their current corporate identity is (if you haven't been to them for 6 months or more they've changed their name - but I believe they have incarnations in all major cities.)
Will try for those allen key head types with an extended knurled barrel head around the allen socket first: if unavailable most probably go for home-modified hex-head or somesuch, I'm that broke (or conscious of just about being there) that I'll steer away from purpose-made stuff, what with buying the scope at Xmas and having just ordered a Brian Read Round Table Platform.(Thankfully the primary cell has all knurled heads as standard.)
My new question is this: after my first collimation attempt in 30+ years and thinkink it looked pretty reasonable, I'm wondering if I overtightened the locking screws a bit for the primary mirror cell.
Everything looked ok (all concentric, centred) but in operation I found that it was extremely hard to focus on anything below the zenith areas: more particularly on higher power. I also began to think the Crayford type 10:1 focusser was "playing up" but I may have been exacerbating my perceptions. Viewing conditions were fine and when I de-focussed (which seemed far easier than focussing?!?) the expanded star disks displated a pretty-well centred black spot for the secondary.
Another query that the notes didn't (for me!) articulate fully in describing collimation - once the cental bolt in the secondary assembly is adjusted to centre it in the drawtube is that the end of any adjusting of that bolt: in other words once its position in the tube is set are the only adjustments to be effected periodically the 3 aforementioned screws I wish to convert to knurled heads: ie will they give me the alignment (at the secondary) by concerted impinging/relaxing their thrust onto the sprung bolt assembly OR DOES THE CENTRAL BOLT AND ITS SPRING ALLWAYS HAVE TO BE RELAXED/LOOSENED BEFORE ANY ADJUSTMENTS CAN BE MADE TO THE 3 AFOREMENTIONED SCREWS?
Hoping for some erudite responses - Kokatha man. ps Happy New Year to all.
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