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That bit shouldn't move

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About 3 months ago, I managed to take a decent(ish) picture of Orion’s nebula using my C8 and DLSR but after taking my scope on a long car journey, I just couldn’t quite duplicate the results. I used a Bahtinov mask, but even when in focus, it just wasn't focused enough. Believing the collimation to be out, I followed an online guide and began tweaking those pesky screws on the secondary mirror. As I began tightening one of the screws, I noticed the entire assembly that holds the mirror rotated about 10 degrees! It would seem that the mount that fits into the front lens wasn’t at all tight and whole thing was spinning freely. I managed to remove the outer ring (the bit that comes off for Fastar), extract the mirror and re-tighten the mount but I couldn’t see exactly what it was tightening against. Is there a large nut on the inside? Does the glass have a thread cut into it? Should there be some thread-lock to prevent this coming loose?

I bought some Bob’s knobs and I borrowed a friend’s HOTECH Advanced CT Laser Collimator and I’m pleased to report all is well. I am however worried that there’s something wrong with my OTA and I’ll be doing this again the next time I travel with my kit. Wobbly bits and telescopes don’t mix!

Has this happened to anyone else or am I just lucky?


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