Quote:
Originally Posted by DJVege
...When I've got the Dob pointed at a target, how do I lock it in that position so that I can change EPs without it moving? I changed from my 2" 30mm to my 7mm, and the whole thing moved 20cm!!! Is there some sort of mod I can make to lock the Dob in place? If not, I can see myself buying 10" rings for the HEQ5 very soon....
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Change eyepieces?? You should be so excited that the only movement is finderscope <==> eyepiece!
I presume you mean it moved in Alt. Have you got the tension springs on? Pull them tighter - don't put the "cloth" loop over the screw - pull the spring over it! Other approach is to balance with weight. Two options:- 1) weights of some sort (lead?) wrapped up and attached with velcro to various places at the top or bottom of the scope. 2) magnets (chopped out of speakers are good) wrapped in a bit of felt. They can be placed anywhere on the tube and fine adjusted to get balance depending on eyepiece weight and elevation. But watch the angle of elevation. As you increase, the magnet can be inclined to slip. A worrying sound is the THUNK as the magnet hits the lip of the mirror cell mount and falls off into the dirt!
Quote:
Originally Posted by DJVege
...Doug and Eric, the collimation moves about a mm when moving from horizontal to vertical, however, keep in mind I didn't have the set screws locked.....
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I never tighten the three "lock" screws when I am in the field, only during transport. That's the way I was shown for my 8" and I guess I've always worried they would push the mirror out of collimation. I must experiment on the 12" - they might prevent that small change I did see??