Quote:
Originally Posted by Barrykgerdes
Hi Roger
What model telescope have you got. I can probably steer you in the right direction if you put your questions to me.
Barry
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I've got a classic 12" LX200.
I haven't worked out how to accurately recreate the scenario you have mapped out in Fig2 of your document for checking the fork height, or fully understood where errors would be introduced:
- I have a metal pole 4ft tall (taller), I have clamps.
- I don't have a circular guage but have calipers and have been trying to work out if I can use them instead. I have considered buying a circular guage but am not sure if the <$50 ones are accurate enough to not introduce more error.
- I haven't worked out how to attach the guage or caliper such that it's securely held at an apprpriate height.
- I haven't worked out how to make up an equivalent of the machined bolt shown in Fig 1 and Fig 2. I have wondered if just finding a bolt of suitable thread, with a hut to clamp the DEC axis, woud be sufficent but I don't think so due to varying height of the thread?
I guess I'm just having trouble working out how to make the whole contraption rigid enough that it makes the alignment better rather than worse too
Regarding the algnment of the OTA your Method 1 where you point it at a star seems the easiest to me, but I don't understand how it works with anything less than a star that is immediately and precisely overhead. I don't really understand if the method using diffuse light source and eyepiece to focus on the RA bearing is applicable for my 12" classic, and if it's more or less accurate than the star method.
I also haven't worked out the simplist of things - what in the world I can use to wedge in under the forks to nudget the forks up by factions of a MM. Any metal I have lying around is at least 1mm in thickness, I have been wodnering what type of metal I could find which is sufficiently thin but strong enough to push in under the fork.
I hope you don't mind I have attached your fig1 and fig2 for clarity and to hopefully make the explanation clearer.
Thanks,
Roger.