EQ2 mount confusion

[CThody]

Hi. Sorry if this has been covered elsewhere, but I am totally baffled by the instructions for my EQ2 mount. Having set it to the celestial pole, the instructions suggest finding a star with a known coordinate, and then turning the RA ring to ensure the coordinate is aligned with the pointer. having done this it states that finding another star with known coordinates means turning the scope on the RA axis so the pointer then meets it's coordinates. Whilst that seems to make some sense, when I turn the scope on the RA axis, the ring moves with it, so the pointer always remains over the same number! Is there somethign wrong with the mount?

I hope this makes some sense, it is driving me mad! Should the scope move so the pointer moves but the dial remains stationary?

I have a Skywatcher 130m mounted to this.

Any hel;p would be much appreciated!

[Leegsi]

They are a waste of time those rings

[CThody]

I was beginning to think that myself... How do you locate a star or galaxy etc to view without them though?

[Leegsi]

Star hoping although it does take practice and I find it hard lol

[scotastro]

Like Leegsi I prefer star hopping, but I know from previous posts on SGL others have managed to use the setting circles successfully.

There should be a locking screw for the RA ring to make it rotate as you move the scope - if it is not there you will not be able to use it. The Dec disc is always locked.

The theory is quite simple if you want to try it.

Find the RA and Dec humbers for an object you want to find and also those of an obvious bright star no more than 2 or 3 degrees away from the object (eg use Vega for M57). Once the scope is polar aligned fit a low power EP and point the telescope at the bright star, rotate the RA ring until you have the star co-ordinates set (you only use the hours and minutes numbers). Check that the Dec figure is correct too. Lock the RA disc with the screw. Now move the scope looking at the RA disc until it reads the numbers for the object. Lock the RA axis in place. Move the DEC axis so its disc reads the correct numbers. Lock that axis. If you are lucky the object should be in the field of view.

The RA and Dec discs on the EQ2 mount are quite small and rather inaccurate to use. A further down side with the method (ignoring the inaccurate discs) is that for every object you want to look at you need to point to a known star first.

Best of luck

Mike

[John]

I was beginning to think that myself... How do you locate a star or galaxy etc to view without them though?

Fit a red dot type finder to your scope and get a good star atlas. It will take a little time but will be far less frustrating in long run than using the setting circles on the EQ2 I think.

John

[CThody]

Hi. thanks for the last two replies... Scotastro, that's really helpful, but I find that when the RA disc is locked it moves with the scope... When it is unlocked it allows the ring to be moved. Does this mean I need to unlock it and hold it in place while I move the scope mount and pointer to the correct oposition?

Jahmanson, a star atlas sounds a good idea to me... Could you recommend a good one that I could use?

[John]

Hi. thanks for the last two replies... Scotastro, that's really helpful, but I find that when the RA disc is locked it moves with the scope... When it is unlocked it allows the ring to be moved. Does this mean I need to unlock it and hold it in place while I move the scope mount and pointer to the correct oposition?

Jahmanson, a star atlas sounds a good idea to me... Could you recommend a good one that I could use?

Turn Left at Orion is the one generally recommended. The free planetarium software Stellarium is very usefull as well.

John

[scotastro]

The RA lock should be off when you are pointing the scope at the star first of all, so that you can set the disc to the RA numbers for that star. Then tighten the lock so that the RA disc moves with the scope. That way when the pointer for the RA disc points at the numbers for the DSO or planet you want to find you have the RA correctly set.

Mike

[robneath]

Knew I'd seen a link to a page explaining this - here