EQ-2 Equitorial mount - Help pleaseeee

[Raws69]

Hi

I've recently purchased a skywatcher 130 with this mount. Reading through the instructions it mentions that once you have aligned with Polaris you need to calibrate the RA indicator by choosing a known bright object and adjust the dial to match the known settings (hope this is making sense, apologies but very new to this).

Problem i have is that the RA dial moves with the mount rather than being fixed, effectively meaning that the reading never changes. Just wondering whether this is something i can fix (loose screw??) or does this mean i should send it back for a replacement.

[Merlin66]

The RA circle is usually a "slip fit" meaning you can move it by hand and it will still move with the scope.

It's not mandatory to use the setting circles to use the scope. It's only an aid to locating objects based on their position on a star map.

The fastest way to set and use the RA is to set the scope on a bright star for which you know the coordinates and re-set the RA to suit... for the rest of the night it should be OK to use to find other objects...

Hope this helps...

Ken

[Raws69]

thanks for this, unfortunately not what i was after......

As i understand it the RA pointer / indicator should move with the mount around the dial (fixed) so that you can take a reading from the dial. My dial is moving with the mount.....

[Cornelius Varley]

The RA pointer does not move when the mount is rotated in the RA axis, this is how it is supposed to be. The dial moves when the mount is moved in the RA axis. The dial can also be rotated independantly when being used to locate an object in the sky as Ken has already explained. Your equatorial mount is working normally.

Peter

[Merlin66]

Usually there are two pointers:

One which moves with the RA circle to show the RA of the target object and the other which is fixed to the mount and shows the RA which is on the Meridian ( ie the north-south line) of the mount.

This second pointer should match with the value of the Local Siderial Time ( usually available from the Planetarium software etc)

Ken

[Cornelius Varley]

You may find these instructions helpfull Orion EQ2 instructions. The mount is identical to the Skywatcher EQ2 but the manual mentions a small locking screw for the RA setting circle that needs to be unscrewed to allow the setting circles to move independently of the RA axis. This screw is shown in the Skywatcher manual (page 15) just above the RA pointer but its use it not given.

Peter

[michael8554]

There should be three scales on your mount.

One scale is used to set the elevation of the scope to the latitude of your location, once set you don't need to routinely change it.

The Dec and RA scales are usually only a friction fit, allowing you to move them by hand, but after that they should rotate past the fixed pointers when you move the scope in Dec and RA. If they don't then they are not tight enough on their respective axis.

The Dec scale should be rotated until 90 is under the pointer when you are pointed at Polaris, which is at 90 Dec as far as the tiny scale on the EQ2 is concerned. Again you shouldn't need to move that routinely once set.

The tricky one is the RA scale. If you point your scope at say Rigel in Orion you should move the RA scale until 5Hr 15Min is under the pointer. If you then wait an hour Rigel will have moved across the sky, but of course your scope hasn't moved. If you move the scope in RA until Rigel is in view again, the RA scale says Rigel is at 6Hr 15Min - Doh! (or 4Hr 15Min, can't quite visualize it!)

So basically you set the RA scale on a known star and then quickly move to the Dec and RA of the object you are hunting for. And after you have spent 10 minutes or so looking at that object, you will have to reset the RA scale on the nearest known star to the next object you want to find.

Hope this helps

Michael

[michael8554]

There should be three scales on your mount.

One scale is used to set the elevation of the scope to the latitude of your location, once set you don't need to routinely change it.

The Dec and RA scales are usually only a friction fit, allowing you to move them by hand, but after that they should rotate past the fixed pointers when you move the scope in Dec and RA. If they don't then they are not tight enough on their respective axis.

The Dec scale should be rotated until 90 is under the pointer when you are pointed at Polaris, which is at 90 Dec as far as the tiny scale on the EQ2 is concerned. Again you shouldn't need to move that routinely once set.

The tricky one is the RA scale. If you point your scope at say Rigel in Orion you should move the RA scale until 5Hr 15Min is under the pointer. If you then wait an hour Rigel will have moved across the sky, but of course your scope hasn't moved. If you move the scope in RA until Rigel is in view again, the RA scale says Rigel is at 6Hr 15Min - Doh! (or 4Hr 15Min, can't quite visualize it!)

So basically you set the RA scale on a known star and then quickly move to the Dec and RA of the object you are hunting for. And after you have spent 10 minutes or so looking at that object, you will have to reset the RA scale on the nearest known star to the next object you want to find.

Hope this helps

Michael