Fitting a Polar Scope

[Altomar718]

Hi All - This is my first post as I am fairly new to astronomy - so please be gentle !!

I hope some members may be able to answer a question for me please?

My question – I bought t a polar scope as an addition to the EQ3-2 and when the polar scope is screwed into the mount, it gets to the end of the thread and if you turn the bottom of the polar scope by the viewing end, the reticule rotates, so how do you know the reticules starting position?

If the mounts weight bar is for example pointing straight down, the reticule could be in any position to start with, so how do you align the position of the reticule in the right position in the mount?

I have watched astronomyshed.co.uk videos and understand how you use Polar Finder software or the last transit on Synscan and then setting the clock but none of this will be right if the position of the mount (direction of the weight bar) and the reticule are not aligned to start with.

Hope that makes sense !!

Chris

[skir]

This guide http://www.astro-baby.com/HEQ5/HEQ5-1.htm should work for your polar scope, it's written for an heq 5 but should be the same or similar for yours. I used it to setup a eq5 polar scope in a cg-5 mount so you should be ok.

Just be really careful to follow the information about adjusting the Allen screws/thumbscrews. I loosened mine off too much and the reticle fell out of position. It took me a while to work out what I'd done wrong but was easy to rectify.

[IanC11]

I have to totally agree with skir's reply. Astro-Baby's guide is a fantastic piece of easy to follow instruction, like you I didn't have a clue when I purchased my polar scope for a eq5 a few years back. Just followed A.B's guide and it was a breeze to set up, just take your time and follow EVERY step.

Good luck...

Ian

[Altomar718]

Thanks for the reply, but having read it, I am still not sure the actual starting position of the reticule. In the text, it says :- The first thing you need to do is release the RA lock, look through the polarscope ( focus it as you require ) and turn the RA axis until Polaris is at the bottom of the view ( see fig 4 ). - That is exactly what confuses me as the polar scope can rotate and also the RA. Having looked on YouTube, I found one clip that looked as if the correct starting position is the weight bar pointing straight up and the Polaris circle at the bottom of the view through the scope (below NCP) (as in Fig. 4) on the Astro Babys website). Then when the weight bar is rotated back to the pointing straight down position, the Polaris circle would then be at the top of the display. Does that sound right for the starting position to you please?

For example, the weight bar could be straight up but the Polaris circle could be at the top, bottom, left or right depending where the scope is rotated (and of course the reticule) in the mount, and thats what I am trying to find out, the relation between the position of the mount and that circle on the reticule and how they should line up to start with.

[Altomar718]

I have done a crappy diagram (attached) to try and explain !!! - The black spikes are supposed to be where the weight bar is pointing, so if the reticule was at the top and it was rotated, it would be different then if it was at the side when you started.

[Gonzo]

Here's another good guide,

http://www.dulcemelos.ca/astronomy/HEQ5/index.asp#onetimepart1

[Altomar718]

Thanks all for the replies, I think I have now sussed it with your help - appreciate it - Chris