position of telescope on mount

[cadams]

Hi

I am a complete beginner and I am just setting up a Celestron AVX mount with the Celestron 8inch Newtonian.  Can anyone tell me if it matters where the dovetail bar is positioned on the mount (ie back, front or middle)?  From my point of view it would seem sensible to have it so the eyepiece was as low as possible for ease of use.  However, I imagine that other factors such as balance and possibility of the telescope hitting something when being driven could come into play.

So please forgive the basicness of the question but I thought it best to find out the definitive answer before I complete the set up.

Thanks in advance

Chris

[Pint Of Stellar]

Hi Chris - you would usually want to balance the scope on the mount (in both RA and dec) especially if using the motors on the mount to drive it to point at various points in the night sky.

Check out this video for some details around this:

[cadams]

Hi

Thanks for the link to the video.

I should have read further in the manual as I have just read the DEC balance bit and this explains where to position the telescope tube.

Thanks again

Chris

[ollypenrice]

The scope has to be balanced, of course, but should you have the scope up or down in the rings and the dovetail up or down in the saddle plate on the mount? I would vote for a central-ish dovetail in saddle plate. It is then easier to fine tune by moving the dovetail in the saddle.

Do you have safety bolts in your dovetail? That is, bolts threaded into each end to stop the dovetail sliding right through the saddle? If not, put some in immedeiately. Seriously, dovetails do slide through saddle plates in untoward moments. Then there is a tinkling sound of the kind nobody likes...

Olly

[cadams]

Thanks for the advice Olly.  There are two safety bolts at the ends.  I can imagine how easy it is for the weight of the scope to cause it to slide through.

On another point.  What is the knurled plastic disc that threads onto a threaded metal dowel that comes out of one of the telescope rings for?  The other ring has a hole for a similar threaded dowel but is empty.

[bogdog]

that will be to attach a dslr camera on then run the disc up until it tightens on camera base