AZ-EQ6 RA 'movement'

[mikeyj1]

Hi 

Anyone Else had this problem?:

My AZ-EQ6 GT has a small amount of movement in the RA axis which doesn't go away with clamping, which allows the scope to move when taking astrophotos.  

With everything clamped up (RA/DEC clutches, Alt knobs, and Az bolts), i can still move the mount head a fraction of a mm, (in any direction).  of course this gets amplified by the distance away from the head, so that at the end of the CWeight bar it is visible as a mm or so.  At the telescope (10" Newt) the movement is more pronounced, and is 'friction free' so that you can make it move even with a gentle touch.  I tried slacking all clamps off and its still there.. Any ideas what and how I need to tighten up to get rid of it?

 

thanks

Mike

[spaceman_spiff]

I also have an AZ EQ6 mount and it also has a bit of wobble in the RA and DEC axes. This is a consequence of the spacing within the worm gears, there are screws that you can tighten to reduce the wobble but it should always be present. I slightly unbalance the scope (in both RA and Dec) axes so that the mount is always engaged with the motors. Just a word of caution, I unbalance the scope just enough that the scope rests gently on one edge of the gear and more than that and you could stress the motors.

HTH

Dan

[mikeyj1]

Thanks Dan,

I usually do have some imbalance, but maybe last night it was 'perfectly balanced'. Any idea which are the adjustment screws (a pic would be great). There isn't anything on the Dec, yet..

cheers

Mike

[Starflyer]

Search for Astrobaby's EQ6 strip and rebuild tutorial. This is for a slightly different mount but the worm backlash adjustment process is the same, with the adjustment screws being in roughly the same areas.

Be aware that doing this is fiddly, time consuming and it's easy to make things worse., it's not easy to get back to a known, good, starting point.  Worm gears need an amount of backlash to work correctly, you'll never be able to adjust all the backlash out, if you try the gears will bind and the motors will stall.

That said, I adjusted my AZ-EQ6 DEC backlash to improve guiding, I'm not sure I'd ever bother with adjusting RA backlash unless it was truly terrible. RA only ever tracks in one direction so backlash isn't a problem and a slight imbalance is all that's needed.

 

Cheers,

Ian

[jambouk]

Mine had backlash in both axes which a friend resolved. You can quantify it by locking the clutch and then looking at the pointer against the setting circle and see how much it moves in terms of "degrees".

James