Skywatcher EQ-2 declination control problem solved

[CumbrianGadgey]

Scope concerned : Skywatcher Explorer 130

Mount : Skywatcher EQ-2

Problem : Fine control using the cable stiff and limited to +/- 5^o

Hi,

This was bugging the living daylights out of me. It's my first telescope and I wondered if this tiny movement of the declination was all I was expected to have but it made it darned hard to align properly. I had to line it up with the declination thumb-lock off, almost as precisely as I would using the fine adjustment itself, and hold it there while I tightened the lock. Inevitably, I sometimes let the scope move a few degrees and then didn't have enough adjustment, so had to start again.

I started tinkering and took the push-rod assembly (that the control cable attaches to) off the mount and inspected it. The business end already looked like it had had a hard life. Next I found that the scope was restricted in its movement by the mechanism on the opposite side, which is a guided rod that is pushed out by an internal spring. The darned thing was screwed in so hard that I couldn't overcome the spring force with the adjuster. In fact it was so tight that I was already wearing a groove on the central plate that these two devices push against.

I eased off the spring tension until it was almost too slack and wound it back until it just started to move the scope around on its declination axis. Then I restored the push-rod and hey presto, I now have +/- 13^o of adjustment.

I also turned the declination adjustment around by 180^o at the same time, so that the control cable now points to the aperture, rather than the mirror end (as it's supposed to be using the diagram in the handbook). This has the added advantage that the metal pointer on the setting ring is now visible most of the time instead of being hidden away under the scope and obscured by the RA setting ring.

I'll lubricate it all up a bit better and play around with the spring tension but for now it looks like a big improvement. The spring pressure is still adequate to turn the scope, regardless of how it is orientated on the mount. If I find any drawbacks I'll let you know but for now, if anyone else has this problem, try tweaking it like I have.

Cheers.

[CumbrianGadgey]

Last update.

I used the scope tonight and it performed perfectly well. I may just increase the spring tension ever so slightly by screwing the nut in half a turn or so, but i'm happy.

More to the point, I never ran out of adjustment on the declination, despite shifting from Comet Lovejoy to the andromeda galaxy to the pleiades and then Jupiter. The only frustration i had tonight was the scope banging into one of the tripod legs when tracking Andromeda....grrr, all that leveling and aligning and stuff to do again.

Job done. They should put this in the manual, I think.