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Hmm some good tips there, thanks.
One thing to point out is that I am not using the handset for the HEQ5 Pro, just the EQDirect cable and using Stellarium to drive the scope. I don't do any "alignment" procedures, I simply start the scope up via Stellarium Scope, start stellarium and then click on my first star, adjust, sync, click on one nearby, adjust, sync etc. I have looked at the built up sync points in EQAscom and it looks fine, it is just the fact that most of the time, if I have the Main ATIK CCD camera, the finderscope AND the guidescope all pointing at the same place and then I slew to say Eta Carinae Nebula, I can see in the guidecamera the region is close, but the CCD camera (narrow FOV) is never normally centred and I have to adjust again and again.
I checked the drift the other night on the main CCD camera using the crosshairs while adjusting the mount on the pier for the first time and I had a PIXEL of movement on the star in the N/S direction every 15 secs or so and almost NONE in E/W so I think I got it pretty close. This was at the native 1000mm focal length and a very narrow FOV on the Atik.
If I had left it out, or had something to cover the mount then I would have had a very good base to refine it further, but I do have texta marks on the mount and pier top plate to get me started very close next time.
The weird thing is, that if the STAR map is very accurate and I baseline the object I am centred on by synching in Stellarium on it, then slew to a nearby star (normally Mag4 or brighter) I can see that it isn't correct quite quickly. I will try Nathan's suggestion of slewing straight back again and see how that works, but I am pretty sure I have done this in the past when I get "lost" and cant find the target I am supposed to be pointing at.
I think this points me towards something mechanical like Barry suggests, like slop in the gears or too much load or perhaps even gunk in the grease.
My next exercise maybe a visual internal inspection just to see if there is anything obvious (without removing anything) as I may have some sort of defect in the worm or gear wheels which is causing the slippage.
Chris
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