Help needed with Skywatcher ST80

[alan g]

Hi all, I'm looking for a bit of advice concerning my ST 8O.

I've ordered a set of tube rings for it so that I can turn the OTA when it's mounted on my EQ1 mount but I'm having a problem getting the mounting plate off the tube itself. I expected to just have to undo the two fixing screws on the plate and it would come off but when I loosen these the screws just keep turning, which suggests to me that there are nuts behind these screws which are loose and these are spinning when I loosen the fixing screws.

My next thought was that you must have to take the black rear focusing assembly off thereby allowing me to hold the plate fixing screw nuts in place while loosening the fixing screws, but when I removed the three screws from the rear assembly it withdrew only very slightly and seemed to be catching on something inside the tube.

I don't wont to pull any harder on the rear assembly in case I do it some damage. Am I missing something ?

Any help would be appreciated guys.

Thanks.

[NGC 1502]

Hi Alan. Some time ago I had a very similar scope, it was branded 'Orion' the US firm, but probably came from the same factory.

The front lens cell could be unscrewed as a unit, without of course disturbing the lens elements within the lens cell. You could put two pieces of tape, one on the tube, and one on the cell, with a pencil mark on each, you can refit to the exact original position. Hopefully that would give access to the nuts inside the tube.

I think the ST 80 is a great grab n go or travel scope.

HTH, Ed.

[JamesF]

Not sure removing the cell will help if there are baffles in the tube. I can't recall i the ST80 does or not. I'd have thought the focuser should just come off if you remove the three screws holding it in though.

If you fully extend the focuser tube can you look down it/shine a torch down it and see any screws on the inside of the dovetail?

James

[NGC 1502]

Post #3

Hi James, the scope I had did have baffles, but they were shallow, so access to any screws inside the tube should be ok.

But I'd have thought the focuser should come off with a bit of 'jiggling around'

Regards, Ed.

[JamesF]

But I'd have thought the focuser should come off with a bit of 'jiggling around'

Quite. I suspect it's just a bit of a snug fit.

James

[alan g]

Hi Ed and James, thanks for the replies. I've just watched a video on youtube and I think your right in that it is just a snug fit as there is nothing shown on the stripdown video that could be catching on anything. I will have another go, just didn't wont to damage anything.

Thanks again for the help guys.