Help aligning finderscope on SW Explorer 150PL

[snapper]

Hi guys,

I bought my wife a SW Explorer 150PL for xmas and we have already been out on the few clear nights between xmas and now and successfully viewed the moon and a couple of stars. However, we are having real trouble aligning the finderscope with the actual scope. No matter what combination of thumbscrew pressure, position of the finder, with the small rubber o-ring or without it, we just cant get it lined up. The best we can seem to do is to get the finder to point to an area about 1cm to the right and above the actual spot we are looking at through the scope. Is there something we are missing here? We have done this in the daytime, pointing at a telegraph pole about a mile away with the 25mm eyepiece. We just cant get it right.

Any ideas

Thanks

Mark

[Cornelius Varley]

I could be that the dovetail base on the telescope is not aligned properly. Adjust the alignment screws on the finderscope so that the finder is central in its holder then check that the dovetail is pointing straight ahead. The dovetail base can be adjusted a little by loosening the screws holding it to the telescope slightly then readjust the dovetail base and retighten the screws holding it.

Peter

[barkis]

There are two adjustment screws on the finder. The third is a spring loaded plunger. Loosen the two screws as far as you can without them falling out. Best done in daylight in case they do.

Once they are loose manipulate the scope with your hand whilst looking through the eyepiece. This should demonstrate how much movement it available. Then having centred your main telescope on a Terrestrial target ie, a chimney pot as far away as you can get one. Lock the RA and Declination clutches, so the scope can't move away off the pot. Keep checking to make sure. Once you are satisfied, gently manipulate the finder, which is stll loose, and see if you can locate the target Chimney pot. If you can, you then know for sure that it can be centred by screwing in the adjustment screws.

Do this a little at at a time. Choose the screw that will take the finder close to the target. Once you are near it, screw in the other screw, until the target starts to move the wrong way then stop.

You are now close, and by gentle in and out movement of each screw, you should be able to get the chimney pot bang on the crosshair of the finder. Once you have it there, you can use a higher magnification on the main telescope, and re centre the target. Go back to the finder, and make further minor adjustments to centre on the crosshair. You then have both scopes exactly lined up, and the finder will be of great help when locating night time targets.

Persevere, you will manage to do this.

Ron.