collimating a skywatcher 80ed

[Carl]

Any companied out there doing collimations for 80ed scopes?

Cheers Carl

[casstony]

Carl, Bintel would be able to do it, or if you read this procedure you might be able to do it yourself:
http://www.spacealberta.com/equipmen.../collimate.htm

[White Rabbit]

Don't do it yourself, there are actually very few people in oz that can do it. If you stuff it up you may as well buy another scope. Bintel can't do it either.

A little while ago I set up my 102 in the late afternoon as the sky's were clear. I went back in the house and waited for darkness to fall. A storm rolled in and my gear got soaked. Some water had gotten trapped between the two lenses. I took it to bintel to see if the could open it and clean it for me, they couldn't because no one here can collimate refractors. I would need to send it back to the us to get serviced. Luckily they were able to get rid of the water with no visible water stains between the two lenses, the got rid of the water by leaving it in an oven on at 50 deg, and evaporated it all away. Never charged me penny for it either.

So I wouldn't mess around with it.

Sandy

[casstony]

Roger from Melbourne Bintel used to offer a service of re-spacing achromatic doublets.

The lens elements are probably not decentered anyway, just a matter of improving collimation by adjusting the focuser.

I think doublets are not so difficult to collimate. You've got two elements separated by three spacers, some cells have tiny screws at the side of the elements to adjust centering, some cells have screws to adjust the tilt of the cell with respect to the tube. Use an artificial star to check progress - how hard can it be
Might have to buy myself a cheap achro to find out.

[Exfso (Peter)]

I would be very wary of anyone here collimating refractors, I had been recommended a mob in Sydney by the Tak distributor as I had a TOA130 out of collimation due to getting a strong bump in my observatory. This mob totally stuffed the scope up and it eventually had to be sent back to Japan to get the collimation done properly. The whole lens cell assembly had to be disassembled and re-built in the tak factory after these clowns performed their dissection. I know the tak is different from the ED80, but the principal is similar, horses for courses, dont let amateurs get hold of refractors, it will end in tears, expensive ones as well.

[DavidTrap (David)]

I know of someone who disassembled an Orion ST80 - not sure why.

Took him a while to get it back together correctly, but eventually it worked. Fortunately it is a guide scope only, so image quality isn't high on the priority list.

Personally, I'll be following Peter's advice.

DT

[Merlin66 (Ken)]

You can at least check the collimation of your refractor....
Use a laser collimator in the focuser to see if the beam hits the exact centre of the lens ( a paper disk with the centre marked taped over the objective.)
Then a Cheshire eyepiece and a bright LED torch; leave the cover on the objective and look at the circles/ doughnuts formed by the reflections of the lens surfaces...these should all be regular and concentric.

[DavidU (Dave)]

This is what I do. I have collimated and re shimmed the air gap on 3 of my refractors, however I don't think I would ever be game to do someone else's scope.

Originally Posted by Merlin66

You can at least check the collimation of your refractor....
Use a laser collimator in the focuser to see if the beam hits the exact centre of the lens ( a paper disk with the centre marked taped over the objective.)
Then a Cheshire eyepiece and a bright LED torch; leave the cover on the objective and look at the circles/ doughnuts formed by the reflections of the lens surfaces...these should all be regular and concentric.