Piggybacking a second scope - Part II (Alignment)

[david_r]

Hi,

Following on from my last thread on this topic, I've got all the bits etc. Now I'm looking at alignment. How do you manage this?

I guess the simple way is just to select a celestial object and dial them both in to the centre of the field of view.

I was wondering though; can you purchase a cross hair on a filter type mount that screws into an EP for accurate alignment? or would this be so far out of the focussed view that you would not see the cross hair?

Also once you've aligned the second scope, and given that my set up is permanent (i.e. I shall not be disassembling it to take to other sites), is it worth a dab of threadlok once aligned, or is this a very bad idea?

As always, thanks in advance for your responses.

David.

[Merlin66]

A cross-hair eyepiece helps... ( a filter type attachment won't work unless you can get the + wires down into the aperture stop)

Just work your way up in magnification between the scopes until you're happy they both show the same centre star.

DON'T use Loctite etc on the screws.... no matter what you think now, I guarantee you will move/ relocate/ upgrade sometime in the future!!

[Doc]

You don't have to wait till dark, this job can be done during the day as long as you have an object to focus on a long way away.

Such as a ariel on someones roof, a church steeple etc. The further away the better.

Just focus on the object in your scope through your eyepiece try and get it a central as possible and then look through your finder and adjust accordinly until both images are central.

Swing away and locate agian only using finder. Look through eyepiece and object should be central.

[RichieJarvis]

And don't forget that both scopes do not need to be looking in the same direction - as long as they are locked together, they will both track the sky at the same rate. This is useful for astrophotography where you cannot find a guide-star in the field of view in the guidescope, so you offset it until you can find one.

Cheers,

Richie

[Psychobilly]

If you haven't got a cross hair EP then defocus the star its often easier to center the doughnut mode than a pin point star image...

Billy...

[beamish]

Or you can use a w/cam and set the X-hairs from something like K3Tools or PHD