Alternative polar scope

[TidaLpHasE]

Hi All, i just purchased an eq5 mount with dual axis drives, without the polar scope.

My question is, would i be able to mount a green lazer pointer inside the tube in place of the polar scope?

With a bit of experimenting with plastic tubes etc, i think i might just be able to do it.

Would this be a better way of getting the mount pointing to where it should be? i really think this will work, as long as i can center the lazer pointer.

Any comments or laughs welcome.

[h0ughy]

no not stupid but you cant see octans? so how would you align it?

[Lee]

How do you see it with the crappy little polar scope though???

[TidaLpHasE]

:)Gday Houghy, i have all but given up on imaging from my back yard. The block behind me that was vacant, now has a house with lights on all hours of the night:(

I am happy to drive down the coast away from the light pollution, or to the country, to get a beautiful dark sky.

From these spots, i can see Octans no problem at all,

Do you think it would work?

[h0ughy]

unless you have the sope perfectly aligned with the mount, no, as a pointer on the scope yes. you really need a polar scope in parallel with the axis of the scope, and nothing beats lining that up except drift alignment:D

[TidaLpHasE]

:)Thanks Dave, i think that i would be able to get it aligned pretty good with the axis of the mount, i will give it a go, nothing to lose really.

I will be using this set-up with only the cameras on, no scope at all, so drift aligning is ruled out, unless i can get a very small finder to accept my 1.25" illuminated reticle.

:shrug:

[rogerg]

I think your logic is sound. Providing the laser is correctly in alignment with the tube that would have held the polar scope, you should be right. I've often thought of doing exactly what you're suggesting but haven't because the on/off switch for my laser is near it's front, but I need to mount the front inside the tube - so sort of doesn't work. I instead hold the laser against a flat part of my mount that is also in alignment with the polar axis.

If you had a scope on the mount you could then use it with a medium power eyepiece to get the green laser dead smack bang on the SCP, just off to the side of Sigma Oct. This is what I do. Note that the laser would still be aligned to the mount not the scope but you use the scope to view the stars & laser at high power enabling greater accuracy.

Roger.

[danielsun]

Yes Trevor , i have done exactly that.
I turned up a stepped aluminium sleeve that sits in the front of my polar scope hole of my eq5 and the lazer pointer snugly slides inside it.
I can point it close enough to the scp and get it fairly close.
but is better when i go to a nice dark site and can easily make out the stars in octans.
I posted a thead on this a couple of months ago when i first was about to try it.
If you do a search for my thread (polar alighning with a lazer pointer)on this forum you will find other links about this method.
Though drift alighning which i'm just learning to do is probably the most accurate.