Search the web
Sign In
New User? Sign Up
orion-telescopes · Orion Telescopes
? Already a member? Sign in to Yahoo!

Yahoo! Groups Tips

Did you know...
Show off your group to the world. Share a photo of your group with us.

Best of Y! Groups

   Check them out and nominate your group.
Having problems with message search? Fill out this form to ensure your group is one of the first to be migrated to the new message search system.

Messages

  Messages Help
Advanced
Collimating ED80 With Moonlite Focuser   Message List  
Reply | Forward Message #8136 of 10005 |
Re: [orion-telescopes] Re: Collimating ED80 With Moonlite Focuser

When I do an alignment, I check for centering using a target taped over the objective with a pin hole in the exact center.  I make the adjustments till the laser comes through the pinhole which I can observe in a mirror on the far wall.  I then rotate the tube in the rings to make sure the spot on the wall does not wobble.  If it does, I check for centering of the objective and the target. Ideally, the laser will exit the pinhole and stay stationary on the wall when the ota is rotated.  I use a helical centering device in the 2" focuser to insure that the laser is precisely centered in the focuser.  Once this is adjusted and aligned, I then insert the diagonal into the focuser and the laser into the diagonal.  I then shim or adjust the diagonal in the focuser until I again have the laser exiting the pinhole.  At this point, I lock down / tighten the diagonal in place without the centering device.  At this point, the optical train from the diagonal to the objective should be aligned.  Collimation of the objective (tilt) is now adjusted using the rotating ota method and confirmed with a cheshire.  Final adjustment is made out under the stars with a bright star and observing the diffraction ring pattern.  Obviously, you can not rotate the diagonal in the focuser and maintain this precise alignment so I use rotatable focusers.  I always check the alignment while rotating the focuser to confirm it is correctly manufactured,  If not, it goes back for an exchange.  Most of the new GSO crayfords seem to be pretty good for this as are the WO's.
 
I know this is not absolutely perfect, but it seems to work for me (close enough) and only needs to be done once or twice a year - ususally when temperature changes such as fall to winter and winter spring to summer.
 
Warp 

--- On Wed, 7/8/09, WayneG. <im66skidoo@...> wrote:

From: WayneG. <im66skidoo@...>
Subject: Re: [orion-telescopes] Re: Collimating ED80 With Moonlite Focuser
To: orion-telescopes@yahoogroups.com
Date: Wednesday, July 8, 2009, 10:39 PM

>
> If you simply going to accept the collimation from the factory, then
> you are assuming that every other physical property just happens to be
> perfect (rare). The only way to is to test with a laser or crosshair
> to ensure that the focuser is dead on with the exact center of the
> objective.
>
> Unless you are sending the entire scope back to Moonlight - there is
> no way (other than by chance at which point you should go buy a
> lottery ticket), that the focuser can be exactly collimated for your
> scope.
> Also... As a followup... if you wanted to be absolutely perfect in
> this alignment or as close to perfect as possible, you also need to
> make sure that the crosshair site tube or laser is precisecly centered
> in the focuser. Most focusers use either a single thumscrew to hold
> the eyepiece or a compression ring. Both of these will push the
> eyepiece, sight-tube or laser slightly to one side and off center.

All good points, Warp. Even though it was claimed the problems did not
appear until the new Moonlite was added, as was said earlier, I would go
back and confirm everything with a sight tube. I don't trust lasers for
this because they are usually not very accurate and even my $250
Lasermax, I test it in an engine lathe before using for things like
this. At least it can be adjusted.

Even if all else is right, just the act of tightening down lock screws
can throw off the squaring on of any alignment tool. I ran into this
time and again last winter trying to sort out alignment issues with an
EON80 and Premium 102.

Regards,

WayneG



Thu Jul 9, 2009 6:11 am

warpedcorp
Offline Offline
Send Email Send Email

Forward
Message #8136 of 10005 |
Expand Messages Author Sort by Date

I recently replaced the stock focuser on my ED80 with a Moonlite focuser. The focuser has collimation adjustment screws, however they may not be accessed...
peter2a6
Offline Send Email
Jul 5, 2009
6:47 pm

Hi Wayne: I replaced the original focuser since I could not achieve repeatable autofocus using FocusMax. I often operate remotely, so the autofocus capability...
peter2a6
Offline Send Email
Jul 5, 2009
11:54 pm

Peter, Ron adjusts the collimation of each focuser before they are shipped so you should not have to adjust the MoonLite Focuser's collimation when you...
David
z32lunacity
Offline Send Email
Jul 8, 2009
6:12 am

The sole reason for having collimation adjustments on the focuser (assuming everything else with the focuser is properly aligned operating) is for making...
Warp
warpedcorp
Offline Send Email
Jul 8, 2009
4:04 pm

Wayne, I replaced the Antares/GSO two speed on my Antares 1529 in April with a 2" Dual Rate MoonLite CF. There was no problem with the collimation with the...
David
z32lunacity
Offline Send Email
Jul 9, 2009
7:30 am

Also... As a followup... if you wanted to be absolutely perfect in this alignment or as close to perfect as possible, you also need to make sure that the...
Warp
warpedcorp
Offline Send Email
Jul 8, 2009
4:13 pm

When I do an alignment, I check for centering using a target taped over the objective with a pin hole in the exact center.  I make the adjustments till the...
Warp
warpedcorp
Offline Send Email
Jul 9, 2009
6:12 am
Advanced

Copyright © 2009 Yahoo! Inc. All rights reserved.
Privacy Policy - Terms of Service - Guidelines - Help