LX90 Collimation Thumbscrew Set
Installation and Use

Copyright (c) 2001 ScopeStuff

This set of three thumbscrews replaces the allen-wrench type collimation adjustment screws 
to make adjustment easier, using no tools.  Easier operation means you will be more likely 
to make the fine adjustments that will yield optimum viewing.

Don't remove any screws from the telescope until you have completely read these instructions!

This replacement procedure assumes that the telescope was collimated before starting, and will 
return it very closely to the original adjustment.

1.   Unpack the screws and make sure the washers are on the screws.

2.   In daylight, set the scope up for viewing a stationary land object (about 100 feet away
     is fine) and install an eyepiece (about 26mm).  Leave the scope powered off and use
     the ALT and AZ knobs for steering.  Refer to the owner's manual for setup.  

3.   Pick a stationary land object to view that will position the optical tube pointed slightly
     down from level.  Center the stationary object in the eyepiece and focus on the object.
     Make sure the telescope is stable and locked onto the object, with the RA and DEC
     locks engaged.

4.   Of the three collimation screws located in the center of the corrector plate, start with
     one at the top, and remove that screw with an allen wrench.  You should replace a
     screw at the bottom last, after the other two have been replaced.
   
     Do not remove more than one screw at a time!

5.   Replace the screw you removed with one of the thumbscrews.  Make sure the washer
     is on the thumbscrew.  Tighten the thumbscrew until you just feel resistance.

6.   Looking through the eyepiece, slowly tighten the thumbscrew until the object you
     centered in step 3 returns to the center of the view.  Having someone help may make
     this easier.  If you encounter a sharp increase in resistance as you tighten the
     thumbscrew, but before the object becomes centered, don't force it.  Instead, loosen
     the other two screws about 1/8 of a turn, then tighten the new thumbscrew to center
     the object.

7.   Repeat steps 4 through 6 for the other two collimation screws.


The telescope is now adjusted very close to the original collimation, but collimation should be
checked and adjusted for optimum viewing.  Refer to the telescope user's manual and follow the 
collimation procedure.  The procedure is also available on the manufacturers web site. There are 
several articles on collimation that may also be of use at www.mapug.com.