Collimating Vixen VC200L / VMC200L Optical Tubes
Copyright © 2002-2006 Vixen Co., Ltd. and Vixen North America. All rights reserved.
Vixen North America
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32 Elkay Dr.
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Chester, NY 10918
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www.VixenAmerica.com
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Version: June 13, 2006
A.
Before you start re-collimating the optics of your VC200L / VMC200L optical tubes, please read this
entire procedure thoroughly. As you reach each step, please re-read the entire step before
proceeding.
1)
The main mirror and secondary mirror of the VC200L / VMC200L optical tubes have been adjusted
to the correct position at Vixen’s factory before shipment. Make sure to mark the edge of the
mirrors and holders for correct repositioning before you remove the mirrors for any reason. It will be
very important to put the mirrors back in their original position so that you can reproduce the best
view when re-collimated.
2)
Please take care not to lose the washers between the secondary mirror holder and the center of the
spider vanes. The number of washers here differs in each unit. The distance between the primary
mirror and the secondary mirror has been adjusted precisely by using these washers.
3)
You may need to add an extension to the drawtube to collimate the focuser and the secondary
mirror. This may be the Flip Mirror system in the straight through position, or the 31.7mm / 1¼"
Eyepiece Adapter and one of the 43mm Extension Tube #AV-EA-2957 or 60mm Extension Tube
#AV-EA-2956 with the appropriate adapter rings. Unscrew the eyepiece adapter from the drawtube
if necessary to install extension tube. If you will be using a laser or a long Cheshire eyepiece, some
kind of extension is mandatory with the VC200L to prevent contact with the rear corrector lens
element
B.
Adjusting the focuser (In extreme cases: ordinarily you do not need to adjust this part)
1)
Remove the secondary mirror and holder from the front spider. Don’t forget to mark the orientation
first. Aim the scope approximately horizontally. Remove the model name sticker and loosen the 3
collimation screws (fig 1-1) one full turn. Remove the Phillips screw in the center of the spider, being
careful not to lose the washers that may drop out from between the spider and the secondary (they
may stick to either one). Leave the spider in place. To get the secondary assembly out of the tube,
aim it at the tube wall and carefully slide it between the vanes.
2)
Follow either (a) or (b) below to collimate the focuser. The visual method (a) is preferred.
a.
Attach an extension tube, rack out the focuser, and insert a centering sight tube or Cheshire
eyepiece into the eyepiece holder and look into it. As shown in figure 2, make the circle (a) of the
secondary holder concentric with the outer circle (b) formed by the edge of field at the end of the
baffle tube. Do this by adjusting the push/pull screws around the focuser (fig. 1-2). To adjust
push/pull screws, always loosen one and tighten the other of the pair. If it moves in the wrong
direction, reverse the order or move to another pair. The baffle tube will move with the focuser. Make
sure to finish by tightening all the adjusting screws.
