Restricting tilts and decenters to component groups

Question

I want to tilt and decenter a group of surfaces (or a component group) without affecting the surfaces after the group. When I try to do adjust the first surface of the component group, all surfaces after that initial surface are affected. How do I restrict the tilts and decenters so that they just affect the surfaces within the component group of interest?

Synopsis

Restricting tilts and decenters to component groups

Symptoms

Surfaces in an OSLO model are typically entered as sequential surfaces.* Because of this, if you change the tilt and/or decenter of a particular surface, all surfaces after that surface are affected. This Knowledge Base item describes how you can move certain surfaces while keeping later surfaces unchanged. * OSLO Premium offers the option of entering non-sequential surfaces, but that is a different topic.

Solution

1. Before you begin implementing the tilt or decenter, change surface 5 to a global coordinate surface by performing the steps:
   • In the "SPECIAL" column, choose "Coordinates(C)" from the pop-up list
   • Choose "Coordinates:" = "Global" from the resulting dialog window.
   • Accept the "global reference surface" as "1" in the pop-up window.
   • Accept the changes to the Coordinate Data window by closing it by clicking on the Green Check in the upper left corner of the window.
2. Now you can go to the first surface of your intended group and tilt and decenter it as you wish and only the surfaces in the intended group will be affected.

1. Perform the following steps on surface 4:
   • In the "SPECIAL" column, choose "Coordinates(C)" from the pop-up list
   • Choose "Coordinate return:" = "Yes" and
   • Choose "return to surface:" = "3" in the resulting dialog window.
   • Make sure you don't change any of the other default values in this window
   • Accept the changes to the Coordinate Data window by closing it by clicking on the Green Check in the upper left corner of the window.
2. Now go back to surface 3 (the surface we are referring to) and in the "SPECIAL" column, choose "Coordinates(C)" from the pop-up list, then
   • Choose "Use base coordinate system for r to this surface:" = "Yes"
   • Make other changes to this dialog window as you see fit to accomplish the tilts and decenters that you want to achieve on the component.
   • Accept the changes to the Coordinate Data window by closing it by clicking on the Green Check in the upper left corner of the window.