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First, one or more "Block Groups" must be set up, under "Setup", "Surface Block Groupsgroups". By default, your Rx-Universe system will have one group, called "Blocks" or something equally generic. If desired, multiple block groups can be set up - this can allow dynamic selection of different groups of blocks for toric and digital, or for different lens styles or materials.
For example, we could have 2 blocking groups, "BLOCKER 2000" and "PRA BLOCKER" set up in Rx-Universe. The examples in this section will use this example:
Surface Blocks
The specific surface blocks (or blocking rings) s to be used for each group must be set up under "Setup", "Surface Blocks". For each blocking ring, the following must be set up:
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if the ring has a cutout for a bifocal segment, check this box. If not checked, then Rx-Universe will avoid selecting a blocking ring that will rest on top of a bifocal segment.
Extra Height
When blocking a lens with a steep curve, the front curve may theoretically "hit" the bottom of the block. In practical terms, though, since the ring is hollow, as are many (but not all) blocks, there can often be some "extra" height given to the block to accommodate these steep curves. For example, in the following diagram, the front curve can go slightly below the theoretical "bottom" of the blocking chamber:
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Separate fields are available for Progressive and Non-Progressive designs; this is to allow larger blocks to be selected for progressives, for example, to provide more support for the digital process.
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Selecting Default Block Groups
Default block groups can be set for toric and digital jobs, on the "Setup", "System Parameters" screen, "Blocking" tab:
For purposes of illustration, if we set two block groups, with blocking rings and sequences as follows:
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In addition to default block groups for toric and digital, the block group can be defined for specific lens styles, and for specific materials, on the corresponding fields, as below:
The block group to be used for selection can also be specified on the order; on the F12/Surface Opts screen:
When looking at specific blocks, in the "Forced Block Size" box, the each block is listed with the block group first, then the size. For example:
2:48.0x10.0
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The work ticket will now show not only the block size to be used, but also which group the block is for:
