Surface Block settings

Surface block sizes used in surfacing are set using the “Surface Block” maintenance program in the “Setup” menu.

Open

The available fields are:

• Nom block group - Blocking rings must belong to a block group - select the block group that this particular block belongs to.

• Nom block diameter - Enter the nominal diameter of the blocking ring. For example, if the block is called a "63" but is actually 62.5, the nominal value to enter is 63.

• Nom block height - Enter the nominal height of the blocking ring. For example, if the block is called a "10" but is actually 10.2, the nominal value to enter is 10.

• Actual block diameter - Enter the actual diameter of the block. For example, if a nominal 63mm block has an actual diameter of 63.5, the 63.5 would be entered in this field

• Actual block height - Enter the actual height of the block. For example, if a nominal 10mm block has an actual height of 10.5, then 10.5 would be entered in this field

• Remarks - Enter the description for the block, this is for reference only

• Cutout for seg - If the ring has a "cutout" for a bifocal segment, check this box. This will allow this blocking ring to be used if the edge of the ring is on top of the segment. If this option is not checked, when using block selection, this block would not be used if the edge of the ring is on top of the 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.

• Cutter crash thickness - This is how thick the lens must be at the block diameter; if the blank is thinner than this value, that will trigger a cutter crash warning.

• Outside diameter - If the Outside Diameter is set, this value is used when checking blocks to ensure the blocking ring is not too large (ie would create cutter crash).

  This was added originally for labs using Coburn blocks that are 50mm, blocking blanks on blocks intended for a different base. This field allows larger diameters to be used for cutter crash checks, but without impacting thickness calculations.

• Include as dynamic - If using automatic block selection, checking this box indicates this blocking ring should be considered in the list of blocks for this blocking group.

• Dynamic sequence # - If using automatic block ring selection, indicate the sequence that this particular ring should be considered. Note that the sequence number must be unique within the blocking group (you cannot have two block rings of the same sequence within the same group).

• Maximum blank diameter - If there is a maximum blank diameter for this block ring, enter it here. Blanks with a diameter larger than this maximum will switch to a different blocking ring (assuming automatic block selection is being used).

  Note that this maximum diameter is the diameter of the blank, before cribbing.

• Maximum true curve - If there is a maximum true front curve that should be used for this blocking ring, enter it here. Blanks with a true front curve exceeding this maximum will switch to another blocking ring (assuming that automatic blocking ring selection is being used).

• Minimum/Maximum crib diameter - When doing automatic block selection for non-progressive lenses, if the crib for the blank is < minimum crib, or > than the maximum crib, selection will proceed to the next block.

• Minimum/Maximum crib diameter (progressive) - When doing automatic block selection, for progressive lenses, if the crib for the blank is < minimum crib, or > than the maximum crib, selection will proceed to the next block. Progressive lenses can have a different setting, this is to allow larger blocks to be selected for progressives, for example, to provide more support for the digital process.

• Do not use if prism needed - Some blockers, such as the CMSatisloh Blocker2000, have prism rings only for certain diameter blocks, leading to a combination of sizes where some sizes can block prism and some cannot.

  For example, the lab may have the following block sizes available:

  48x7

  53x7

  58x7

  63x7

  But, they will have prism rings ONLY for the 58mm blocks. Therefore, if prism is required on the job, and the lab wants to block the prism, some blocks must not be used.

  Checking this box causes the block to be skipped if prism is required for the job. So, if the lab wants to block prism, checking this box for all block sizes where prism rings are not available would cause the block to be skipped.

• Amount of prism in ring - For the Micro-Blocker, prism rings are available only in 2' and 4' sizes, and only for certain blocks. Adding a prism ring to the block changes the height of the block as well, effectively making a new block (for selection purposes).

  For example, a lab might have the following Micro-Blocker blocks available:

  48x10

  53z7

  58x7 (no prism)

  58x13 (2' prism)

  58x13 (4' prism)

  63x7

  The 58x13 blocks would be set up with the amount of prism in this "Amt of Prism in Ring" field. The block would only be selected if the prism required for the job was at least more than the prism in this field. If this block is selected, the prism in this field then becomes the amount of prism blocked on the job, which causes only remaining prism to be sent to the generator.

  Note that because there are two 58x13 blocks, one of them must be set up with a NOMINAL block height of 14 (or 12), to make the entry unique. The actual block height should be entered as 13.