Results 1 to 8 of 8

Thread: Dumb block question

  1. #1
    Master OptiBoarder snowmonster's Avatar
    Join Date
    Jul 2005
    Location
    Somewhere
    Occupation
    Optometrist
    Posts
    1,208

    Dumb block question

    Just started generating at our office and I've got a question about blocks. I have an idea as to the answer but I want to make sure somebody else confirms it.

    What is the purpose of the line on the back side of the blocks that appears to be 45 degrees off axis from the places where the cylinder machine pins go? Here's an example:


    Thanks!

    -Steve

  2. #2
    Bad address email on file Rich R's Avatar
    Join Date
    Jun 2000
    Location
    California
    Occupation
    Optical Laboratory Technician
    Posts
    273
    Hi Steve,
    If you are talking about the smaller holes that are on the back, I have used those for removing unwanted prism by using the holes that run parrallel to the pins, or right next to them, the 45 degree line is not used they just happen to line up that way due to all the holes.
    Rich R

  3. #3
    Master OptiBoarder snowmonster's Avatar
    Join Date
    Jul 2005
    Location
    Somewhere
    Occupation
    Optometrist
    Posts
    1,208
    So does the 45 degree line serve a purpose as far as lining the block up with the lens?

    Or is it just an easy outlet for wax or alloy if you pump too much of it in?

    -Steve

  4. #4
    Master OptiBoarder OptiBoard Silver Supporter Jubilee's Avatar
    Join Date
    May 2001
    Location
    United States
    Occupation
    Dispensing Optician
    Posts
    3,197
    It is a release mechanism for when overflowing the wax or alloy, such as when blocking progressives.
    "Some believe in destiny, and some believe in fate. But I believe that happiness is something we create."-Something More by Sugarland

  5. #5
    RETIRED JRS's Avatar
    Join Date
    May 2000
    Location
    Vancouver, WA
    Occupation
    Other Optical Manufacturer or Vendor
    Posts
    862
    The small slits on the face of the blocks (lens side) are to let air escape while the alloy/wax is filling the cavity. Without the air vents, the lens might lift off the block surface.

    Was surprised to see that anyone still uses those old style Coburn "base" blocks. anyhow, depending on the lenses you use - and the generator, you might have some slight thickness issues when the block curve is not equal to the lens curve (i.e. blocking a 5.00 base lens on a 6.25 block, etc.)
    J. R. Smith


  6. #6
    Master OptiBoarder snowmonster's Avatar
    Join Date
    Jul 2005
    Location
    Somewhere
    Occupation
    Optometrist
    Posts
    1,208
    JRS - what type of blocks are you referring to that are more current then? We're not that high volume, so we have a 108 CT and I finally just got done calibrating it to get rid of any induced prism. That was nothing short of a saga, but it should be fine from now on.

    -Steve

  7. #7
    Objection! OptiBoard Gold Supporter shanbaum's Avatar
    Join Date
    May 2000
    Location
    Manchester, CT USA
    Occupation
    Other Optical Manufacturer or Vendor
    Posts
    2,976
    Quote Originally Posted by JRS View Post
    The small slits on the face of the blocks (lens side) are to let air escape while the alloy/wax is filling the cavity. Without the air vents, the lens might lift off the block surface.

    Was surprised to see that anyone still uses those old style Coburn "base" blocks. anyhow, depending on the lenses you use - and the generator, you might have some slight thickness issues when the block curve is not equal to the lens curve (i.e. blocking a 5.00 base lens on a 6.25 block, etc.)

    There are still quite a few labs using those blocks. I was under the impression that most lab systems compensate for the variation in ring diameter.

  8. #8
    RETIRED JRS's Avatar
    Join Date
    May 2000
    Location
    Vancouver, WA
    Occupation
    Other Optical Manufacturer or Vendor
    Posts
    862
    Could be Robert. I guess I'm so use to seeing LOH and StepOne blockers - neither of which use those, that I forget them. I used them for years back in the 80's - all those diameters and bases. Replacing them when they warped from the heat (deblockers), or dinged edges.

    As for software systems... yes, usually there is a compensation available in the lab setup tables, but some of the straight "calc packages" may not.
    J. R. Smith


Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Dumb lens generator question
    By snowmonster in forum General Optics and Eyecare Discussion Forum
    Replies: 12
    Last Post: 06-29-2006, 08:50 AM
  2. My dumb question ....
    By optigoddess in forum Computer and Software Help
    Replies: 2
    Last Post: 05-18-2004, 12:10 PM
  3. Dumb question...
    By Judy Canty in forum Computer and Software Help
    Replies: 11
    Last Post: 05-12-2004, 11:42 AM
  4. Ok1 How is this for dumb!
    By Mikef in forum Just Conversation
    Replies: 39
    Last Post: 02-25-2002, 05:35 AM
  5. New Kid On The Block
    By Christine in forum General Optics and Eyecare Discussion Forum
    Replies: 4
    Last Post: 06-14-2000, 03:13 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •