Results 1 to 6 of 6

Thread: Axis problems???

  1. #1
    OptiBoard Novice
    Join Date
    Dec 2011
    Location
    Austin, Tx
    Occupation
    Optical Laboratory Technician
    Posts
    4

    Axis problems???

    Hey guys/gals,

    I need some help here. I am rather new to the industry (2 years in a small lab) and have pretty much learned what I know from a 20+ year experienced lab tech. About 6 months ago he quit on us and I took over most the technical side of the lab. The place I work has fairly dated equipment but we have been upgrading over time. The last few days we have been noticing an off axis problem with our finished glasses. I know the problem is not related to the edger, because the progressive lines and FT28's are dead even in the center (180 degrees) so I think the problem is occuring at the fining area of the lab.

    As of now I am using OptiVision software to do my RX input data. I use a manual axis layout machine (the kind with the dial that you set the axis at, and it stamps the ink before surface saving tape is applied). I have a pair of National Optronics Vista 1 generators that I used for cutting. And we are using Optical Works "506" model finer/polishing machines. Our plastic laps are worn so we rely on cutting foam laps for each job... I've been told that may not produce the best results.

    Any ideas on what could possibly be causing this axis issue to be so prevailent on some lenses, but non-existant on others? it is happening on roughly 30% of all jobs now.

    Please help

  2. #2
    OptiBoard Professional
    Join Date
    Oct 2009
    Location
    World
    Occupation
    Optical Laboratory Technician
    Posts
    129
    It would be interesting to know if axis problems are related for the low cylinder powers only.
    I am not sure in which way do you block the lenses ?

    Anyway, you need to calibrate the blocker at first, or calibrate the generator - it depends which machine is responsible for lens positioning.
    If you have possibility to do axis positioning on both, you can easily find out from which machine problems comes.

    Can you see the same problems on the lenses produced by both generators ?
    Using of foam laps have no influence to axis problem.
    Last edited by essegn; 07-02-2012 at 12:52 PM.

  3. #3
    Master OptiBoarder
    Join Date
    Mar 2010
    Location
    north of 49
    Occupation
    Dispensing Optician
    Posts
    3,002
    You got a problem, Sherlock. Now......exactly what lenses are prevalent? Which direction is the axis issue, like, both nasal down, up, or?......................

  4. #4
    Master OptiBoarder OptiBoard Silver Supporter Jubilee's Avatar
    Join Date
    May 2001
    Location
    United States
    Occupation
    Dispensing Optician
    Posts
    3,197
    As Uncut was point out.. having further info would help us narrow down the possibilities. Essentially all the major components on the surface side can affect axis.
    Marker could be off and thus putting the axis off in one direction by the same amount..
    Generator could be off axis, and needs it comp recalibrated..
    Finers and/or polishers could be off axis, and thus causing axis issues

    If the generator is off on curves, you could be off on the foam as well.

    Best thing to do is have a "calibration celebration" and give each machine a bit of love to see if it is something that is an incremental thing...
    "Some believe in destiny, and some believe in fate. But I believe that happiness is something we create."-Something More by Sugarland

  5. #5
    OptiBoard Novice
    Join Date
    Dec 2011
    Location
    Austin, Tx
    Occupation
    Optical Laboratory Technician
    Posts
    4
    Thanks for the replys... here is some further info

    -We use alloy to block lenses. 63mm steel blocks for higher minus powers and 58mm steel blocks for most plus jobs.
    -The marker looks to be right on... it stamps a line on the 180 and 90 degree marks when dialed in. I tested this by putting a dot dead center in a plano lense and the cross hit it both on 180 and 90...
    -The cylinder machines all have new pins installed as of last week. we calibrated them with the supplied steel calibration block... the markings that it makes are dead center in the calibration block, with an even pattern at 180degrees across (im not sure if this makes sense, I can post pictures if needed).
    -The tool and lens curves on the Vista 1 are calibrated as well, we check both tool and lens cuts each Monday for accuracy. I use one of the Vistas to cut lenses and the other to cut tools only.
    -I am running Polycarb on a black 3M 280 grit for 2 minutes, then on a Durafilm 15MIC tan pad for 2 minutes
    -For CR-39 and Hi Index 1.67 we do a 2 minute fine on a 600grit brown pad, then 2 minutes on a 3MIC purple pad
    -Polish 6 minutes with DAC v2100 polish and yellow supreme polish pads
    (I should mention all of these pads come from DAC)

    Low cylinder powers RX's are the constant problem for both axis and reading .12 in the power. And I also must stress the fact that this is a random problem, some sets of lenses come out just fine. Any suggestions or more questions? I can go further into detail if needed.

  6. #6
    Master OptiBoarder
    Join Date
    Mar 2010
    Location
    north of 49
    Occupation
    Dispensing Optician
    Posts
    3,002
    It sounds like you need to narrow the cause down a little bit............start by documenting the issue down to details of raw material, brand, low plus, low minus, block size used, lap used, etc. You might be experiencing the beginning of worn bearings on one polisher, or finer, or some blocks, whose pin retainers are worn. Try to record axis off direction, cylinder off power meridian and whether R or L or both. Document it all, and you will be able to pinpoint it. I know this isn't helping, much, but we're all here to help you!

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. axis?
    By dmspilot00 in forum General Optics and Eyecare Discussion Forum
    Replies: 5
    Last Post: 07-14-2008, 09:52 PM
  2. Axis Problem
    By CKPolar in forum Ophthalmic Optics
    Replies: 14
    Last Post: 06-17-2005, 11:42 PM
  3. edging axis problems
    By split pea d in forum General Optics and Eyecare Discussion Forum
    Replies: 6
    Last Post: 10-27-2004, 05:40 PM
  4. Off Axis???
    By Rex in forum General Optics and Eyecare Discussion Forum
    Replies: 5
    Last Post: 08-11-2000, 04:08 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
  •