ZnSe Lenses needed or not ???

Results 1 to 11 of 11

Thread: ZnSe Lenses needed or not ???

  1. #1
    Registered
    Join Date
    Jan 2006
    Location
    netherlands
    Posts
    47
    Downloads
    0
    Uploads
    0

    Default ZnSe Lenses needed or not ???

    Hi all,

    I'm looking for a couple of ZnSe lenses for my 60watt co2 laser.

    My machine (lg1200) is equipped with the standard 20mm, FL= 2 inch lens, and is performing quite well with it.

    I hope that with a FL=1 inch lens it will be possible to engrave in more detail.
    and with a FL=3 or 4 inch it would cut better in thick materials like acrylic 12mm and mdf 12mm

    Is there really a big difference in performance between the different focal length's in the area of engraving and cutting?
    Or are the differences minimal?


    Also i'm looking for a good shop where i can buy these lenses at a fair price
    On ebay for example you find lenses from about 50 USD up to 200USD each.

    Does the quality of the engraving/cutting really depend on the quality/price of these lenses, or is it more something of the time the lenses will keep doing there job before they are defective?

    Best regards,

    Ferry.......

    Similar Threads:


  2. #2
    Registered
    Join Date
    Nov 2004
    Location
    usa
    Posts
    69
    Downloads
    0
    Uploads
    0

    Default

    Good questions.

    I would be interested in some good advise to your questions also.



  3. #3
    Member Tweakie's Avatar
    Join Date
    Nov 2009
    Location
    United Kingdom
    Posts
    707
    Downloads
    0
    Uploads
    0

    Default

    Hi Guys,

    Just a couple of things to consider;

    A longer focal distance lens enables a greater depth of cut (longer focal length) but has a larger spot size (width of kerf).

    A shorter focal distance lens only allows a smaller depth of cut but has a much smaller spot size.

    When cutting 10mm acrylic the short FD lens produces more barreling on the edges than a long FD lens but (from my experience so far) a better quality edge.

    Tweakie.

    Attached Thumbnails Attached Thumbnails ZnSe Lenses needed or not ???-lens1-jpg   ZnSe Lenses needed or not ???-girl1-jpg  
    CNC is only limited by our imagination.


  4. #4
    Registered
    Join Date
    Nov 2004
    Location
    usa
    Posts
    69
    Downloads
    0
    Uploads
    0

    Default

    Tweakie

    Thanks for the excellant diagram. Most helpful.

    Should a longer Focal Lens also yield a faster speed and or less charring when cutting wood?

    Larry



  5. #5
    Member Tweakie's Avatar
    Join Date
    Nov 2009
    Location
    United Kingdom
    Posts
    707
    Downloads
    0
    Uploads
    0

    Default

    Larry,

    Should a longer Focal Lens also yield a faster speed and or less charring when cutting wood?
    Don't know about faster speed. The feedrate and laser power setting are so closely related that it is probably just the material being cut that determines the speed (acrylic likes being cut slow and wood likes being cut quick).
    As for charring, I think that using Nitrogen as the assist gas is perhaps the only way to prevent it. (haven't had a chance to try it yet though).

    Tweakie.

    CNC is only limited by our imagination.


  6. #6
    Registered
    Join Date
    Jan 2006
    Location
    netherlands
    Posts
    47
    Downloads
    0
    Uploads
    0

    Default

    Tweakie,

    Can you give me an estimate for the difference in spot-size between a 1" and 2" lens ?
    does it really make a big difference in engraving quality ?



  7. #7
    Registered Litografa's Avatar
    Join Date
    Jul 2008
    Location
    Lithuania
    Posts
    776
    Downloads
    0
    Uploads
    0

    Default

    I can't provide exact numbers, but can say that engraving quality between 1,5 and 2" lenses are really big. Engraving lines with 1.5" lens much thinner.



  8. #8
    Registered
    Join Date
    Jan 2006
    Location
    netherlands
    Posts
    47
    Downloads
    0
    Uploads
    0

    Default

    Ok, thats great to hear!

    Do you have experience with the different price's they ask for ZnSe lenses.

    For example i need a 20mm lens FL=1" i've got price's between 45$ and well over 180$ both of them suitable for CO2 laser.

    I'm trying to understand what the reason is for this big price difference. Is it just the amount of profit a shop is making, or is the a real difference in quality or lifespan of the lenses?



  9. #9
    Registered Litografa's Avatar
    Join Date
    Jul 2008
    Location
    Lithuania
    Posts
    776
    Downloads
    0
    Uploads
    0

    Default

    We are selling only original GCC lens. For example our sales price is 190 Euro. But I know customers who use this lens for 4-6 years working at least 3 hours per day/ 6 days per week.
    So really price depend from quality. I am personally do not believe "quality optics made in China". Good optics are made in Singapore, USA, Germany.

    Attached Thumbnails Attached Thumbnails ZnSe Lenses needed or not ???-new-lens-spirit-jpg   ZnSe Lenses needed or not ???-box-jpg  


  10. #10
    Registered
    Join Date
    Jan 2006
    Location
    USA
    Posts
    2985
    Downloads
    0
    Uploads
    0

    Default

    Did you ever look through an expensive pair of binoculars compared to a $20 toy pair? If so, you would see a huge difference in quality. The same is true with these lenses. A high quality lens will give you a nice tight focus with a small spot size. A cheaper lens may have some weirdness so the focused spot may be oblong or have a funny shape which will reduce power density and can adversely affect cutting or marking tasks. Buy what you can afford now and then save up for a better one if you find you need it. As stated above, if you keep your lens clean, it should last a very, very long time.



  11. #11

    Default Re: ZnSe Lenses needed or not ???

    Quote Originally Posted by Litografa View Post
    We are selling only original GCC lens. For example our sales price is 190 Euro. But I know customers who use this lens for 4-6 years working at least 3 hours per day/ 6 days per week.
    So really price depend from quality. I am personally do not believe "quality optics made in China". Good optics are made in Singapore, USA, Germany.
    now this kind of lens has one model made in china,but quality is so so

    tina from g.weike laser
    EMAIL: tina@wklaser.com SKYPE: lysunshine521


Tags for this Thread

Posting Permissions

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


About CNCzone.com

    We are the largest and most active discussion forum for manufacturing industry. The site is 100% free to join and use, so join today!

Follow us on


Our Brands

ZnSe Lenses needed or not ???

ZnSe Lenses needed or not ???