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Thread: Focal Lens

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  1. #1
    Join Date
    Apr 2010
    Posts
    0

    Focal Lens

    Has anyone hear done some shopping for a different lens other than what their machine came with ?

    My machine has a 55mm lens on the 60 watt and it cuts 9mm acrylic pretty good but the engrave is excellent, the engrave must be .010. My 150 watt has a 68mm lens and it cuts the acrylic alot better, the engrave is ok (as expected)

    While testing the engraving with the 60 watt it was tough to keep a white film from appearing on the acrylic surface, turning down the power to about 20 percent fixed that but I would like the engrave to go a little deeper, is there a trick that I dont know about ?

    Does anyone have a recomendation for a len's ? any why.

    Thanks

  2. #2
    Join Date
    Feb 2012
    Posts
    387
    Quote Originally Posted by bundysax View Post
    Has anyone hear done some shopping for a different lens other than what their machine came with ?

    My machine has a 55mm lens on the 60 watt and it cuts 9mm acrylic pretty good but the engrave is excellent, the engrave must be .010. My 150 watt has a 68mm lens and it cuts the acrylic alot better, the engrave is ok (as expected)

    While testing the engraving with the 60 watt it was tough to keep a white film from appearing on the acrylic surface, turning down the power to about 20 percent fixed that but I would like the engrave to go a little deeper, is there a trick that I dont know about ?

    Does anyone have a recomendation for a len's ? any why.

    Thanks
    bundysax
    yes,we made like this ,if machine is 50mm focus,customer need spare one ,we will suggest 63.5mm or 100mm for thick materials,but the focus distance maybe a little diffrent,so when you change to other focus,need to test the distance again,

    Any others,feel free to ask us
    Best Wishes
    Lucy Lee
    G.WEIKE LASER
    [email protected]

  3. #3
    Join Date
    Sep 2011
    Posts
    296
    Quote Originally Posted by bundysax View Post
    Has anyone hear done some shopping for a different lens other than what their machine came with ?

    My machine has a 55mm lens on the 60 watt and it cuts 9mm acrylic pretty good but the engrave is excellent, the engrave must be .010. My 150 watt has a 68mm lens and it cuts the acrylic alot better, the engrave is ok (as expected)

    While testing the engraving with the 60 watt it was tough to keep a white film from appearing on the acrylic surface, turning down the power to about 20 percent fixed that but I would like the engrave to go a little deeper, is there a trick that I dont know about ?

    Does anyone have a recomendation for a len's ? any why.

    Thanks
    Dear bundysax,

    If you want to engrave deeper, you should choose larger power and slow speed setting when engraving. And can't the white film removed? Sometimes, it can easily removed by a piece of cloth. Because we have sold many machines, i think the lens we use for engraving and cutting should be suitable.

    Melody
    [email protected] [email protected]
    skype:melody.gweike

  4. #4
    Power Density

    Depth Of Field

    best wishes

    Dave

  5. #5
    Join Date
    Apr 2010
    Posts
    0
    Thanks Dave very interesting, the power density was very interesting on how the power multiplies so much with such a little adjustment in the beam.

    What I dont understand is the focal length, I understand the principal to focus the beam to the smallest spot as possible but I dont understand the different focal lengths. From what I have read some of the most powerful lenses focal length is 100mm, why not 50mm or even 68 mm ? If you can get a nice tight beam at 50mm why would it be more powerful at 100mm ?

    Thanks

  6. #6
    Hiyaz,

    The longer focal length lens have a longer depth of field, ie: the length the beam is focussed at is longer (deeper) so making cutting thicker materials easier (they give a straighter cut) the spot size however is also bigger and as you will have read above, bigger spot = lower power density

    best wishes

    Dave

  7. #7
    Join Date
    Apr 2010
    Posts
    0
    Gotcha,

    Thanks

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