Welcome to Our Community

Some features disabled for guests. Register Today.

So what's a Good Laser Buy?

Discussion in 'Laser Cutters' started by GrayUK, Jun 3, 2014.

  1. GrayUK

    GrayUK Master
    Staff Member Moderator Builder

    Joined:
    May 5, 2014
    Messages:
    992
    Likes Received:
    258
    Whilst waiting for my aluminium, I've been researching the laser department, from the point of view of "burning in" after a picture carve. So I don't want to get into CO2 lasers or anything major like that. I've been looking at the Blue and Red Diode lasers. Still can't see the real difference between them apart from colour. You seem to be able to buy them at all values and all seem to do the same job.
    I heard you all slap your foreheads then!! "We've got another twit here who hasn't a clue!" I have a little, and I have been reading and reading. When I think I've got it sussed, I find something else to confuse the issue.
    Anyway, I've been looking at lasers on Kale CNC, who I believe have a good reputation in the game, and like the look of this one:-

    http://www.kalecnc.com/index.php/front/productDetails/25/18

    1Watt. 808nm. Infrared. Module Output = 1000mv. Diode Output = 1100mw.

    Why? Because it's in the middle of the range shown. It seems to be ready to go, and I can't see me getting involved with the Arduino and all that.

    So what do you think? Any good? Not powerful enough for what I want, too powerful for what I want?

    All words of Wisdom greatly accepted

    Cheers Graham
     
  2. Robert Hummel

    Robert Hummel Custom Builder
    Staff Member Moderator Builder

    Joined:
    Nov 14, 2013
    Messages:
    978
    Likes Received:
    680
    First, how much?
    No need for an arduino
    Red laser diodes are weak
    Blue will get you close to 2watts "faster burn"
    808 can't be seen " not my pref"
    I'm sure Tweakie could drop his Mach wisdom on this one.
    A lm317 diver controlled by a ttl logic relay will do the trick ;)

    See my laser v build just combined the relay schematic and lm317 then control the on off with ttl from Mach
     
  3. GrayUK

    GrayUK Master
    Staff Member Moderator Builder

    Joined:
    May 5, 2014
    Messages:
    992
    Likes Received:
    258
    Whoops! :oops: Forgot to mention, had hoped to run the CNC from the USB Controller. Would that be possible for the laser side of things? :confused: Or should I run two programs?

    I meant to mention about the Video Tweakie did on the mounted camera location thing etc. Can I do that with the USB Controller as well?

    OK. We go BLUE! :cool: I need about the 2 watt mark then? I'll go and have a look.

    I'll also have a look for a "lm317 driver", and a "TTL Logic Relay". (Said in Whisper. "Does he really think I know what he's talking about?"), anyway, I'll go and look.


    Come on Tweakie, it's too early for bed. :sleepy: Actually, there's no rush. LOL

    Cheers Gray
     
  4. Robert Hummel

    Robert Hummel Custom Builder
    Staff Member Moderator Builder

    Joined:
    Nov 14, 2013
    Messages:
    978
    Likes Received:
    680
    Hahaha
    What controller are you using?
    all that is needed is a 5 vdc signal for spindle on and off
     
  5. GrayUK

    GrayUK Master
    Staff Member Moderator Builder

    Joined:
    May 5, 2014
    Messages:
    992
    Likes Received:
    258
    Planing on using the MK2 from Planet CNC.
    As an aside:- Why would you need the MK3?
    I know what an LM317 is now! :) Is the TTL Logic Relay the circuit it sits in, or something else completely?

    Already knew about Ohms Law from hundreds of years ago when I was a TV engineer. (Yes Black & White, colour was a new thing then. :thumbsup: ) To work out the values needed. You never know when something obscure like that comes in handy.

    Cheers
    Gray
     
  6. Tweakie

    Tweakie OpenBuilds Team
    Staff Member Moderator Builder

    Joined:
    Jan 18, 2014
    Messages:
    786
    Likes Received:
    297
    Hi Gray,

    Just my opinion…

    The whole subject of the use of Lasers with CNC is a relatively new concept as far as the Home or Hobby user is concerned and I think we are all learning and gaining experience ‘as we go’ (at least that’s what I am trying to do).

    I think a 1Watt diode laser would be a good starting point and as we have said before, the actual laser’s wavelength will determine how well it actually performs with different materials so it depends on your intended application as to what wavelength would be the most suitable.

    I don’t see any reason that USB cannot be used for laser control. The USB Smooth Stepper I use with Mach3 has this provision as does the Planet CNC system (good choice by the way :thumbsup:).

    Tweakie.
     
  7. GrayUK

    GrayUK Master
    Staff Member Moderator Builder

    Joined:
    May 5, 2014
    Messages:
    992
    Likes Received:
    258
    Right, well you know I initially plan to use it to burn in the detail on previously carved pictures, like those examples you had. Probably set the Diode up next to the router, with an offset set up, until there comes a need for a dedicated machine.

    Glad I can use the USB Controller. (OH. Also saw I can use a camera with the USB Controller as you were demonstrating. Trouble is I think I need the MK3 which is a bit dearer, but I need to future-proof a bit here.)

    I know 1 to 2 watts is good. I know Blue is good. If I use a 2watt instead of a 1watt, can I burn faster?
    I know a bit about a LM317 and it's accompanying board, and how the resistors affect the values and power.

    Now talk to me about wavelength? Blue is the wavelength I'm after right?

    Been looking on Ebay. Tell me. Do lasers come in same value, but different quality?

    This looks a good one. Price is about right. Yes?
    http://www.ebay.co.uk/itm/2W-445nm-...909?pt=LH_DefaultDomain_0&hash=item2a2158fe9d

    Do the lenses make a great deal of difference? What does the -445nm- mean? :confused:

    Questions - Questions - Questions. :rolleyes:

    Colour? I felt like a change. :)

    Cheers
    Gray
     
  8. JustinTime

    JustinTime Master
    Builder

    Joined:
    Dec 18, 2013
    Messages:
    917
    Likes Received:
    180
    The nm stands for nanometer, as in the wavelength of the laser.

    Yes, the lenses make a difference but Tweakie can elaborate on it better than I can.
     
  9. Tweakie

    Tweakie OpenBuilds Team
    Staff Member Moderator Builder

    Joined:
    Jan 18, 2014
    Messages:
    786
    Likes Received:
    297
    As JustinTime has said the lenses do make a big difference but opinion is divided - some say the G2 lens is better than the 3 element lens whereas others say the opposite. I have no practical experience of using these different lenses so cannot say one way or the other.

    Certainly the more laser power you have the faster the feed-rate you will be able to use.

    When purchasing a diode laser you must know it's specification (voltage and maximum current rating) - get these parameters wrong when setting it up and you will just have a very expensive LED. The difference between bright and blown is a gnat's whisker. I have blown a couple in the past and so have many others.

    I have no idea about the quality of the diode lasers sold on the bay so you are on your own with that one. :(

    Tweakie.
     
  10. Robert Hummel

    Robert Hummel Custom Builder
    Staff Member Moderator Builder

    Joined:
    Nov 14, 2013
    Messages:
    978
    Likes Received:
    680
    Most 1-2 watt 445nm diodes are salvaged from un-used M140 projectors.
    The ideal voltage is 7 vdc
    Current 1.25
    I supply my LM317 with 12vdc adjust the output to 7 feed that through the relay to constant current 317 and set it's max current to 1.25
    I run my diode at 1 amp to save some life.
     
  11. michel pet

    michel pet Well-Known
    Builder

    Joined:
    Jan 9, 2014
    Messages:
    20
    Likes Received:
    3

Share This Page

  • About Us

    The OpenBuilds Team is dedicated helping you to Dream it - Build it - Share it! Collaborate on our forums and be sure to visit the Part Store for all your Building needs!
  • Like us on Facebook

  • Support Open Source FairShare Program!

    OpenBuilds FairShare Give Back Program provides resources to Open Source projects, developers and schools around the world. Invest in your future by helping others develop theirs!

    Donate to FairShare!