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Introducing the Parallax Inc "Inventor's Wands!" - Page 2 — Parallax Forums

Introducing the Parallax Inc "Inventor's Wands!"

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  • Maddie the InternMaddie the Intern Posts: 81
    edited 2011-09-08 09:02
    Thanks Phil!
    We will be very careful (might even just order them from a printing company- we'll see)!

    I'm not allowed to just put stuff in the laser printer anyway- I get to watch. The guys know what to put in them and what not to (as I don't know either way- I go with the flow and just help in the design process!) :)

    -MaddieTheIntern
  • PublisonPublison Posts: 12,366
    edited 2011-09-08 09:07

    I'm not allowed to just put stuff in the laser printer anyway- I get to watch. The guys know what to put in them and what not to (as I don't know either way- I go with the flow and just help in the design process!) :)

    -MaddieTheIntern

    As in pumpkins? :)
  • GordonMcCombGordonMcComb Posts: 3,366
    edited 2011-09-08 10:24
    Cutting or engraving vinyl with a laser produces chlorine gas, which is not only poisonous but highly corrosive to electrical components.

    More specifically burning of vinyl releases hydrogen chloride, and upon immediate contact with moisture in the air the fumes turn into hydrochloric acid. This acid is what's corrosive to most anything but the alien in the Alien movies. (I post this for the lurkers, as I know Phil knows this. It's just a minor chemistry point.)

    There are laser cutters that work with vinyl (though waterjet is better), but they require controlled atmospheres and scrubber hoods. Parallax's laser cutter isn't one of these!

    -- Gordon
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2011-09-08 10:57
    I post this for the lurkers, as I know Phil knows this.
    Actually, I didn't. I assumed Cl2 (a powerful oxidizer) was the product. Thanks for the correction!

    -Phil
  • W9GFOW9GFO Posts: 4,010
    edited 2011-09-08 13:29
    To further confuse the issue, some products labeled as "vinyl" aren't actually made of vinyl, but a polyester or something like that. So when you hear of someone lasering vinyl without problems, they may not know that it was made of some other material.

    Real vinyl, PVC and apparently pumpkins should not be lasered.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2011-09-08 16:06
    Rich,

    'Any idea how to tell if something is vinyl? I've got some 1/16" clear acrylic which has a blue plastic protective covering on both sides, rather than paper. The plastic is stretchy, like vinyl, but it might also be polyethylene. I've been removing it before lasering, just in case, but that's causing other problems.

    -Phil
  • localrogerlocalroger Posts: 3,452
    edited 2011-09-08 17:16
    Phil, that's almost certainly polyethylene, since even Saran Wrap itself is now polyethylene according to Wiki: http://en.wikipedia.org/wiki/Saran_%28plastic%29
  • W9GFOW9GFO Posts: 4,010
    edited 2011-09-08 17:23
    The test that I have read about is to heat up a piece of copper wire with a propane torch until it is red hot. Touch the hot wire to the material to be tested then burn again. If it is green then it is not safe to laser. I have not actually performed this test myself but since it has been brought up I think I will go try it.

    edit: I can confirm that this does work. I dipped the hot wire into some PVC sheet and then put it back in the flame. There was a very visible green flame that lasted a second or two.
  • W9GFOW9GFO Posts: 4,010
    edited 2011-09-08 17:39
    Regarding the acrylic, according to Tap Plastics, extruded acrylic has the blue plastic covering and cast acrylic has the paper. I have not heard of anyone removing the plastic covering for the reason of protecting the laser.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2011-09-08 19:29
    Rich, once again, I'm in awe: you're a veritable fount of good information. Here's a photo of vinyl, deposited on copper, being devoured by the flame:

    attachment.php?attachmentid=84912&d=1315535195

    Here's a photo of the blue plastic protective film from -- you guessed it -- Tap Plastics:

    attachment.php?attachmentid=84911&d=1315535195

    No green! Yay!

    Oddly enough, though, rock salt, a known chlorine compound, does not produce the green color.

    Of course, being the perennial skeptic, I had to question why the substrate had to be copper. I can report that the test does not work with stainless steel.

    -Phil
    326 x 413 - 23K
    320 x 364 - 28K
  • Matt GillilandMatt Gilliland Posts: 1,406
    edited 2011-09-08 19:38
    extruded acrylic has the blue plastic covering and cast acrylic has the paper.
    The acrylic enclosures for our Multi-board, Gadget Gangster, etc. are protected by paper. It's usually cheaper to get it plastic coated, but I think it's pretty ugly when cut, because it sometimes tends to curl. Paper cuts nice and clean. All of our enclosures are extruded.

    We could order acrylic in plastic faced at a lower cost, but I don't like the look and nobody wants the smell :-)

    We use Cast for parts that need to be drilled or tapped (such as the mounting bracket for our HB25 -
    it's now included free with every HB25).

    The paper doesn't smell, it looks better, and seems to stay on better until you want to remove it.

    Also, the new forthcoming Acrylic Ping Stand is made from cast (and is paper faced too), as it has two holes that are tapped by screws as you twist them in.

    -Matt

    -Matt
  • W9GFOW9GFO Posts: 4,010
    edited 2011-09-08 19:48
    Come on now Matt, if you're going to correct me at least include the whole quote!
  • Matt GillilandMatt Gilliland Posts: 1,406
    edited 2011-09-08 21:35
    So sorry W9 :-) Never meant to imply "correction" - even though you're a "W9" and I'm a "KA6" :lol:. That's just the typical stock that our supplier has - we also have a Tap Plastics here too - for one reason or another (only our purchasing dept knows) - we don't buy much there.
  • jdoleckijdolecki Posts: 726
    edited 2011-10-04 10:56
    I know its an old thread but while I was looking a my Defcon Badge you guys came to mind.

    If you looking for things to burn up in that laser of yours why not create a badge for

    the Propeller expo like thay have at the Defcon event?

    Just ask Mr Joe Grand for ideas.
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