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Thread: crazy spoil board fire.

  1. #1
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    Default crazy spoil board fire.

    I don't know why this happened. Was testing hole size in some 3/4" pdf that had a white laminate on it. it was a 1/4" downcut end mill at 1ips because I wanted the holes accurate. I cut the hole checked the size went back to aspire to change the tool path a bit to loosen the hole up when I see a glow coming from the hole as the machine was just starting the next test hole. I grabbed a bottle of water but turned off the dc but not the vac.I had to move the sheet to make sure it was out as it was still smoking. Now See why it had spread fast.
    it was a 3/8" hole and I was using a inside profile cut a climb and a regular.
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  2. #2
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    Default

    Using a down cut is a good way to start a fire

  3. #3
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    Default

    Plus 1 to what Jerry says. 2 types of bits start fires.... Broken and downcut
    Gary Campbell
    GCnC Control
    GCnC411(at)gmail(dot)com
    Servo Controller Upgrades
    http://www.youtube.com/user/Islaww1


    "We can not solve our problems with the same level of thinking that created them"
    Albert Einstein


  4. #4
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    Default sparks

    So is there a way to keep a spark out of the dust collector system ?
    What precautions should be taken with the dust collector ?

    So upcut bits for holes are better?

    I sometimes just mark the holes with a downcut bit and use a drill later...
    The decimal point seems to be the most important on the z axis... x & y not so much....
    ShopBot... Where even the scraps and things you mess up and throw away are cool....

  5. #5
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    Default

    if you drill or jam bit yes. but this was a 3/8" hole and I have done many sun holes with a downcut. if it was dull I can see that has happened but it was not a dull bit the only time I had issues cutting pdf was when the bit was really dull. this was one hole with a profile cut and a sharp bit. I was afraid of tearing the face with a upcut. I seldom cut laminated material so it is odd for me.

  6. #6
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    Default

    There no room for the chaff to go and it is heating up as a 1/4 inch bit is always in basically the same spot in that size hole

  7. #7
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    Default

    I have done it and 1/2" holes quote often as long as I am not drilling and not doing it on 1" material. this time was strange the bit was not even darkened like what happens when it starts getting dull. almost all my mdf cuts are with downcut bits and I never have issues unless the bit is dull and even then I have some warning with shavings packed in and really hot. this was one hole with a sharp bit ramped in.

  8. #8
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    All of that, and yet it still started a fire. Predictable when using downcuts with laminate or melamine.
    Gary Campbell
    GCnC Control
    GCnC411(at)gmail(dot)com
    Servo Controller Upgrades
    http://www.youtube.com/user/Islaww1


    "We can not solve our problems with the same level of thinking that created them"
    Albert Einstein


  9. #9
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    Default

    Quote Originally Posted by Gary Campbell View Post
    All of that, and yet it still started a fire. Predictable when using downcuts with laminate or melamine.
    thats what I Was thinking. I have only cut it a few times. I just cut it with a upcut and the surface was fine. I have this new customer they have two big cnc machines one with 2 heads and one with two beds and 8 heads. they are so busy they throw stuff my way. this was one sheet of th laminated pdf that was lamest 10' long when done and two rows holes they wanted tight. I got the first cut all setup and was testing hole size. it was rushed cause the pickup guy came early and then this happened.

  10. #10
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    Default

    What is pdf? I thought it was just a typo for mdf but it is repeated multiple times here. The only pdf I know is an extension for a computer file type.

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