Subscribe
  1. Member Since
    Dec 2007
    Messages
    36
    Dec 15, 2007, 10:54 AM - Grinding plastic #1

    Is it possible to grind or cut grooves in plastic (say PVC) without it melting into glops?
  2. RPF Premium Member Mr_Creepy's Avatar
    Member Since
    Jun 2003
    From
    Kansas
    Messages
    965
    Dec 15, 2007, 11:02 AM - Re: Grinding plastic #2

    It's possible--I've never tried it personally, but a good friend of mine used his Dremel with router attachement & bits to make the "holes" in the barrel of his MG34 replica. I believe he carved about halfway into the thickness of the PVC--his reasoning was that leaving the pipe solid makes the barrel stronger.
  3. Member Since
    Dec 2007
    Messages
    36
    Dec 15, 2007, 11:23 AM - Re: Grinding plastic #3

    Thank you. Do you know how he did it? Like a low speed setting?
  4. RPF Premium Member Mr_Creepy's Avatar
    Member Since
    Jun 2003
    From
    Kansas
    Messages
    965
    Dec 15, 2007, 11:35 AM - Re: Grinding plastic #4

    I'd guess he used a low speed setting, but I really don't know. I sent him a link to this thread, so maybe he'll be able to chime in later
  5. Member Since
    Dec 2007
    Messages
    36
    Dec 15, 2007, 11:50 AM - Re: Grinding plastic #5

    Thanks.
  6. RPF Premium Member Hotshot's Avatar
    Member Since
    Apr 2005
    From
    Millersburg, Ohio; the Heart of Amish Country
    Messages
    2,078
    Dec 15, 2007, 11:58 AM - Re: Grinding plastic #6

    I second the low speed setting. also, taking small, little swipes at the area will reduce the heat.
  7. defstartrooper's Avatar
    Member Since
    Mar 2007
    From
    Essex UK
    Messages
    4,072
    Dec 15, 2007, 12:02 PM - Re: Grinding plastic #7

    Yeah slow speed and short bursts any friction is going to produce heat so keep it to a minimum, time consuming but there you go.
  8. RICHIES ARMOR's Avatar
    Member Since
    Nov 2001
    From
    Oklahomaaaaaa!!!!!
    Messages
    739
    Dec 15, 2007, 12:37 PM - Re: Grinding plastic #8

    If you have access to a lathe you can easily make grooves etc in PVC without much melting.

    Richie
  9. Member Since
    Dec 2007
    Messages
    36
    Dec 15, 2007, 1:49 PM - Re: Grinding plastic #9

    Thank you very much. I really don't want to get burned by globs of melted plastic.
  10. Treadwell's Avatar
    Member Since
    Aug 1999
    Messages
    16,305
    Dec 15, 2007, 1:56 PM - Re: Grinding plastic #10

    PVC doesn't melt THAT readily. You can grind away. Most you'll get are some tiny rounded melted blobs along the cut edge; no worse than the burrs that will have to be sanded down anyway.

    The drilling halfway thing isn't really necessary, either...PVC is strong enough to endure being riddled with holes--it's not like a blaster barrel is put under any weight or pressure.
  11. Member Since
    Dec 2007
    Messages
    36
    Dec 15, 2007, 2:01 PM - Re: Grinding plastic #11

    Thanks for the information.

    I was planning to either cut or grind some pvc pipe or abs.
  12. motman241's Avatar
    Member Since
    Feb 2003
    Messages
    1,074
    Dec 15, 2007, 3:19 PM - Re: Grinding plastic #12

    I'll second what Treadwell said - PVC and plexiglass don't really melt all that easy. It does depend on what bits you use, though, and how long you keep it in that one spot.

    You will really want some bit that gets the plastic up and out of the way. You'll be throwing a lot of plastic bits around, and they are a bit hot, but nothing to worry about if you are properly dressed and have the normal safety gear on.
  13. RPF Premium Member voice in the crowd's Avatar
    Member Since
    Apr 2005
    From
    Edinburgh, Scotland
    Messages
    1,938
    Dec 15, 2007, 3:46 PM - Re: Grinding plastic #13

    Plastic grinds ok just be aware it may not melt but it still gets hot. When I ground plastic it was on a grinding wheel and it was very messy the spray that came off.

    I would wear rigger gloves to protect your hands.

    Safety goggles are a must. If you have eye protection you are ready to go.

    Cheers Chris
  14. Member Since
    Dec 2007
    Messages
    36
    Dec 15, 2007, 4:12 PM - Re: Grinding plastic #14

    Thanks.
  15. Member Since
    Dec 2007
    Messages
    101
    Dec 15, 2007, 4:27 PM - Re: Grinding plastic #15

    for plastics i usually use a coarser bit, like those long spiraled drywall router cut out bits (more actual cutting and less friction that you would get from a sanding bit) on low to medium speed, but when plastic does melt, the melted stuff is usually a lot weaker and is barely attatched to the original piece, after a second or 2 i usually just snap the melted blobs with my fingers
  16. RPF Premium Member Darth Mawr's Avatar
    Member Since
    Apr 2005
    From
    Birmingham, AL
    Messages
    1,002
    Dec 15, 2007, 4:28 PM - Re: Grinding plastic #16

    I have taken PVC pipe and slid it onto a large wooden dowel and then screwed it in place to the dowel. I then chucked the entire lot into a lathe and was able to accurately turn notches around the circumference of the PVC. Depth depends on what PVC pipe is used.
  17. Member Since
    Dec 2007
    Messages
    36
    Dec 15, 2007, 4:33 PM - Re: Grinding plastic #17

    Thanks.

    Any ideas on how to cut a lengthwise groove across a pvc pipe? I want to run a bit straight across and smoothly.
  18. RPF Premium Member Goldenrod's Avatar
    Member Since
    Apr 2003
    From
    deserts of tatooine
    Messages
    2,610
    Dec 15, 2007, 9:24 PM - Re: Grinding plastic #18

    And throw on a long sleeve shirt and long pants. You'll know why if you don't
  19. Sluis Van Shipyards's Avatar
    Member Since
    Jul 1999
    From
    Miamisburg, OH (near Dayton)
    Messages
    13,711
    Dec 15, 2007, 10:48 PM - Re: Grinding plastic #19

    Nevermind, thought you said cutting, not grinding.
  20. NOT A PREMIUM MEMBER RPF Premium Member stapleton13's Avatar
    Member Since
    Aug 2007
    From
    FT Collins, Colorado, USA, Sector 001
    Messages
    368
    Dec 16, 2007, 12:44 AM - Re: Grinding plastic #20

    Something else that works well is if you have access to a dremel with a flexable shaft. You can do your routing in water. I have used this method for styrene and plexi many times. Its important to use a flex shaft for safty. You don't want your dremel in the water.
  21. sabergirl's Avatar
    Member Since
    Dec 2007
    From
    Bay Area
    Messages
    46
    Dec 16, 2007, 2:05 AM - Re: Grinding plastic #21

    You can submerge the flex-shaft in water, really?! I never knew that...
    Last edited by sabergirl; Dec 16, 2007 at 2:06 AM. Reason: spelling
  22. NOT A PREMIUM MEMBER RPF Premium Member stapleton13's Avatar
    Member Since
    Aug 2007
    From
    FT Collins, Colorado, USA, Sector 001
    Messages
    368
    Dec 16, 2007, 9:18 AM - Re: Grinding plastic #22

    sabergirl said: View Post
    You can submerge the flex-shaft in water, really?! I never knew that...
    I wouldn't submerge it, but when your cutting with the bit in the water you get a lot of splashback on the tool. That could really damage you or your dremel if it was splashing on a motor. Usually when your done all you need to do is whipe the shaft off, and maybe a little lube at the end to prevent problems in the bushing.

Similar Threads

  1. Plastic Sheets, Which Plastic to use
    archtk, General Modeling
    Replies: 4
    Last Post: May 16, 2012, 1:07 AM
  2. grinding a knife's edge, best way?
    LeMarchand, Replica Props
    Replies: 7
    Last Post: Mar 20, 2011, 11:46 AM
  3. Polymorph Plastic
    Roughneckone, Replica Props
    Replies: 2
    Last Post: Aug 12, 2010, 1:14 AM
  4. Question about grinding stainless steel...
    Hecubus114, Replica Props
    Replies: 7
    Last Post: Feb 11, 2010, 11:25 PM
  5. Replies: 8
    Last Post: May 11, 2008, 11:22 AM