Welcome To Signs101.com: Largest Forum for Signmaking Professionals

Signs101.com: Largest Forum for Signmaking Professionals is the LARGEST online community & discussion forum for professional sign-makers and graphic designers.


  1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

What bit should i use to cut corrugated plastic on cnc?

Discussion in 'CNC Routers & Engravers' started by 0igo, May 15, 2020.

  1. 0igo

    0igo Active Member

    Mar 22, 2014
    Stockton Ca
    Does anyone with a cnc know if its possible to get clean cuts out of corrugated plastic on a cnc machine? i cut it using an spiral upbit and it left the edges ugly. maybe i went to fast? is there a bit that you guys have used that works?
  2. JBurton

    JBurton Signtologist

    Sep 28, 2017
    If I remember correctly, you want to go the opposite direction than what the bit manufacturer recommends. Try cutting a straight line and see if one side cuts cleaner than the other. I run a 1/8" belin single flute upcut on almost everything, but it leaves trash on the coro edges too.
    Ideally you get a tangential knife attachment and it will give perfect cuts.
    • Like Like x 2
  3. Raum Divarco

    Raum Divarco Application Specialist CWT / Amcad & Graphics

    Feb 23, 2017
    while is generally is better to cut with an oscillating tool, there are router bits for honeycomb materials etc. that are applications for straight flute tooling.
    you might also want to look into more cnc endmills that have many small teeth.
    you might find limitations depending on shank size etc.
    • Like Like x 1
  4. ikarasu

    ikarasu Very Active Member

    Jun 10, 2016
    Port Coquitlam, bc
    The flutes are thin plastic that just get pushed around.... We've never had luck cutting it perfect with our router. Even the drag knife does the same thing in certain spots.

    We have a soldering iron we run across the edges that look bad.... The plastic is so thin it just melts off. It's been the easiest way we can find to clean it.
    • Like Like x 2
  5. 0igo

    0igo Active Member

    Mar 22, 2014
    Stockton Ca
    Thank you for this I almost bought that knife tool...they’re expensive also lol. Luckily I’m just cutting out a big outline of my sons face so I guess I’ll just clean the edges.
  6. zspace

    zspace Merchant Member

    Jul 9, 2013
    Houston, TX
    We haven’t found a router bit that cuts coroplast well. Reciprocating knives are the way to go for CNC. If you don’t have one,then for a short run you would do better hand cutting with an exacto knife. For a large run outsource it.
    • Agree Agree x 1
  7. MoultrieMade

    MoultrieMade Member

    Jul 15, 2017
    Moultrie, GA
    I have had good results using a Donek drag knife with X-acto blades for 3mm coro. I edit my cut file to soften any inside corners. This eliminates the need for the knife to raise up in Z to make a sharp turn. I do the same for outside corners, or add loops if I want them to stay sharp. I'm generating my tool path with the drag knife gadget in Vectric Aspire.

    I've only done a few jobs with 6mm+ coro, but a 1/4" O-flute bit seemed to give the best results there. The corrugations were heavy enough for the bit to cut them rather than fold them over like it does in the 3mm material.
  8. johnnysigns

    johnnysigns Very Active Member

    Nov 3, 2004
    East Coast
    Higher feed rates seems to help on coro. A new sharp tool also really helps. I can dig up feed rates we've used from our CNC if you need a baseline.
  9. Reveal1

    Reveal1 Active Member

    Nov 7, 2010
    Cape Girardeau, MO
    Looks like you lost a few fingers on the router there 0igo.
  10. White Haus

    White Haus Formally known as RJPW..........

    Apr 6, 2018
    Would love to check it out if you get a chance to dig this up. Thanks!
  11. johnnysigns

    johnnysigns Very Active Member

    Nov 3, 2004
    East Coast
    We use these speeds at different depths for either perimeter/through cuts or scores for folding at a lesser depth. I believe I got some of this info many years ago on here from Typestries who was nice enough to share it. If you're comfortable with your machine moving at faster feed rates you can scale the RPM up to match. We use a simple feed rate calculator I downloaded online somewhere. I'm sure if you google: cnc feed rate exe some links should pop up to grab one.

    0.250" Tool Single Flute Upcut
    10500 RPM at 400 IPM with a plunge of 100 IPM
  12. Christian @ 2CT Media

    Christian @ 2CT Media Major Contributor

    Jun 15, 2009
    Mesa, Arizona
    Compression bits work well as long as the compression is in the gap.