Drag Knife for CNC [Pics+Video]

Results 1 to 18 of 18

Thread: Drag Knife for CNC [Pics+Video]

  1. #1
    Registered Grunblau's Avatar
    Join Date
    Jun 2008
    Location
    Michigan, USA
    Posts
    201
    Downloads
    0
    Uploads
    0

    Default Drag Knife for CNC [Pics+Video]

    I decided to try to make a drag knife for my CNC. In architecture school, we were constantly making models out of museum board and chip board. I wish I had one of these back then!

    I know that there are examples of utility drag knives on the 'Zone going back before 2003, but I didn't pay too much attention as the real trick is the G-code. The knife needs to be reoriented at each corner as well as a slight compensation on curves. Imagine taking a turn while pulling a trailer since the blade is trailing the center of the tool... There are also commercial drag knives available, but for almost $250 I decided to DIY one instead.

    Fortunately, ten years later there is also now plenty of software out there that can do the compensation. I do not have this software yet, so I asked some of the other Platform owners to help me out with the g-code. David Hill came through with not only the gcode, but also the geometry for the tests!

    Here is an image of the first prototype knife...




    What it looked like assembled...




    From this, I realized that the front part of the blade should be vertical to aide in the rudder effect... This meant that I should look at how to orient the blade for better results.

    This concept came to me while I was milling another test out of acrylic....





    Looks great, but I never tried it before I cut the most recent one out of aluminum.


    Here is the assembly...




    Fully assembled, ready to test!




    So, does it work?

    Guess you'll have to watch the video!

    <iframe width="640" height="360" src="//www.youtube.com/embed/YqvgA1P5hWg" frameborder="0" allowfullscreen></iframe>

    Happy Holiday Tinkering!

    -Brian

    Similar Threads:


  2. #2
    Registered
    Join Date
    Jan 2008
    Location
    Ca
    Posts
    199
    Downloads
    0
    Uploads
    0

    Default

    Nice work!
    I love it when one can take a thought to a concept to the real thing!

    Great job!

    My Build: http://www.cnczone.com/forums/diy-cnc_router_table_machines/113711-my_build_-_many_thanks.html


  3. #3
    Registered landarts's Avatar
    Join Date
    Aug 2004
    Location
    united states
    Posts
    107
    Downloads
    0
    Uploads
    0

    Default

    Hey great work on the drag knife. Are you going to be selling them? Please let me know if you are.



  4. #4
    Registered baskarz's Avatar
    Join Date
    Nov 2012
    Location
    Australia
    Posts
    43
    Downloads
    0
    Uploads
    0

    Default

    very neat little tool!
    would you be willing to share the dxf?



  5. #5
    Registered
    Join Date
    Dec 2013
    Posts
    41
    Downloads
    0
    Uploads
    0

    Default

    Wow! Another great design! Way to go! Would love to build one of these (once my cnc is built).



  6. #6
    Registered
    Join Date
    Dec 2012
    Location
    USA
    Posts
    15
    Downloads
    0
    Uploads
    0

    Default

    Looks Great, Nice Design.

    Would you mind sharing the information from David Hill? What did he do for the came through with geometry tests!

    Also Vetric Aspire now does drag knife integration for the G code side of things.



  7. #7
    Registered
    Join Date
    Jan 2010
    Location
    USA
    Posts
    30
    Downloads
    0
    Uploads
    0

    Default Re: Drag Knife for CNC [Pics+Video]

    I made some modifications (just cuz I could, not because they were needed) of GrunBlau's drag knife and here is the result. This was my first time cutting aluminum, so I've still a lot to learn.

    Drag Knife for CNC [Pics+Video]-drag-knife-jpg



  8. #8
    Registered
    Join Date
    Jul 2006
    Location
    US
    Posts
    137
    Downloads
    0
    Uploads
    0

    Default Re: Drag Knife for CNC [Pics+Video]

    What S&F did you use with the onsrud 1/4 oflute? and the 1/8 2-flute?

    What did you mean by "onion" when talking about the tabs?



  9. #9
    Registered briankb's Avatar
    Join Date
    Sep 2012
    Location
    United States
    Posts
    13
    Downloads
    0
    Uploads
    0

    Default Re: Drag Knife for CNC [Pics+Video]

    looks a lot like the one from Donek Tools, they sale them if you want to buy something ready to use. I believe they also have related software for the dragknife.

    Purchase A D1 Drag Knife - Donek ToolsDonek Tools

    here is their youtube channel https://www.youtube.com/user/DonekTools/videos

    They also have a crease add-on to make custom boxes.



  10. #10
    Registered WASNAPYRO77's Avatar
    Join Date
    Apr 2015
    Posts
    7
    Downloads
    2
    Uploads
    0

    Default Re: Drag Knife for CNC [Pics+Video]

    Drag Knife
    I have a problem using my CNC with the Aspire Program.
    I have been watching all the tutorials and reading all the comments but my drag knife doesn't turn with the lines and get broken. I follow all the steps and the problem still be there.
    How can I control the elevation of the drag knife in Z ,for change the lines, because in the Aspire program I couldn't find the Z's set up?
    I will appriciated the help, and if somebody knows how fix it, please send me screen shoots, pictures or videos for how you set up the elevation of the drag knife in Z.
    Thank you very much!
    Maximiliano



  11. #11
    Registered
    Join Date
    Dec 2012
    Location
    USA
    Posts
    15
    Downloads
    0
    Uploads
    0

    Default Re: Drag Knife for CNC [Pics+Video]

    I made one a year ago.

    but I never got around to trying to make it work. I did not have a good way to write the g code for the drag knife itself.

    So there it sits.



  12. #12
    Registered
    Join Date
    Jan 2013
    Location
    Australia
    Posts
    2
    Downloads
    0
    Uploads
    0

    Default Re: Drag Knife for CNC [Pics+Video]

    Quote Originally Posted by WASNAPYRO77 View Post
    Drag Knife
    I have a problem using my CNC with the Aspire Program.
    I have been watching all the tutorials and reading all the comments but my drag knife doesn't turn with the lines and get broken. I follow all the steps and the problem still be there.
    How can I control the elevation of the drag knife in Z ,for change the lines, because in the Aspire program I couldn't find the Z's set up?
    I will appriciated the help, and if somebody knows how fix it, please send me screen shoots, pictures or videos for how you set up the elevation of the drag knife in Z.
    Thank you very much!
    Maximiliano
    There is a Dragknife Gadget for Aspire, check here: Vectric Gadgets



  13. #13
    Registered
    Join Date
    Mar 2011
    Location
    USA
    Posts
    22
    Downloads
    0
    Uploads
    0

    Default Re: Drag Knife for CNC [Pics+Video]

    I see Tormach has a drag knife mill tool.

    32440 - Spring-Loaded CNC Drag Knife



  14. #14
    Registered
    Join Date
    Mar 2013
    Location
    libanon
    Posts
    2
    Downloads
    0
    Uploads
    0

    Default Re: Drag Knife for CNC [Pics+Video]

    Pls dxf file for acrylic knife??



  15. #15
    Member msimpson99's Avatar
    Join Date
    Aug 2010
    Location
    USA
    Posts
    684
    Downloads
    0
    Uploads
    0

    Default Re: Drag Knife for CNC [Pics+Video]

    The Tormach drag knife is actually a WidgetWorks drag knife. Which can be purchased here as well:
    Sign Vinyl Drag Knife Bit - Use Your CNC Machine to Cut Vinyl Stickers and Lettering, Paper, Cardboard, and Plastic - WidgetWorks Unlimited

    I have one of these and while they are great for very thin materials, they will not work on thicker materials like cardboard.

    Author of: The CNC Construction Set Books, the KRMx01, KRMx02, KRmc01, and KRmf70 CNC Books, the HANS Electric gear clock book. All available at www.kronosrobotics.com.


  16. #16
    Member msimpson99's Avatar
    Join Date
    Aug 2010
    Location
    USA
    Posts
    684
    Downloads
    0
    Uploads
    0

    Default Re: Drag Knife for CNC [Pics+Video]

    I just did a writeup on my building of the Grunblau drag knife.
    You can find it here:
    Making a Grunblau Drag Knife — Kronos Robotics

    Author of: The CNC Construction Set Books, the KRMx01, KRMx02, KRmc01, and KRmf70 CNC Books, the HANS Electric gear clock book. All available at www.kronosrobotics.com.


  17. #17
    Member
    Join Date
    May 2016
    Location
    United States
    Posts
    34
    Downloads
    0
    Uploads
    0

    Default Re: Drag Knife for CNC [Pics+Video]

    Thank you for this write-up. Great job!



  18. #18
    Member
    Join Date
    Oct 2007
    Location
    canada
    Posts
    431
    Downloads
    0
    Uploads
    0

    Default Re: Drag Knife for CNC [Pics+Video]

    Hi,

    Are you making the aluminum version of the drag knife? Interested in purchasing.

    thanks
    Jeff



Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  


About CNCzone.com

    We are the largest and most active discussion forum for manufacturing industry. The site is 100% free to join and use, so join today!

Follow us on


Our Brands

Drag Knife for CNC [Pics+Video]

Drag Knife for CNC [Pics+Video]

Drag Knife for CNC [Pics+Video]