Mortising Sharp Inside Corners on CNC Equipment

      A few suggestions for making inside corner cuts with a CNC machine. April 6, 2007

Question
Often I am asked to cut grilles or grids from MDF or solid wood, the criteria being that the corners are as small a radius as can be so that the hole would resemble more of a square. I perform this task on a CNC router using a 1/8" spiral making one to two passes to complete the cutout. Because the tool is so small, I have to use a slow feed rate to keep from breaking the tool. Does anyone have recommendations on how to do this better?

Forum Responses
(CNC Forum)
From contributor F:
Why don't you cut the slot with a larger diameter tool, then come back with the small tool to just to clean out the corners? On some details, I come back in with a 1/16" diameter bit to do the cleaning out. Better than a chisel.



From contributor W:
I agree with contributor F. If you must make the grille out of one piece, I sometimes will dado a piece of wood or MDF on the CNC, then cut into strips on the table saw so they half-lap together. You will get square corners that way; a little bit more time, though.


From contributor M:
A few options depending on the size of the slot and equipment.

1- Drill a small hole in each corner of the slot and then rout it. The drill will provide the small radius, but it is stronger drilling than routing with the small diameter.
2- After routing the slot, drop a saw blade in and square up the corners.
3- There is an aggregate which holds a milling cutter and is commonly used in door cutouts.



Would you like to add information to this article?
Interested in writing or submitting an article?
Have a question about this article?


Have you reviewed the related Knowledge Base areas below?
  • KnowledgeBase: Knowledge Base

  • KnowledgeBase: Computerization

  • KnowledgeBase: Computerization: CNC Machinery and Techniques


    Would you like to add information to this article? ... Click Here

    If you have a question regarding a Knowledge Base article, your best chance at uncovering an answer is to search the entire Knowledge Base for related articles or to post your question at the appropriate WOODWEB Forum. Before posting your message, be sure to
    review our Forum Guidelines.

    Questions entered in the Knowledge Base Article comment form will not generate responses! A list of WOODWEB Forums can be found at WOODWEB's Site Map.

    When you post your question at the Forum, be sure to include references to the Knowledge Base article that inspired your question. The more information you provide with your question, the better your chances are of receiving responses.

    Return to beginning of article.



    Refer a Friend || Read This Important Information || Site Map || Privacy Policy || Site User Agreement

    Letters, questions or comments? E-Mail us and let us know what you think. Be sure to review our Frequently Asked Questions page.

    Contact us to discuss advertising or to report problems with this site.

    To report a problem, send an e-mail to our Webmaster

    Copyright © 1996-2016 - WOODWEB ® Inc.
    All rights reserved. No part of this publication may be reproduced in any manner without permission of the Editor.
    Review WOODWEB's Copyright Policy.

    The editors, writers, and staff at WOODWEB try to promote safe practices. What is safe for one woodworker under certain conditions may not be safe for others in different circumstances. Readers should undertake the use of materials and methods discussed at WOODWEB after considerate evaluation, and at their own risk.

    WOODWEB, Inc.
    335 Bedell Road
    Montrose, PA 18801

    Contact WOODWEB











  • WOODWEB - the leading resource for professional woodworkers


      Home » Knowledge Base » Knowledge Base Article