Mortising Sharp Inside Corners on CNC Equipment
A few suggestions for making inside corner cuts with a CNC machine. April 6, 2007
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?
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: CNC Machinery and Techniques
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.
335 Bedell Road
Montrose, PA 18801
Copyright © 1996-2016 - WOODWEB ® Inc.