More CNC Basics for Aluminum

      Basic advice on cutting aluminum on CNC equipment. December 27, 2006

I'm pretty new to the CNC world - only been doing it for a little over a month. I'm working on a Komo Mach 1 with RouterCIM that my company recently purchased. I've gotten pretty familiar with it, using it mainly to CNC plywood, acrylic, PVC and the occasional aluminum. The only aluminum I've done thus far has been 1/6" thick stuff used in laminating. After a couple of tries, I was able to successfully run the job and have it look flawless... However, what I'm facing now is a little different. This new job consists of 1/4" diamond plate aluminum (unsure of grade). I plan on using a 3/8" downcut spiral O-flute solid carbide bit (Onsrud # 64-031), as this is the only bit I have available at the moment that is rated for aluminum.

Would it be a good idea to run this diamond plate in two or more passes or just one? What should I use to spray the tool in order to avoid overheating? Does my feed/rpm sound right? 12,000-13,000 rpm/150-200 feed rate?

Forum Responses
(CNC Forum)
From contributor D:
What are you doing? A through cut? A design milled in the surface? I would, myself, slow feed speed way down and make many very shallow passes, .005 or less, per pass. Though I could be way off.

From the original questioner:
Sorry for being vague... What I'm actually doing is a through cut logo (text).

From contributor W:
For 1/4" thick aluminum, I would suggest two rough passes and one finish pass. Always run the tool in the climb cutting direction, and coolant always helps. You will have to play with feed speeds to get the edge quality you need. Personally, I would use an upcut bit.

From contributor R:
Your tooling vendor should be able to tell you what feeds and speeds to use. Also, you will need to spray coolant on the tool while machining. Your tooling vendor should be able to give you some recommendations there as well. It would also be a good idea to talk with the folks at Komo.

From contributor G:
I would not use a down shear tool, as it will gum up. Use a straight or up shear tool, as you need the chips to come out of the cut. Both tools are for dry cutting.

From contributor T:
I hate to come in with a differing theory, but here goes. You should be using a solid carbide endmill for this application. Your depth of cut should not exceed one diameter of your cutting bit per pass. Endmills are always down cutting, as it helps to eliminate burs on the top surfaces.

Aluminum diamond plate is one of the harder grades of aluminum. It is used a great deal on running boards and other tough applications.

Based on this information, you can run this application at 12,000 RPM's and 76 inches per minute feed rate. This is a starting feed rate you can adjust up to increase production or down to improve finish quality.

As for coolant, if you want non-messy options, try stick wax or a cold air gun. If mess isn't an issue, most metalworking coolants will work, but some are made for non-ferrous metals as they will not stain the part.

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 © 1996-2018 - 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