Re: Best Al cutting solution..

On Mon, 10 Jul 2006 21:25:45 GMT, Anthony <tonytn36sp@xxxxxxxxxxx>
wrote:


Bryce,
The grade of PCD will have an effect on the finish. For roughing or
normal machining, a coarse grade is better, as the larger diamond
particles last longer. But, with larger diamond particles, the binding
agent breaks down at the cutting edge between the diamond crystals,
leaving a rougher surface finish. A smaller (finer) crystal size will
help this considerably. Check with GE and Debeers for a fine-crystal PCD
blank. This may be the reason TFD is outperforming the PCD in this
application. Edge prep on the diamond also makes a difference. Relief
angle plays a major role also.
That's an itsy-bitsy radius for trying to get a mirror finish. If you can
get to the part with something along the lines of a 0.120" radius you
could speed up your feeds considerably and maintain the finish. It will
impart a bit more load into the cut as your surface contact area is
larger.

Unfortunately, our part geometry barely lends itself to 1/32" radius.
These are screw machine parts, dontchaknow (.650" part OD). Our
failure indication is actually a chatter problem, which even with a
new insert, is evident at our current feedrates if we take a lighter
or a heavier depth of cut. Just had to play around for awhile, but
everything is working great now.

Thanks for steering us that way, we are now using both types for
turning as well as boring applications, with outstanding results.


Your welcome. I just try to help.

I'll also bet you don't make many (if any) adjustments during a run
either. Consistency is it's other enduring trait.

Only for temperature, which depends on which axes of our swiss
machines we are using to position the tool (or part). The longer the
axis travel, the more temperature changes become a factor. We're in a
new building with a much bigger shop recently, and the ambient
temperature doesn't change as much. :-)

--
Bryce

----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----
.

Relevant Pages

  • Re: Best Al cutting solution..
    ... Bryce wrote in ... starting at .375" diameter and going to .650" diameter, ... some type) from SP3 Diamond Cutting Tools, and we have had much better ... The grade of PCD will have an effect on the finish. ...
    (alt.machines.cnc)
  • Re: tool grinding
    ... green or diamond wheels on steel. ... well/long machining steel. ... Biggest single tip is to keep your wheels "dressed" so they will ...
    (rec.crafts.metalworking)
  • Re: Best Al cutting solution..
    ... Polycrystaline Diamond (PCD) literaly ... means many crystals. ... variety of feedrates, but out of curiousity, with a standard wiper is ...
    (alt.machines.cnc)
  • Re: Optimum particle size
    ... > The particles are hard and inert such as SiC or diamond. ... > successfully rolled 1 mil foils with 2-3 micron particles but I want to ... Metallization of diamond is SOP for heatsinks. ...
    (sci.materials)
  • Re: modern marvels, aluminum
    ... Could have been PCD, but it looked more like a natural diamond, or a ... monocrystalline synthetic to my trained eyes and years of working with PCD, ... softer than the diamond particles. ...
    (rec.crafts.metalworking)