Gene, I definitely agree if I could spin the bits faster I could reduce tear out.
The only thing that I though might work (to get better rpm's with tiny bits) is to use one of those brushless DC RC airplane motors. Some of them run up to 55-60k rpm. I think I might try this. Running a compressor to drive an air tool is not practical for me. BTW, Those tiny little router bits are too fragile. I find a much more durable solution is to grind a carbide blank to a sharp point. Then grind half the point away from the side. Splitting the cone lengthwise, so to speak. I do this with the blank chucked in the lathe and a diamond wheel on a tool post grinder. Takes some time to do initially but not as long as I thought it would, plus resharpening takes only moments. ----- Original Message ----- From: "Roland" <[EMAIL PROTECTED]> To: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net> Sent: Wednesday, March 28, 2007 6:31 PM Subject: Re: [Emc-users] Show us your pics of unobtanium! > At 10:35 AM 28/03/2007 -0400, you wrote: > > >>over half an hour per pass though. MCS is selling a little air grinder >>rated at 70k rpms, I wonder how that might work mounted on the side of >>the head on my micromill for something like that? Has anyone here >>attempted something along those lines? >> > > When I was working on the Emco mill, 1mm carbide bits had a short, costly > life, so we wanted to try using tungsten dental bits. This was for > metal-work, doing fine work on brass patterns for spin casting. > > We ran some straight line test cuts in steel with a mock up, and it seemed > ok, so we removed the milling head entirely and mounted a Pferd air-tool. > Firstly, the air consumption had a fair size compressor running at 50%. > Then we found that the spindle on the air-tool is not rigid enough. It's > fine when you use it manually, since you 'press' as required, with visual > and audible feedback, as well as being able to tilt the tool for a better > scallop, but for automated running it was a disaster. Especially in > cavities, and cutting 'downhill' it tended to bite and whip, making > horrible squealing noises with a crappy finish. Steel or brass yielded > similar results. We abandoned that idea, but i'd be interested to know if > anyone had more success with a bigger tool. > > Regards > Roland Jollivet ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users