On 4 Jul 2015, at 22:50, Gene Heskett wrote: > On Saturday 04 July 2015 14:41:40 Marcus Bowman wrote: >> On 4 Jul 2015, at 01:28, Gene Heskett wrote: >>> On Friday 03 July 2015 20:19:09 Bertho Stultiens wrote: >>>> On 07/04/2015 01:48 AM, Gene Heskett wrote: >>>>>> If we assume a mill with zero backlash and spindle-speed very >>>>>> much larger than the feed-rate, would you still care or be >>>>>> careful about direction? >>>>> >>>>> Call me a picky old fart, >>>> >>>> I would not dare call you picky. >>> >>> Oh? why not? >>> >>>> The other part I have no comment. ;-) >>> >>> I've been called lots worse than that. And I call myself picky >>> because its the best fix for good enough, which too often isn't. >>> >>>>> but yes, direction will show because there is going to be the >>>>> machine and tool flex from the cutting force, miniscule for a 10k >>>>> rpm conical bit. Double that force every time the tool revs get >>>>> cut in half and it will become quite visible. >>>> >>>> Good point. I had not thought about flexing. That will definitely >>>> have a result. >>> >>> Yes, the common 1/8", 60 degree solid carbide engraver can probably >>> flex sideways 30 thou when pushed too fast, before it breaks. >> >> Well I'm using 30 degree (included angle) 1/8" shank carbide cutters >> with a 0.2mm flat on the tip, and they can flex sideways precisely >> zero before the little blighters snap. The 10 degree cutters break >> under a heavy breath, so I have all but given up on those. > > Never tried one that sharp. I did make a bunch of desk nameplates a > couple years ago, in .03125" brass door kick plate. Worked well and > didn't break it, but with my slow (2500 wide open) spindle I was only > feeding 3 ipm or thereabouts. Slow enough I think the brass was work > hardening. They would work better if one could orient them in the collet > so the peak of the spindles TIR and the cutting edge matched. That > would tend to give better heel clearance & a better cut. But that would > be picky indeed to fiddle with that! >
I run 3000rpm at 100mm/min (= 4 inches per minute) in brass or aluminium. With a 30 degree (included angle) cutter that works reliably and the cutters have a high survival rate. So our rates are similar, taking the extra revs into account. >> Marcus >> >>>> Flexing could also be a visible problem if you retrace a path. But >>>> it would depend very much on feed-rate and speed. >>> >>> Cheers, Gene Heskett >>> -- >>> "There are four boxes to be used in defense of liberty: >>> soap, ballot, jury, and ammo. Please use in that order." >>> -Ed Howdershelt (Author) >>> Genes Web page <http://geneslinuxbox.net:6309/gene> >>> >>> -------------------------------------------------------------------- >>> ---------- Don't Limit Your Business. Reach for the Cloud. >>> GigeNET's Cloud Solutions provide you with the tools and support >>> that you need to offload your IT needs and focus on growing your >>> business. Configured For All Businesses. Start Your Cloud Today. >>> https://www.gigenetcloud.com/ >>> _______________________________________________ >>> Emc-users mailing list >>> Emc-users@lists.sourceforge.net >>> https://lists.sourceforge.net/lists/listinfo/emc-users >> >> ---------------------------------------------------------------------- >> -------- Don't Limit Your Business. Reach for the Cloud. >> GigeNET's Cloud Solutions provide you with the tools and support that >> you need to offload your IT needs and focus on growing your business. >> Configured For All Businesses. Start Your Cloud Today. >> https://www.gigenetcloud.com/ >> _______________________________________________ >> Emc-users mailing list >> Emc-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/emc-users > > Cheers, Gene Heskett > -- > "There are four boxes to be used in defense of liberty: > soap, ballot, jury, and ammo. Please use in that order." > -Ed Howdershelt (Author) > Genes Web page <http://geneslinuxbox.net:6309/gene> > > ------------------------------------------------------------------------------ > Don't Limit Your Business. Reach for the Cloud. > GigeNET's Cloud Solutions provide you with the tools and support that > you need to offload your IT needs and focus on growing your business. > Configured For All Businesses. Start Your Cloud Today. > https://www.gigenetcloud.com/ > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ Don't Limit Your Business. Reach for the Cloud. GigeNET's Cloud Solutions provide you with the tools and support that you need to offload your IT needs and focus on growing your business. Configured For All Businesses. Start Your Cloud Today. https://www.gigenetcloud.com/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
