On Tue, Jun 25, 2019 at 7:34 AM andy pugh <[email protected]> wrote:
> On Tue, 25 Jun 2019 at 14:27, Gene Heskett <[email protected]> wrote: > > > Absolutely. And in the ER32's turning 3G's max in my G0704's abused > > spindle, balance is not a prime concern, but in an ER20 where you expect > > to hit perhaps 15k revs, or in my 6040 with its ER11 turning 24k, a few > > milligrams can destroy the motors bearings eventually. > > An ER16 nut is 22mm dia. > > Centrifugal[1] force is MR(omega)^2. > 24k rpm = 2513 rad/sec > So the bearing force on a 24k rpm ER16 is 138N / g. > How unbalanced are the nuts typically? 138N/g is not bad if the nuts are balanced to 1 milligram. Also you calculation overstates the force because all the mass is not at the outside shell of the nut. The mass is distributed throughout the steel How do tire balance machines work? Seems if there were an issue you can just the nut for balance > > To put that in perspective, FSWizard suggests settings that give a 30N > cutting force on a 3mm cuttter. > I expect that the oscillatory nature of the centrifugal force gives > the bearings a harder time too. > > [1] I have a physics degree, I am licensed to use centrifugal > force[2]. Do not try this at home. > [2] www.xkcd.com/123 > > -- > atp > "A motorcycle is a bicycle with a pandemonium attachment and is > designed for the especial use of mechanical geniuses, daredevils and > lunatics." > — George Fitch, Atlanta Constitution Newspaper, 1916 > > > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > -- Chris Albertson Redondo Beach, California _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
