2017-01-25 14:10 GMT+02:00 Steve from Tube Gauge <[email protected]>:
> Hi: > > I have a CNC mill that I am considering replacing the control with > LinuxCNC. The motors are the red cap Fanuc units. I have enquired on this > mailing list about using the existing servo amps and motors. From all the > replies and help (thank you very much) I haved concluded that a good > solution for me is to remove the Fanuc encoders and amps and replace them > with suitable units that can communicate on an industry standard format. > To that end I am considering using some AMT31 programmable encoders by CUI > (or other encoder suitable for 8 pole motors) and some BE40A8 AMC amps that > I have sitting on my shelf. > > I am aware of the rpm/voltage relationship with brush DC motors. > Generally, as the voltage rises the motor rpm increases a > proportional amount. How does the voltage influence the performance of the > brushless motor? The Fanuc motors are 5S models, 126 V (DC?), 5.8A stall. > The BE40A8 have a maximum running voltage of 80 VDC. Will running the > motors at the lower voltage result in dramatically reduced performance? > Will it cause other electrical problems like an excessive rise in current > demand by the motor? > > AFAIK motor torque at higher rpm will be seriously decreased at lower voltage. I.e. if the nominal is 3000 rpm, you'll have 3000 * 80 / 127 = 1890 rpm max But probably they require 127V for 4500 rpm, then it's better: 4500 * 80 / 127 = 2830 rpm Andrew ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
