On Fri, 2014-11-07 at 12:24 +0000, andy pugh wrote: > On 7 November 2014 11:55, Marshland Engineering > <[email protected]> wrote: > > so 10-20 watts would be enough. Why does my Anilam lathe and SWI mill use 2 > > kw > > motors ? > > It is probably to get the steady-state constant torque rating required > for the cutting forces. > > Lets consider a cut with the max cutter that the spec says (32mm) > making a 6mm deep slot. > http://zero-divide.net/?page=fswizard calculates cutting forces. > That suggests 450 rpm, 172mm/min feed and 1800N cutting force. > That is still only 5W of power required, but the ball-screw torque is > now 9.0 Nm (1300 oz-in) and suddenly your motors look undersized. > (you should be able to make the cut at 3mm DOC and a slower feed, though) > IIUC cast to cast friction chews up a lot of power. My small mill is somewhat like a BP. SEM MT30H servo motors at about 100 v.
http://igor.chudov.com/projects/Bridgeport-Series-II-Interact-2-CNC-Mill/_Manuals/SEM-MT_Technical_Data_Manual.pdf I used to drive them with 165 vdc and Servo Dynamics BR-1525 amps. Max speeds were in the range of 100 ipm. I now have backed off and use a 100 vdc source and it is very comfortable at 30 ipm. I intend to change the gearing to see if I can get a bit more speed but that means a major change in driving the X axis. Haven't found a roundtoit for that task. On the other hand the Mazak V5 with similar motors and 10X the mass but the same power supply and polymer ways will do 400 ipm with ease. HTH Dave ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
