The other option of course is just to toss out the motor and switch to say the 130SM-M1525MAL from Bergerda rated at 3.8kW (divided by 750W/HP) is 5HP at 2500 RPM. Runs off 220VAC 13.5A circuit. With the 2500 line encoder can do step/dir as slow as you want although at really slow RPM the torque does drop off a little bit. http://www.autoartisans.com/MotorDrives/130SeriesACServoMotor.pdf
I'm running a smaller version on my mill the 110AM-M0630MAL which is 1.8kW at 3000 RPM http://www.autoartisans.com/MotorDrives/110SeriesACServoMotor.pdf I had it stall once with 1:1 on the mill when breaking through 1/4" steel place with a 1/2" drill bit. I think I was running 100RPM and the flutes caught and the motor faulted as the drill bit locked tight as it broke through. Changed up to 300 RPM for the rest of the holes without an issue but it may have broken through differently at that RPM too. I do wonder if there's a bit of Sears Horse Power going on here too since 220VAC * 6A for my motor works out to 1320W which is only 1.76HP and the motor is rated as 1.8kW. But then the motor is also significantly smaller (and quieter) than the 2HP single phase heavy cast iron unit it replaced. In either case, I'm really happy with this motor and drive from Bergerda http://en.bergerda.com/ I currently have a 3 phase 1HP with VFD on my lathe but if I need really slow RPM I still switch in the back gear. Otherwise with the lowest belt speed and the VFD I haven't had problems. But for my mill a 3 phase 2HP motor, VFD and shipping costs were more expensive than the Bergerda. John > -----Original Message----- > From: andy pugh [mailto:bodge...@gmail.com] > Sent: July-28-21 2:34 AM > To: Enhanced Machine Controller (EMC) > Subject: Re: [Emc-users] Lathe Spindle Drive Questions > > On Wed, 28 Jul 2021 at 00:46, Gene Heskett <ghesk...@shentel.net> wrote: > > > > Yes, this is an approx. 1984 machine. > > > > That new? I would have guessed 1934, the year I was born. That means of > > making a variable speed motor is ancient tech because its not very > > efficient. > > I think you are maybe thinking of the Ward Leonard set, as used on the > early Monarch 10EE, where an AC motor ran a DC generator which, in > turn ran a DC motor. > That is pretty old-tech, but a DC motor with solid state drive is > hardly old-school at all (only the use of field coils is slightly > outdated at that motor size) > > > An AC motor and a vfd should cut the energy bill in half > > compared to that. > > But will have less low-speed torque. Bear in mind that the lathe is > geared for 2500rpm and was probably running at 250rpm (steel part 8" > dia, carbide tooling) > A VFD would be down at 5Hz to achieve that. > > I think that a DC motor is appropriate here, but probably a PM servo > motor would be better. > > Is this the motor originally supplied with the lathe? > > -- > 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, 1912 > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
