I love it when a plan comes together. Tested out the Bergerda 1.27NM motor on the Y axis. I was worried that it might not carry the extra weight as the DC Servos were 1.6NM.
Well. Silky smooth. For a 2.8A motor it never has more than about 1.0A current draw and about 0.34NM based on what the servo drive reports. Sounds nice too. And that's with two heavy vices and a rotary table all the way up to 3000 RPM 4:1 to 0.2" pitch ACME screw. Time to put the other one on the X axis and verify that the positions remain accurate. John > -----Original Message----- > From: Bari [mailto:bari00...@gmail.com] > Sent: September-18-21 11:30 PM > To: emc-users@lists.sourceforge.net > Subject: Re: [Emc-users] DC Servo issues > > On 9/19/21 00:44, John Dammeyer wrote: > > > Over 10 years ago I bought two of these for the XY axis of the mill. > > https://www.automationtechnologiesinc.com/products-page/dc-servo-motor/nema34-1125ozin-dual-shaft-servo-motor > > > One of the things that showed up right away was that with identical drives > > one motor ran hotter than the other. Further > investigation showed the resistance of the windings was different with the > warmer motor having the lower resistance and > inductance which matched the spec sheet. By then it was too late to return > the high resistance one so I decided to put what > appeared to be the on spec motor on the Y axis since it had to carry more > weight. The X axis got the cooler and higher resistance > motor. > > Especially since AutomationTechnologies wouldn't replace the motor even > > though it was clearly out of spec. Not about to buy > anything else from them. > > > They are local for me. The owner is a nice enough guy but he also > problems with getting reliable consistent parts from his homeland. > > I only buy things from them that I expect to be like a kit that needs to > be cleaned and assembled properly before use. I have had to return > radial bearings with detents and linear bearings with crud inside or > flat spots. We call them crunchy bearings. CNC mills come with red oxide > treated fasteners and without nuts on the end of ballscrews so you can't > adjust preloads unless you shim or replace with proper screws. Cables > are assembled without the use of strain reliefs. > > Red oxide treated fasteners� https://postimg.cc/jnhmsRhq > > No strain relief� https://postimg.cc/7bqwTvvy > > 1mm of lash� https://postimg.cc/w1bvqpWk > > > > > _______________________________________________ > 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
