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 [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
