Here is a discussion about inertial mismatch. http://www.motioncontrolonline.org/content-detail.cfm/Motion-Control-Technical-Features/Understanding-the-Mysteries-of-Inertia-Mismatch/content_id/404
The Sizing software that Automation Direct has on their website can be used to check motor sizing for non-Automation Direct motors. I have used it for years and it has never missed. Run the calculations and see how well they matched your original motors. That will give you an idea if you can get by with 1/2 of the original motor inertia. Dave On 4/4/2017 2:35 PM, robert - Innovative-RC wrote: > Hi > > i am planning to retrofit a machine i will change the servo motors as > current ones are faulty etc.... > anyways i know the motor ratings on the machine right now as follows > > Yaskawa USAFED-30FS20E > Rated 18.6Nm > Continuou Max 22.5Nm > Peak max 54.1Nm > Rated Speed 1500rpm > Max Speed 2000rpm > Torque Constant 0.98Nm/A > Moment of Inertia jm(=GD2/4) 110.0kg.m2x10-4 > Power 2.9Kw > > now the servo i was looking at replacing with has the same torques but a > lower Inertia Jm value. what effects does this have on the > accell/deaccel , i know motor it self takes less toque to accel its > self.. but how does this related back to the load wanting to carry on > moving when trying to deaccel it, what are the the realworld or other > impacts on the motor/drive , am i more likly to see higher bus > voltage/regen problems from the motor loading, as this motor is on a Z > axis and has no counter balance so the motor is braked for parking... > motor runs at 1500rpm, screw is 10mm pitch i am not looking to go any > faster just keep things the same ratings etc > > motor i was looking at replacing with is, as torque match's, > Rated 19.1Nm > Peak 57.3Nm > Rated Speed 1000rpm > max speed 1500rpm > Rotor Moment of Inertia 53.5kg.m2x10-4 > Power 2.0Kw > > or i go the next motor up > Rated 28.7Nm > Peak 86.0Nm > Rated Speed 1000rpm > max speed 1500rpm > Rotor Moment of Inertia 77.8kg.m2x10-4 > Power 3.0Kw > > maybe someone here can add some insight into what to watch out for when > resizing/replacing servos in CNC systems etc > > just when you look up about servo sizing alot talk about the inertia > ratio etc.. > > thanks, Rob > > > ------------------------------------------------------------------------------ > 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 > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ 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 Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
