No. MAMES should never be altered on a robot. And even on home-made external axes, MAMES should only be set up once, before Mastering.
These small differences you are seeing is because the EMT Mastering does not stop exactly at the master reference position of the axis. Instead, the EMT pin is "dragged" across the v-notch of the Master Gauge. The Mastering motion only stops when the pin has registered the very bottom of the v-notch and begins climbing up the other side.
exactly....
mastering position is at the bottom of the V-notch...
and that point is not where EMD mastering starts or ends... it is in-between and closer to where mastering stopped. During mastering with EMD robot moves through V-notch (has to find mastering position) and it stops after it moved past that position...
MAMES tells robot what value to apply during mastering. Those are axis positions when robot axes are at the center of V-notch. And mastering positions can be different for different robots because mastering cartridge location is different:
0,-90,90,0,0,0 is for 2000 series robots
20,-120,110,0,0,0 is for Quantec robots, etc.
Agilus, depending on model, can have different sets of values too
This allows designer to optimize inertia of the robot arm or choose place where mastering cartridge can fit nicely. once the design is done and robot is made, this does not change.
And once the robot is mastered, cannon position is same for all of them so sending robot to position
0,-90,90,0,0,0
Will put robot in the well known cannon position that is also default factory value for home.
So, simply little bit difference in robot position values not means mastering is wrong.
If I do a program to send robot in MAMES -20,-120,110,0,0,0, when reach there, and stop, atual robot position will be those from mastering, or MAMES ones?
If you have done the Mastering correctly, and run an axis to its Mastering position exactly, that's where it should go (ignoring backlash issues). If you were to engage the Mastering pin at that location, it should engage the bottom center of the Gauge notch exactly.
This is how Dial Mastering works. Where the EMT/EMD measures motion, Dial Mastering measures position. When using Dial Mastering, the intent is for the operator to manually measure the engagement of the Mastering Pin vs the Gauge notch, and hit Master when the two are perfectly aligned.
However, since this often involves some "hunting" back-and-forth to find the notch, this adds the backlash of the axis into the Mastering error. Since EMT/EMD Mastering always moves in one direction, it reduces this error.
For most applications that rely on precision/repeatability more than spatial accuracy, Dial Mastering is almost always good enough. In fact, the "field expedient" service-tech method, when neither an EMT/EMD or a dial indicator adapter is available, is to depress the Mastering pin by hand (using a non-metallic probe!) to engage the Gauge v-notch, and use the Dial Mastering menu by literally feeling when the pin hits bottom-dead-center. With care and persistence, results s good as a typical Dial Mastering can be achieved.
