Hello,
I would like to install an external seventh axis on my Kuka robot KR C2 from 2010, which would perform rotation along the Y axis. I have found all the necessary components for this modification, but I would appreciate it if someone could clarify if there is anything else I might need. Also, does the Kuka robot automatically recognize the new axis, or is additional configuration and networking required in the software?
Thank you in advance for your help!
7TH AXLE ELECTRICAL CONNECTION FOR KRC2
OUTER SHAFT CONFIGURATION
Do you think I can do this connection by myself AND software. I have knowledge in reading and I understand them. Do I need any device for this apart from the necessary components
How many axes does your KRC2 currently have? Does that 7th axis unit have a KUKA servo motor on it?
Adding a 7th axis to a KRC2 is usually quite simple, if you have the correct components. Hardware detection is automatic to a limited degree, but configuration and tuning must be done manually.
Typical KRC2 can support up to 8 axes. If you look inside the KRC, the white modules are the power module (first module) and the individual servo modules (N1-N6). The empty space in the top left corner is for adding 1 or 2 new servo modules.
The internal cables for connecting the new servo module (N7) to the power supply are already in place -- they should be hanging, unconnected, in the upper left corner. The cables to run from the N7 module to the motor, however, you will have to obtain.
The white cables daisy-chaining from module to module are the Interbus communications. You will need to add a cable from the open port on N6 to the first port on your new N7.
The resolver cable from the 7th axis motor needs to run to the RDC card in the base of the robot arm. This card can support up to 8 servos, you will need the correct cable and connect to location 7 on the RDC. There is an opening in the RDC box to permit this, closed with a screw-in plug. You will want to use a cable gland to seal the new opening.
KSS 5.x includes an axis configuration tool for setting up External axes. You will need to set the correct KUKA Servo motor, then tune the N/D values for $RAT_MOT_AX until the rotation of the axis in physical reality matches that on the teach pendant (that is, 90deg on the pendant achieves 90deg in reality).
You will need some sort of reference to Master the 7th axis. How you do this is up to you, but it needs to be precise enough that, if/when Mastering of the axis is lost, you can recover with sufficient precision.
I am sending you pictures of the driver in the attachment. Do you feel that the schema above that the user sent me is quite sufficient for networking everything?
The green rectangle marks a blank cover plate that needs to be removed for the heat sink of the new servo module to pass through. If you unbolt N6 and pull it out (it's simple, just a bolt at the top, french cleat at the bottom), you'll see how it's supposed to work.
The red arrows mark the Interbus cables. On every module, the connection from upstream goes into the red-marked RJ45 socket, then the other socket is the "out" connection to the next downstream module. So if you add N7, you'll need to add a short cable from N6 to N7, just like the cable linking N5 and N6 in the image. You'll need to source that cable.
The yellow arrows mark the high-voltage connections of the module. IIRC, the cables for the top connection should already be in the KRC, just dangling. Rather like the one the white arrow is pointing to.
The bottom connector, though, is (again, IIRC) part of the external axis upgrade kit from KUKA. That's the connection from the servo module to the motor. Typically, KUKA sells (well, sold) a cable that plugged into that lower connector on the module at one end, and the other end ended in a socket that mounted to one of the blank holes in the lower bulkhead of the KRC (alongside X11 and the others). This socket came in different sizes, depending on the current rating of the servo -- the big KUKA servos requires a larger socket (and thicker cable). Then there was a standard servo cable (not KUKA-specific, it's a generic cable but I don't recall the name of the plug standard) that would run from the new socket on the KRC out to the motor. This needed to be ordered to length. You will need to source these cables yourself.
That should be the end of the hardware changes in the KRC. You will still have to handle running the resolver cable from the servo to the RDC.
KRC side wiring
1. install correct frame for drive (remove blank)
2. install drive
3. connect drive power 600VD (black wires)
4. connect drive control power 24VDC (blue wires)
5. connect drive comms (Interbus)
6. connect drive to motor
7. connect motor brake.... this can be done with or without SMB so there are two wiring possibilities here. SMB is needed if external axis must be stopped by some safety circuit (other than robot safety). this is needed when operator needs to approach external axis (such as turntable) while robot is enabled. or if there is another external axis with SMB that it is powered from same KPS600.
RDC/RDW side wiring
1. connect motor feedback cable to RDC and make sure shield is connected to RDC box
Software setup
Adapt parameters for your axis. list of parameters that need to change can be seen here:
