Controlling a stepper motor with a Kuka system?

[Matthew Neesley]

Hello from Milwaukee:

I'm at the Milwaukee Makerspace; we have a Kuka robot arm, and I'm trying to figure out how to control a stepper motor with the Kuka hardware.  I came across a posting on your group's message board (something about using a "Wago module") and I'd like to know if there was any success with this venture.

I am using SprutCAM to program our robot arm, and it clearly allows for a rotating table to be placed next to the arm, creating, in essence, a giant vertical lathe.  The code also clearly gives axis-specific commands to the rotary axis...so now I just need to figure out how to get a stepper motor to turn the table based on this programming.  Thanks in advance for any replies!

[David McMillan]

Boy, am I behind on clearing my Inbox. Anyway....

It depends. Is SprutCAM treating the external axis as if it were a
built-in KUKA axis? Are you trying to move the axis and the arm
simultaneously.
Without buying a KUKA add-on axis kit and performing a kinematic
integration on it, I don't think there's any straightforward way of
adding an external axis that can move synchronously with the arm.
OTOH, if you simply want to use the external axis as a sort of indexing
table, you have more options. Controlling a Stepper motor isn't too
hard -- you could probably do it with a simple 4-bit or 8-bit digital
output module, as long as it had sufficient current capacity -- I would
go with a dry-contact style output module, myself. The biggest
potential stumbling block would be calibrating the steps/degree to a
sufficient degree of precision.
As for connecting the module to the KUKAbot, well, there are quite a
few options. But, assuming you have a KRC1, that controller already has
a DeviceNet Master port built in. You can easily buy a DeviceNet slave
module, either a simple multi-bit digitial output, or there are also
DeviceNet stepper-motor driver units.