I personally haven't done it, but I think it should be doable with the servo tool change option. You call a karel program to disconnect the servo before releasing the ATC.
Upon pickup, a similar karel program is called for servo connection.
It is option #J671. Chapter 26 of the spot tool manual goes over it.
The biggest issue I think you'll run into is the encoder positional data for the gun. When robot 1 puts down the gun robot 2 has to trust that it was placed on the perch with the EXACT SAME SETTINGS / POSITION.
This can be overcome with a "autohome" every time the robot picks up the gun, but it will affect cycle time.
The biggest difference here is doing 2 guns on 1 robot, the robot remembers the data from when the gun was unmounted. When 2 robots share a gun, robot 1 can unmount the gun with the servo in a different position that robot 2 will not know about.
The biggest issue I think you'll run into is the encoder positional data for the gun. When robot 1 puts down the gun robot 2 has to trust that it was placed on the perch with the EXACT SAME SETTINGS / POSITION.
This can be overcome with a "autohome" every time the robot picks up the gun, but it will affect cycle time.
The biggest difference here is doing 2 guns on 1 robot, the robot remembers the data from when the gun was unmounted. When 2 robots share a gun, robot 1 can unmount the gun with the servo in a different position that robot 2 will not know about.
Umm, as far as I remember, the encoder battery for the welding gun axis is usually located on the controller cabinet, so a disconnection of the gun would imply it would lose the calibration.
One problem with this is that it will lose his zero, this is usually not a problem as you can recalibrate the tips again knowing the wear but as you are sharing the gun, the robot will not be able to know the current wear of the tip anymore. If compensation is pneumatic it will not be a problem if you track the dressing and wear through one of the robots or even the plc, but if it's compensated by the robot this wear data is important so the robot compensate and actually touch the surface with the fixed cap.
I am a bit rusty right now as I've stopped to work with spot welding a year ago, but one solution may be to handle this data externally and overwrite the wear through a routine that receives the data from the plc or the other robot.
