Lift Switch problem

[c5m7b4 1]

Hello all,

recently I have been having a problem at the begining of a dual extrusion print on the Ultimaker 3. I have had the printer for a while now, and its a printing beast for the most part. Recently though, when getting ready to use the Lift switch for the first time in a print, the head will bang against the side of the printer making a really loud noise and then fail to connect with the lift switch. This results in printcore 2 being higher than printcore 1, so placing filament is a no go since its too high above the build plate. Also when this happens, its like the XY is all messed up and it tries to print the PVA about an inch away from where it is supposed to print. I have done an XY calibration and a lift Calibration to no avail. Does anyone have any ideas. It doesnt happen every time. I have used two different laptops and tried multiple different files. 

[gr5 1,931]

There is a lift switch calibration procedure you can run on the UM3.  It's in the menu system somewhere.  It sounds like you need to do this.

[c5m7b4 1]

I have done the Lift switch calibration and it seems to go smoothly. Is is possible that there is something going on with the GCode. Does anyone know what the gcode commands are for the lift switch. Maybe I can dump the logs and check there to see if there is a problem.

[gr5 1,931]

It's just a "T0" to go to the left core and a "T1" to go to the right core.  That's it.

[gr5 1,931]

What state/country are you in?

[c5m7b4 1]

Nashville, TN USA baby! I'll see if it happens tonight when I setup to print and if so, I'll check the gcode and see if there is something fishy going on.

[somethingcreative 0]

I'm having the same problem. Ultimaker S5 (Pro Bundle). Have since: calibrated the lift switch, aligned the axles and recalibrated the x and y offsets, rebooted the system, adjusted the y-axis limit switch as far forward as possible, tested the limit switch by auto homing and manually engaging the y-axis limit switch before the print head reaches the switch and resized the print bed to a smaller size in the printer settings. Everything is operating within normal parameters and yet still running into misalignment of the lift switch during the print process. During initialization process, the lift switch engages and disengages fine. Once the print sequence begins, extruder one prints well, but then travels past the lift sensor and crashes into the frame.