Extruder hitting top of print at the end

[azjulian 0]

I have been printing some tall prints recently and noticed that at the end of the print the cycle the print goes through (I have an ultimaker 3) its hitting the extruder on the top of the print.

 

I'm using Cura 4.5.0

Printer Firmware is 5.2.11.20190503

I'm printing over the network but did save a recent file;and a short video of the end of that file

UM3_VL fuselage 2.gcode DSC_3342.zip

[Guest maht]

Nice wing.

 

Judging by your video, I have a hunch that something is obstructing your Z axis, because there is a weird crunch about 6 seconds in as the bed lowers before the head makes contact with your print. If the z axis is missing steps, then there's a chance the head could make contact with the print even though the bed is lowered to a 'safe' position.

 

Remove anything inside the machine (tools etc) that may be obstructing the bed when it lowers. Raise the bed and inspect for any debris near the z limit switch. Sometimes the nozzle prime poop can find its way in there. Also consider lubing your lead screw/smooth rods while you're at it.

 

Hard to diagnose these things from afar but that crunch doesn't seem right at all.