Hot end scrubber made from a dremel wire cup brush I had laying around.I have a problem with goop being melted onto the outside cone of the hot end, and with my new fan mount it is a pain to get at it manually to clean. So I designed this little guy to automate the process.For this to work you need to have at least a 30mm gap between the edge of your heated bed and the side extrusion. I am using a 1in diameter dremel wire cup bit but something slightly smaller or larger could work as well, depending on how big of a gap you have to work with.The mounting hole is sized for a M4 drop in t-nut, and there is a M3 set screw with nut trap. The shank of the dremel bit is 1/8 in diameter.Print and install. You will have to move your X end-stop far enough so that the hot end can reach the wire brush, adjust height of the bit as desired and secure using set screw. I cut away half of the wires not facing the printer to make it easier to remove the purged plastic.Here is my start-up gcode:G90 ; Set to absolute positioning G28 X0 ; Home X, X home is middle of cup G28 Z0 ; Home Z G92 E0 ; reset extruder G1 E5 F100 ; Purge 5 mm G92 E2 ; Reset extruder for retraction 2mm G1 E0 F1000 ; Retract G1 X20 F4000 ; Move to bed X0, 20 mm from X home G92 X0 ; Set current X at Zero G28 Y0 ; Move to Y0 G1 E2 F1000 ; Prime extruder 2mm G92 E0 ; reset extruderVideo of a print start: http://www.youtube.com/watch?v=MKWgGMjsx8U