I build an aluminium i3 clone and to get better print results i did some upgrades (like most people do

Many times after i just started a print i'm called away and having a piece of filament messing up the first layers resulting in loss of time and filament..
My solution was to make a little wipebar from a metal paperclip to sheer off the first extruded filament after heating up the nozzle.
Just bend it to size, put a bit of tape on it and drilled 2 tiny holes in the aluminium heated bed.(making sure the nozzle isn't colliding with it when bedleveling or homing)
Then I figured out the x, y and z position to get a nice brushing contact and added this in the start gcode. After G29 i added:
M117 Move naar wipe ;text
G1 F2000 X23 Y0 Z4.5 ;move
G1 F2000 X13 ;move
This way the nozzle is positioned nicly outside my bed so the filament can freely flow..
After extrusion of the filament i retract it 2mm and wait for 5 seconds to stop oozing and then do a wipe:
M117 Extrude 25 mm plastic ;text
G92 E0 ;zero the extruded length
G1 F200 E25 ;extrude 25mm of feed stock
G92 E0 ;zero the extruded length again
G1 E-2 F{travel_speed} ;retract 2mm
M117 Wipe nozzle ;text
G4 S5 ;WAIT 5 SECONDS
G1 F3000 Y5 ;move to wipe nozzle
; M300 S300 P500 ;beep(not in use because it's too loud when printing late

The bar just before wiping: