This is how I solved a problem of having to wait and manually remove the oozing filament from the nozzle every time the printing starts.
The servo holder is positioned such (picture 2) that the wiper can hit the center of the conical part of a nozzle (picture 3) and then slide over the tip of the nozzle as it moves further.
The servo used in this design is a 9g TowerPro SG90.
The design also requires some 2mm screws for plastic: 2 countersunk to attach the servo holder, 2 round headed to attach a servo to the holder, 1 that comes with a servo arm, 1 to attach the wiper to the servo arm.
You will need to modify the Marlin firmware of your printer to enable one or more servos.
In Configuration.h defines: NUM\_SERVOS and SERVO\_DELAY.
And in your slicer software you will need to add some code to do the wiping action at the beginning of each print. For example:
; ...
; After the bed has heated up.
;
;--- Servo nozzle wiping ---
G91 ;relative positioning
G1 Z10 X30 F900 ; lift Z axis, move head away
M400 ;wait to finish moves
G90 ;absolute positioning
M280 P0 S870 ;move servo back
G28 X ;home x axis
M280 P0 S2000 ;move servo forwards
M280 P0 S870 ;move servo back
G28 ; home all axes
;---
An updated design ServoOozeWiper5-wiper has two prongs and needs a shorter g-code script:
;--- OOZEMeNaught wiper ---
G91 ;realtive pos.
G1 Z10 X30 F900 ; lift Z axis, move head away
M400 ;wait to finish moves
G90 ;abs. pos.
M280 P0 S2000 ;move servo forwards
G28 X ;home x axis
M280 P0 S870 ;move servo back
;---