How do you prevent drooling of the extruder nozzle?

After each print I have some drooling out of the extruder nozzle, when the extruder is in park position and cooling down. It is just annoying to heat up the nozzle before you can start the next print and do an Z axes zero... But even when I clean the nozzle I have the issue on the next heat up, filament coming out and sometimes even ruining my print as it get's somewhere in between.... I was hoping that M227 (Enable Automatic Reverse and Prime) is supported, but at least not in DC42 firmware. So I couldn't try, not sure if it would help.
What are you doing to solve this issue? Retraction in stop g-code? If so what amount?

Thanks

Peter

In your end gcode in slic3r or whatever other slicing program you use, before the M0 or M1 command at the end, insert G1 E-5 F4000 to retract 5mm of filament. Then, in your start gcode, add G1 E5 F200 to undo the retraction, or just make sure that the minimum skirt extrusion length you have configured uses up more than 5mm of filament.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

No need to heat up the nozzle before homing. Just pull the X carriage to the end of the arm and scratch off the plastic that has oozed with a fingernail after it is cool, then home with a cold hotend. Do not use any abrasive or hard tool to break it off - it you scratch the bottom of the nozzle it will not ride smoothly over the molten plastic it is laying down and you'll get lots of breaks in the extruded lines (BTDTGTTS). The same is true if there is any burnt-on foreign material on the bottom of the nozzle.

Forgot to mention - another way to prevent the ooze is to park the nozzle over a corner of the bed in the end code and lower to zero. The bed will then block the nozzle and prevent oozing. It has to be in a position over the bed where the hotend will not hit the print of course.

Dave

Edited 1 time(s). Last edit at 02/13/2015 11:02AM by dmould.

A tip regarding wiping the tip of the hot end. If some oozing has occurred when the hot end heated up anf you want to wipe it off. A piece from a failed print works very well. Hot PLA sticks very well to cold PLA, compared to using a screwdriver, paper or something else. Leaving a clean tip with all hot plastic removed. Do not touch the actual tip just the hot plastic.

Speaking for my self; I have no shortage of failed prints