How can I avoid that a small bit of filament sticks out of the nozzle during heating?


So when my Prusa I3 is heating up, a small bit of filament is coming out of the nozzle, forming a small string at.

When the printing starts, this results in a small plastic ball on the bed, impacting the overall printing process.

How can I avoid this?

Philipp Ludwig

Posted 2017-04-19T15:29:40.200

Reputation: 163

1You might pull back the filament when hot before shutdown, and not feed until hot again? – Ecnerwal – 2017-04-22T03:21:05.387

@Ecnerwal That would be a valid solution, if I weren't just so damn lazy. – Philipp Ludwig – 2017-04-22T16:10:00.470

take it apart with a tweezer. – Fernando Baltazar – 2017-11-26T08:15:16.697



On my Kossel Mini I programmed it to go to the edge of the bed and purge a small amount of filament which creates a dot. I purge enough to get the dot to stick to the bed and then go on with printing, when the head moves the dot stays attached and usually pulls excess material off the nozzle. This can be added to the "Starting G-Code" section of your slicer.


Posted 2017-04-19T15:29:40.200

Reputation: 2 080

This is exactly how Ultimaker primes their filament, I'm also doing exactly the same as this works very well! – 0scar – 2018-07-31T06:27:34.020


I normally print a skirt. This acts as a quality check for: flow rate; bed adhesion; bed level; and proper zero position in the Z.


Posted 2017-04-19T15:29:40.200

Reputation: 2 113

1Very much this! – Carl Witthoft – 2017-04-20T15:44:15.420


I just go and pull it off the print head with pliers when it's about to start and sometimes shortly after it starts printing, but its probably not the safest way to deal with the problem. Printing a skirt, brim, or raft should help to fix the problem.

Brendan Smith

Posted 2017-04-19T15:29:40.200

Reputation: 307