Stringy prints

[lschachtner 0]

Hi everyone,

 

Just wondering if anyone knows what could cause a print have to have strings of PLA extruding from it. Picture attached for reference.

 

Thanks!

[geert_2 558]

This seems to be caused as follows: while the nozzle travels over a gap, it still leaks a little bit. So there is a little droplet hanging on the nozzle. As soon as it meets the next wall, that droplet is deposited against the wall. It is sort of wiped off, and now sitting on the outside of the wall. The next time, the new droplet is deposited onto the previous droplet, since that is the first thing the nozzle encounters in its travel. Next, the new droplet is deposited on that old one. And so on. This causes these strange upwards directed "insect antennas". Printing cooler and slower reduces the effect, since the nozzle does leak less, and pressure in the nozzle is less. But it depends a lot on the material too: in PET I have this a lot more than in PLA, in which it is very rare.