3DBenchy smokestack issues

[Lemma 0]

Hello UM2 community,

I'm trying to calibrate my UM2 with the 3DBenchy print. I'm having two issues, lots of stringers and some deformities in the smokestack. The odd thing is that the print overall has come out quite nicely. I'm using Simplify3D as the slicer and silver Ultimaker branded PLA 3mm.

Any help would be appreciated.

First layer temp 210 C, then all others 205 C

Bed temp first layer 65 C then 60 C.

Edited July 1, 2016 by Guest

[chrisw 70]

For most of that Benchy project your print head goes over an area laying down hot plastic. The nozzle moves along to other areas and the hot plastic cools while the nozzle is busy elsewhere. Then the head comes back and lays more hot plastic on top of the cooled areas.

That changes when the printer gets to the smoke stack. Now the nozzle lays down hot plastic, circles around a few times really fast, then lays more molten PLA on top of the still-warm plastic. That happens again and again, so the heat builds in that smokestack. The whole thing is hot, and more layers added on top add more weight, making it sag.

A few ways to deal with it:

- make sure the fans are at 100%

- decrease the nozzle temp when it gets to the smoke stack base layers.

- decrease the print speed when it gets to the smoke stack base layers.

[Lemma 0]

That makes perfect sense, thanks!

[StephanK 30]

Since you're using Simplify3D, maybe give this a try: Go to the Cooling tab and experiment with the Speed reduction Settings in the upper right: "Adjust printing speed for layers below xx sec" and "Allow speed reductions down to xx %". I currently got mine at 10%  (of default printing speed of 2700mm/min and the smoke stack prints fine with most PLA printed at 210°C.

Edited July 2, 2016 by Guest

[Lemma 0]

I'll try that, thanks!