UM PLA misprint: how to correct

[3dprint2go 0]

Hi,

I have printed a whistle I got from Thingiverse (1179160). I used PLA filament from Ultimaker with the following print settings:

 

Quality (layer height)	Fast & low 0.2 mm
Shell thickness	0.8 mm
Bottom/Top thickness	0.8 mm
Fill density	100%
Speed (mm/s)	40
Combing Mode (Retract)	No Skin
Ironing (pattern)	Zig Zag
Iron only highest layer	No
Initial Layer Thickness	0.3 mm
Material	PLA Yellow | UM
Scale	100%
Nozzle temperature	220
Buildplate temperature	70
Glue	None
Support type	None
Platform adhesion type	None
Travel speed nozzle	120 mm/s

 

 

Unfortunately, the all surfaces (top and all sides) are not smooth and have material as small points sticking out. (See attached picture)

Can anyone recommend what to do to prevent this effect?

[gr5 2,172]

What kind of printer?  Oh - I can see "ultimaker" in the background.  Um3 or Um2?

 

I'd raise the speeds from "40" to 30 (yes raise).  Make sure all the printing speeds are at 30.  This might not be the issue so report back.  Also lower the temp (this is probably the more serious issue) to 200C.  Check all the nozzle temperatures.  Some filaments make these bumps more than others and they usually go away if you print cooler.

 

HOWEVER I see you have ironing on.  The only part of this print that ironing helps is the bottom of that doorway where the floor is flat.  I recommend you turn ironing off because it might be causing these bumps.

 

Ironing is great for very flat things.  Like a large coin.  I've never tried ironing so I don't know but it seems like exactly the thing that might cause these bumps.

 

Oh - and 70C is too hot for the bed - it won't cause what we see here but it can cause "wall cave in" as shown here:

http://support.3dverkstan.se/article/23-a-visual-ultimaker-troubleshooting-guide#wallcavein

 

[yellowshark 153]

Hi, yup agree with 100% with @gr5 comments. You do not mention it but set max. fan at 100%. Also walls, I suggest you go for at least 2 walls assuming a 0.4 nozzle. I normally use 15% overlap between infill and walls. Using a skirt to get the filament flowing consistently before starting the model can only help if you are not using a brim.