goofy first layers

General LulzBot TAZ
1

hey all,

I’m trying to trouble shoot this problem which is occurring on some of my larger (~ 160mm) prints.

I am thinking it has to do with the default extrusion width in slic3r. I was using some of lulzbot’s profiles but making some changes to the speed, layer heights, and various other settings and didn’t realize that the extrusion width was set to something besides 0. So this print might not have had an optimal extrusion width.

However it could be something totally unrelated. I’m thinking it might be related to printing with a brim?

Also you may notice on the long, flat side of the object the layers are warping a bit as we travel up the z. The lower layers seem to be cooling at a different rate. This effect was much mroe pronounced when I was running the heated bed at 110C instead of 85C now.


http://imgur.com/a/p4sFZ

; layer_height = .25
; perimeters = 4
; top_solid_layers = 5
; bottom_solid_layers = 5
; fill_density = 0.2
; perimeter_speed = 80
; infill_speed = 120
; travel_speed = 200
; nozzle_diameter = 0.35
; filament_diameter = 2.89
; extrusion_multiplier = 1
; perimeters extrusion width = 0.36mm
; infill extrusion width = 0.36mm
; solid infill extrusion width = 0.36mm
; top infill extrusion width = 0.34mm
; first layer extrusion width = 0.30mm

Any thoughts on why the first 8 layers or so look so much rougher than the rest of the print?

2

I’ve been running into similar issues. It seems to be if the bottom of the print is solid and then has ‘walls’ (think like a vase), the layers for the solid bottom will be all screwy, but then the walls will print nice and smooth.

3

infill speed may be too high

4

What would cause this to affect only the first layers?

5

Maybe a level issue? I’ve found that you have to level when hot, not cold… heat expansion and the way the mat is working cause the glass to distort slightly from cold to hot…

At least in my experience…

Alan

6

Could be. I’ve been finding that I need to do the bed-leveling print before pretty much any print.

7

true.

What material are you using?
using any ABS juice? or hairspray? (hairspray has been suggested to affect shrinking of the first few layers).

what is the % speed difference for the first layer? that would be my first look.

try printing with raft. It’s more material to remove, but may give you the look you are going for. It will certainly remove any issues with a non-level bed.

8

I am thinking my z might be too low.