Problems with first (and final) layer

[dansch]

Im trying to get my first good print now for several weeks - but i'm still stuck with two major problems:
(PLA, Hot-End 190°, Head-Bed 60°, EZStruder, Firmware 0.91, RepetierHost and Slic3r, 0.5 Nozzle)

Although i did the printer calibration and the paper test for the 4 reference points, my first layers don't really look flat.
It seems as the printed lines are "pushed away" by the following ones, forcing them to make "waves" - which causes the next layers to get errors to.
Also the PLA doesn't really stick to the heated bed, so the first rounds of filament get stuck to the hotend and carried with it.
I thought mayby it's just too much material extruded, but on the final layer it seems like the lines make gaps between them which leads to a not solid surface...

Sometimes the printer manages to overcome the first layer but then i get prints with hairlines (right word?) on the sides of them.
Or the printed lines fall apart completele...

I'm really running out of ideas as i can't even manage one usable print at this time...

Daniel

[Eaglezsoar]

Are you running a layer fan?

[geneb]

Were you able to print the calibration cube without errors?

Just FYI, the fan shrouds should be printed in ABS. You'll have a mess on your hands if you use a PLA fan shroud with a hot, hot end.

g.

[dansch]

i'm not yet using a fan because i don't get the mounts printed corretly. i know they shouldn't be PLA, i tried in nylon but that worked out even worse...
may my problems depent (only) on cooling?

[Eaglezsoar]

i'm not yet using a fan because i don't get the mounts printed corretly. i know they shouldn't be PLA, i tried in nylon but that worked out even worse...
may my problems depent (only) on cooling?

ABS does not require a layer fan and that is what I would use to create the mounts for the layer fans.

[MSURunner]

When in PLA, I usually either add a brim to the part or lay down some tape if I'm having trouble getting the PLA to stick. If that doesn't work, you can try a brim on tape. If THAT doesn't work, the glue stick/hairspray seems to get just about anything but nylon to stick. For nylon, you will want to use some sort of fibrous material such as wood to print onto. But before you get too involved, you are going to want to get your extruder calibrated. You look to be over-extruding/running too hot. Both need to be sorted out as well. So, start out with some calibration cubes/parts. If all you have is PLA and nylon to print with, I would get a desktop fan pointed at the build surface while you are printing. That is a temporary solution, but should get you to produce a decent part to get you closer.

[Toyguy]

It's dependent to varying degrees on the filament, but I found 60/190 for PLA to be too cold. I'm now printing my PLA at 65C on the bed, and 195-200C (varies by color a little) for the head. Of course, I'm in Vermont where it's cold this time of year so that may also be a factor.

I also always use blue tape or, more recently, glue stick, to adhere the parts. I've had no issues with part lifting at all.

[Tinyhead]

I couldn't get my PLA to stick initially either. I ended up using blue painter's tape and rubbing a bit of isopropyl alcohol on it (you can get it at a pharmacy). Don't heat the bed. Just cold with tape cleaned with alcohol. You definitely need a fan blowing on the parts while printing though. Even if it's not the SeeMeCNC fan... just a regular house fan. My first object was the calibration cube which I started without the fan and I can physically see when I put the fan on it. It made a HUGE difference. I would just try to get your first layer to stick to the bed properly, then post some more pictures to see what else might need fixing.

Could you post a side view of one of the objects you printed? Just curious about your layer heights.

[Nylocke]

Is that SeeMe green PLA?

[dansch]

I now tried higher temps (65/195) and a brim. I tried to use a desk fan too.
That works pretty well for the first layer. There are still little waves sometimes, but these are really minimal problems (just approx. 0.2mm high).

I also increased the retraction from 2mm to 5mm, the number of hairlines decreased but they are still there.

Also the final/top layer looks better. The surface still looks not quite closed, but the gaps are much smaller than before.

I'll try several other prints (now i just did the calibration cube) and will post photos of them.

Thanks for the great tipps!

[mhackney]

Can you post the header section of the gcode file or the entire file? I'd like to see what speeds you are printing at too.

Also, you never want to use a fan on the first several layers on PLA. You want these to stick to the bed and cooling at this critical time can cause them not to stick.

Blue tape cleaned with isopropyl alcohol on a room temperature bed is guaranteed to work. If you can't get it to stick to that then you need to check your Z=0 setting, print speeds, PLA diameter (and set that in the slicer) and contamination (especially silicone). If you print on blue tape at 60° you will NOT be able to remove the tape from the part.

What are you printing on? It looks like bare glass. PLA is not going to stick to that very well.

[dansch]

Actually i print on bare glass (60°) at the moment (cleaned with acetone), as i don't have blue tape.
I activated the desk fan after the first layer, wich worked good for the moment, in the slicer i deactivated the fan for the first layers anyway (as soon as i have my fan mount printed )

here the gcode head:

Code: Select all

; generated by Slic3r 1.0.0RC2 on 2014-03-03 at 17:14:32

; layer_height = 0.4
; perimeters = 3
; top_solid_layers = 3
; bottom_solid_layers = 3
; fill_density = 0.2
; perimeter_speed = 30
; infill_speed = 30
; travel_speed = 200
; nozzle_diameter = 0.5
; filament_diameter = 1.75
; extrusion_multiplier = 0.95
; perimeters extrusion width = 0.50mm
; infill extrusion width = 0.53mm
; solid infill extrusion width = 0.53mm
; top infill extrusion width = 0.53mm

[MSURunner]

Also the final/top layer looks better. The surface still looks not quite closed, but the gaps are much smaller than before.

^Tells me you do not have your extruder properly calibrated and are likely making up for it by having your z-height too low to start. This is causing your nozzle to drag across the material and is ripping it off the bed...

[Tinyhead]

One thing you could try too is to change your extrusion width settings. Even just as a test. Another good thing to do is take measurements with a set of verniers over various points on a few meters of filament then take the average of the readings. It'll help dial in the extruder so it's not pushing out too much or too little.

; layer_height = 0.2
; perimeters = 3
; top_solid_layers = 3
; bottom_solid_layers = 3
; fill_density = 0.2
; perimeter_speed = 30
; infill_speed = 30
; travel_speed = 200
; nozzle_diameter = 0.5
; filament_diameter = 1.78
; extrusion_multiplier = 1
; perimeters extrusion width = 0.60mm
; infill extrusion width = 0.60mm
; solid infill extrusion width = 0.60mm
; top infill extrusion width = 0.40mm
; first layer extrusion width = 1.05mm

That's what my settings are for some of my prints. You could changing the widths to 0.6mm; I've read a few guys on here use that number as a safe medium.

Looking back at your original pictures, I'd wonder about the Z-height. That first layer looks really squished flat and if you're getting any ridges from it pushing the material around, the next pass is going to hit knock it loose on the bed. But it is a bit hard to tell, so I may be wrong.

Last thing. You can try pulling up a file in repetier, then use Slic3r (kind of built in) and make some changes to that top layer width. Then go to the 'G-Code Editor' tab and take a look at how the top seems to be filling in. Try a different setting, save and go back. You might find a width or a fill percentage that works better for you.

Testing with top fill to make the prints nicer and more whole.

As you can see in the picture, the one on the left had a much nicer finish to the top layer and didn't leave much room for gaps.