unclean first layer

[facebraker]

Hi,

I was skeptical at first about Simplify3D , but i had big problems with my printer and Slic3r.
So I tested, I had nothing to lose, only to win

And i have to say, is great, perfect printouts, very very good supports - easy to remove ---> great.
Very good rafts and easy to remove.

But i had one problem, the first layer ist ugly, the top layer is pretty but the first layer seems to much space.

Have a look:



I use a raft, easy to remove but the first layer is not good.

In different the top layer:



is perfekt.

Can you help me to optimize the first layer?

Thank you!

Greets Alex

[dorsai3d]

Yep! One step makes this all better!

1. Dont use a raft.

Problem solved!

Seriously, I don't get why everyone loves rafts, they're a waste of time and material. If you can get a raft to print, but can't get your first layer to print, you should adjust your first layer settings or bed, rather than use a raft. Not once have I ever had a part that needed a raft to print, and I've been printing since 2012.

[facebraker]

Hi dorsai3d,

maybe you're right. i had some problems with nonstick object, but i suspect the real problem was the missing nozzle fan.
in the ground it was a thermal problem, the objects deform a loose from the bed.
After i attach a nozzle fan, from this point i had no problems with deform objects an nonstick object.
But i still used the raft ... maybe a fault ...
i will try to print without raft, until 12pm a have a running print

thanks, I'll report here

Alex

[Rebekah_harper]

The first layer of the part when using a raft is at default speed.

I have raised this with the team and am waiting for a reply.

if you want to still print with raft then edit the GCode file in notepad.

with a single layer raft press ctrl+F and type "layer 5" this is the first layer of the part.

I use the speed of 1000mm/min

hope this helps

Becky

[facebraker]

Hi Becky,

thank you for your reply.

I have checked the gcode file, but i didn't find a speed, do you mean the feedrate-speed?

Here is my sample:

Code: Select all

; layer 5, Z = 1.68714
; tool H0.236 W0.300
; inner perimeter
G1 X90.982 Y74.934 F4800
G1 Z1.687 F1000
G1 E0.0000 F1800
G92 E0
G1 X92.108 Y74.557 E0.0349 F2000
G1 X93.249 Y74.231 E0.0698
G1 X94.403 Y73.956 E0.1046
G1 X95.569 Y73.732 E0.1395
G1 X96.744 Y73.561 E0.1744
G1 X97.925 Y73.442 E0.2093
G1 X99.110 Y73.376 E0.2442
G1 X100.297 Y73.363 E0.2791
G1 X101.483 Y73.403 E0.3139
G1 X102.667 Y73.495 E0.3488
G1 X103.844 Y73.640 E0.3837
G1 X105.015 Y73.838 E0.4186

Can you please explain the the think behind the speed -change?
We change the speed cause : ... the result is ...

Sorry i'm new in the 3D Printer Business

Thank you

greets Alex

[facebraker]

Good Morning,

hey dorsai3d, can you help me or someone else ...
In my weekend i checked the print directly without raft.

Short explain: fiasco!!

when i print with raft, the first layer (the extrusion) on the bed is thick with perfect adhesion the bed.
Maybe is it the config of the raft , its work fine.

curtain on - my trial without raft:

the extrusion is very thin, like a normal layer 0.1mm ... but it don't stick on the bed, especially in curves , sometime it stick and then non stick and it create hexagon or pentagon.
ugly ...

can you explain me how i config the first layer get , thicker extrusion , better stick extrusion, better print result.
IMHO i think the extrusion is to thin ...

Here is my config for the extruder:



I level the bed with a distance between extruder an bed with 0.1mm

Extruder temperature : 190°C
Bed temperature: always 60°C

If you need a short result video , no problem.

Thank you!

Greets Alex

[dkightley]

Your settings show a first layer height of 90%......which is exactly what you're saying is happening.

Change it to say 150%....or even higher, 200%....and try printing again.

If the results are a non-smooth surface on the bottom, you could amend the Global offset for the Z axis to say -0.1. This lowers the print down by that distance.

[facebraker]

Hi dkightley ,

thank you for the tipp, i will test it.

for my understanding, the first layer is set to 90% to get a smooth bottom surface?
that mean, the printer print always 10% to low in the Z axis?

Can it also help to increase the thickness of the first layer to >100% to prevent gaps in the first layer?

For the global Z offset , 0.1mm for 200% and 0.05mm for 150%?

Thank you!

Greets Alex

[dkightley]

for my understanding, the first layer is set to 90% to get a smooth bottom surface?
that mean, the printer print always 10% to low in the Z axis?

The first line thickness purely adjusts the thickness of the first layer. The only change in the z axis is to adjust for the thickness of the layer.....not the relative height of the "bottom" of the model.....so your understanding is not correct.

Can it also help to increase the thickness of the first layer to >100% to prevent gaps in the first layer?

As above, the thickness of the first layer has none or little effect on the quality of the bottom surface. Vertical positioning of the model in relation to the bed does....and this can be easily adjusted using the global z offset as I suggested.

For the global Z offset , 0.1mm for 200% and 0.05mm for 150%?

Again, the layer thickness has little effect on the quality of the bottom surface. The negative z axis offset I suggested is a figure to try for a start....you'll need to test and adjust accordingly to achieve the results you want.

[facebraker]

Sorry Doug,

I have confused the top and bottom, that explains my questions.

Sorry, monday morning and not native tongue, my fault.

Ok, the bottom offset fit 0.1mm in the Z axis , result a smooth buttom surface and the rest object is relative correct.

i will test and report.

BIG thank you!