Help with printing

[chenci 3]

Hi, i'm having some issues with a 3d printing. It happens especially in flat surfaces like this box i printed.

You can see there are a lot of uneven surfaces and gaps between the lines. I'm not sure if it is underextruding. The first two layers are perfect. The problem happens in the last layers.

Also i have calibrated the steps/mm and i use PLA at 205° - 0.4 Nozzle

This are my settings:

I use 60mm/s print speed but strangely, it prints at 30mm/s average.

Thanks for any help.

[zoev89 73]

Did you measure your filament diameter? Could there be a significant difference.

It is difficult to judge from the photo what the effect is. For under extrusion usually you see small gaps between the lines but to me it more looks like over extrusion because I can't see the small gaps but I think I see blobs of excess material.

[chenci 3]

Yes i measured the filament diameter, it's 2.85 to 2.9. I've uploaded new photos. There are blobs but very small. Mainly i get an rough surface that feels like touching a fine sand paper.

I still have my doubts, is it under-extrusion? or over-extrusion?

I use Flow100% Retraction 6.5mm at default speed. Firmware Tinkergnome 17.02.1

Edited May 10, 2017 by Guest

[neotko 1,417]

My 2cents. Your first layer is too close to the bed and the layer on top keep doing full layers, making the tidalwave pattern raise to the top. Does your first layer look perfect or with small 'waves'?

[chenci 3]

My 2cents. Your first layer is too close to the bed and the layer on top keep doing full layers, making the tidalwave pattern raise to the top. Does your first layer look perfect or with small 'waves'?

 

Hi, thanks for the reply. As i said in the first post, the first two - three layers are perfect, doesn't have any artifact or small waves. The problem happens in the last layers. I will level the bed and try again.

[neotko 1,417]

Just post a photo of the bottom, if shows a weird pattern it might be that.

[yellowshark 153]

Hmn, I must say I was thinking the same as @neotko, although your first layer is perfect.... Out if interest, how many layers does the flat surface have and what layer heights are you using for first and subsequent layers?

[geert_2 557]

At first I was also confused, since some parts in the original photo seemed okay, some seemed gaps and underextrusion, and some seemed blobs and overextrusion. But when seeing the new photos, and when seeing the original in Photoshop with only the blue color channel (blue is opposite of orange, and shows more contrast), then it is clear that there are lots of gaps. So I guess it is underextrusion. If one layer is underextruded, then of course the next layer will sink into the gaps left by the previous layer, causing an irregular surface.

Could it be that printing PLA at 0.2mm layer height and 60mm/s is a bit too fast or too cold for this combination, so the filament has not enough time to melt? This maybe in combination with tightly wound filament near the end of the spool, or with a worn-out teflon coupler?

What happens if you print it at 215°C or 220°C?