First Layer problem: One of the non-regulated corners is under extruding

[XenonXTX 0]

Hi, guys.

We recently received UM2 for our project and I was excited to have an opportunity to get involved into 3D printing which is awesome indeed!

My project is an enclosure for a tablet.

The print is quite large.

220x165x120mm.

Height is not a problem, nor is the length of the object.

I have a weird problem of under extruding that occurs only in one corner when making first layer, which actually is non-regulated, top-right hand corner.

I need that surface to be smooth as a mirror and just of this behavior, the print is not perfect at all.

I am attaching 2 pictures that are showing the problem.

Another problem is with scratches all over the print, that I have no idea how to fix, although I tried to fine tune Z Hop.

Settings that I use at this moment:

Filament - Atomic bright white 2.85mm

Nozzle - Olsson block mounted - 0.6mm

First and the rest layers - 0.3mm

Speed - 30mm

Bottom layer speed - 25mm

Shell - 1.2mm

Botto/Top thickness - 0.9mm

Nozzle temp 230C

Bed temp 55C

I'd appreciate if you could help me identify the problem.

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Edited January 19, 2016 by Guest

[XenonXTX 0]

And here's another picture showing overall detail of the first layer.

[yellowshark 153]

Ok firstly you are probably printing toooo hot. I am not familiar with your filament but with .300 printing at 25mm/s and 30mm/s I would not go above 210. Indeed for 2nd and subsequent layers I would be trying to see if I could go cooler. Of course filaments affect required extruder temp. but in 2 years of printing normal PLA I have never ever gone beyond 220 and that was for one filament only.

Your bed levelling is probably not level - do it again, take your time and double check it.

I suspect also your nozzle to bed distance is not right. If all of the things I mention do not solve your problem then look at this and adjust your distance.

Raise you bed temp. to 65 ad take your speed from 25mm/s down to 20mm/s. In reality 25 is OK but as you have a problem 20 will be better.

On that geometry I would use a brim to help adhesion - personally I would not even try it without a brim although some people seem to not like brims.

Hell I cannot remember whether the infill speed on layer 1 is adjustable - you want it to run at the same speed on layer 1 - go to the Cura advanced tab and set infill speed to 0 to be sure.

Are you sure your bed (a glass plate?) is absolutely clean? - that hole on the right hand side makes me wonder.

Are you using any type of adhesive? That will help too.

Make sure your fans are not running when you print layer 1

Also if you have another colour then white is not the best for getting a great result; certainly possible but it is probably more inconsistent than most other colours.

Good luck