Help with bottom layers.

[Kruino 0]

I'm getting some weird bottom layers from my ultimaker 2 extended. Is it possibly a calibration thing, is the printer just not aligned probably or is it some print settings?

I would like some help if anyone know of the problem. Since I am quite new to 3d printing. Thank you in advance :P

Printer:
ultimaker 2 extended
standard hot end
0.4mm nozzle

[gr5 2,265]

This is called underextrusion and has many many causes but for the bottom layer only, the most common cause by far (95% of the time) is that you have bad leveling.  In otherwords you want the nozzle and bed closer together.  You can prove this by pushing up on the bed while it prints this layer.

 

You can do the calibration again but I recommend you practice a new trick.  When it's printing the brim, and it's underextruding you want the bed to go up closer to the nozzle so you think about this (don't panic - it's confusing at first) and rotate the 3 screws counter clockwise (as seen from below) equal amounts. It's important to do equal amounts as the bed is hopefully already level.  If one side has more underextrusion than another then you can just raise that screw but that's even more confusing as the 2 corner screws move that corner one way and the opposite corner the other way.

 

The first 10 times you do this it will be hard and you might not finish before it gets to the print and you'll have to restart.  After doing this for every print (even if it doesn't need it - just for practice) for a while it will come naturally and you'll always automatically turn the screws the right way.

 

But in order for it to become automatic you can't just turn a random way and see what happens.  You need to always turn it the correct way to get that into muscle memory.  Which means you have to slow down and think... which way do I want to move the bed... okay which way does that mean I turn the screws.  If you calculate that part wrong you will learn the wrong muscle memory.

 

If I'm wrong and it's not your leveling, then it will underextrude on every layer, not just the first.

[Kruino 0]

28 minutes ago, gr5 said:

This is called underextrusion and has many many causes but for the bottom layer only, the most common cause by far (95% of the time) is that you have bad leveling.  In otherwords you want the nozzle and bed closer together.  You can prove this by pushing up on the bed while it prints this layer.

 

You can do the calibration again but I recommend you practice a new trick.  When it's printing the brim, and it's underextruding you want the bed to go up closer to the nozzle so you think about this (don't panic - it's confusing at first) and rotate the 3 screws counter clockwise (as seen from below) equal amounts. It's important to do equal amounts as the bed is hopefully already level.  If one side has more underextrusion than another then you can just raise that screw but that's even more confusing as the 2 corner screws move that corner one way and the opposite corner the other way.

 

The first 10 times you do this it will be hard and you might not finish before it gets to the print and you'll have to restart.  After doing this for every print (even if it doesn't need it - just for practice) for a while it will come naturally and you'll always automatically turn the screws the right way.

 

But in order for it to become automatic you can't just turn a random way and see what happens.  You need to always turn it the correct way to get that into muscle memory.  Which means you have to slow down and think... which way do I want to move the bed... okay which way does that mean I turn the screws.  If you calculate that part wrong you will learn the wrong muscle memory.

 

If I'm wrong and it's not your leveling, then it will underextrude on every layer, not just the first.

This does indeed seem like it has fixed the issue with the gaps in the skirt. There is a bit in the print itself though. So I was also wondering if this was if setting. or if it is meant to look like that on the first layer.

and thanks for the tip about levelling the build plate doing the skirt print. It helped a lot :D

Edited July 1, 2023 by Kruino

[gr5 2,265]

This is just strange.  The skirt doesn't have much underextrusion but then the infill has quite a bit.  Also the filament changed from white to a more yellow color????

 

I'd like to see a few layers higher up to be sure you have underextrusion higher up but what it looks like to me on the bottom layer is that:

1) no underextrusion for the skirt and then

2) you get underextrusion for the diagonal lines (the skin - top/bottom layers are called "skin")

 

Did you change the screws in between?  I assume not.  So this implies underextrusion starts maybe 4 minutes into the print.

 

I'm thinking you have issues with your telfon part.  Those tend to start after you start retracting and moving heat up into the teflon area on a UM2/um2+ and you had retraction to make those 3 ellipses.  So:

 

How old is your telfon part on your UM2?  How many hours do you have on the UM2 (you can check in the advanced settings somewhere).  

 

Also is the rear center fan working?  It should start spinning anytime the nozzle is above 60C.  The symptom for a bad fan is that you start getting underextrusion several minutes (5 to 20 minutes typically) after starting the print.