I switched printing filaments from white to green, both same type of PLA from the same manufacturer and ordered at the same time.
The prints were coming out fine in the white PLA, but I just ran a first test on the green with the same Cura profile as the white and problems immediately showed up. I’m thinking that somehow the pigment is changing the filament just enough to cause issues. These gaps are showing up on the first layer. The top layer isn’t pretty, but it’s not like this.
Before I start running through the green PLA, are these gaps caused by underextrusion? I notice that they only appear on certain parts of the print, while other parts look good.
Ideas? Thoughts?
Full print (outer diameter about 4 1/2 inches, with of printed part is about 0.2 inches)
Was this the underside or topside?
Seems like underextrusion.
I had something similar caused by my bed wobble, but I know there are other causes like temps, esteps, pla that’s too damp, etc.
The problem is occurring on the underside, that is, the side that is in direct contact with the bed.
First two pictures are scans of the underside, last two pictures are scans of the topside.
Can you share better picture, higher resolution?
What build surface are you using?
Consider upping the extrusion multiplier a little.
Consider upping the nozzle temp just a little.
For major changes in filament you could potentially need to tweak the first layer height, temperature, retraction, and linear advance by their recommendation.
In your specific case since you seem to be having problems on the first layer perhaps start with verifying your first layer is printing perfectly.
Different colors of the same exact filament will often require different nozzle temp.
Some of it what is used for the pigment. Some of it is due to heat absorption and emissivity due to the actual color.
Generally white will need a higher temp than black.
You might want to try a temp tower to figure out the optimal printing temp.
I personally have found that I just have to change nozzle temp when using different filaments where the only difference is color. Maybe I’ve been lucky.
That doesn’t mean that your problems aren’t being caused by under-extrusion. You have calibrated your extruder?(i don’t think that was asked)
-S
So I ran a temp tower, and the best quality is around 205 C, which is the temp It’s been running with both the white and green filament. Played with the flow, upped it to 130%, not much difference, changed the first layer height from 0.2 to 0.24mm, not much difference.
Yes, I have calibrated the extruder, one of the first things I did after setting up the printer.
Here’s what a good portion of the print looks like (texture apparently is from the bed).
Here’s a poor attempt at showing the line pattern in Cura with what the print looks like. Where the lines are short, the problem doesn’t occur. Where the lines are long, the problem occurs.
By watching the print head very closely, I have been able to determine that the issue is due to the previous line (not layer) of PLA getting plowed as the head moves to the next point to begin printing the next line. This became apparent when I changed the first layer to concentric, as it was difficult to follow the print head when in ZigZag mode (bottom pattern initial layer). To a certain extent, a second layer fills it, but there are still scars.
Thanks for all the ideas. Now if I can just figure out how to prevent it from plowing during moves to a new start location.
