Hi folks.
All of the sudden my parts have a strange inside warping at the bottom layers.
Looks like someone carved a bevel around it.
I printed this filament a lot and i changed nothing on the print settings.
It just happened from one to the other print.
Can this be heat shrink? (part is printed with 100% infill, but 30% infill looks exactly alike)
cheers,
Christian
You can try to level your bed again.
Looks to me, that the first layer is printed too low resulting in a bigger extrusion with. After a few layers it compensates it. That makes the first few layers look bigger than the following layers. Because these first few layers are thin and bigger than the object to print, they tend to warp up a bit.
But keep in mind: Warping depends not only on your settings and your filament. In depends on the object you are printing, too.
Another factor could be room temperature.
Hi cantax.
Thanks for your reply.
The first layer is bigger because ididn’t reset my layer height after finally leveling my heatbed.
It is set to 0.3mm, the rest is 0.25.
There is no warping up.
The edge you see in the print is arest fraction of the brim.
The warp goes to the inside. Like someone carved acound the base layers with a spoon.
The part itself can’t be the issue, as i recently printed 2 other with the same result.
But i found it is less heavy if i enable cooling from first layer. That’s why i think it may be shrink.
What i don’t understand is that it happened all of the sudden, and why it has this rounded shape.
Maybe it is the filament. I am near the end off the spool. (Yellow abs 220ºc/100ºC)
I thought you were printing pla.
I’ve got no experiences printing abs.
Everything i can say would be purely theoretical.
Maybe it shrinks because your room temperature is too low or it is just not that easy to print abs without a closed chamber. I never tried abs, but i read a lot about it. I don’t think you can print abs without a closed chamber without warping. Even if you do everything right, you can’t get the warping problem to absolute zero.
I didn’t meant what layer height you chose in your slicer. What i meant was the bed leveling using the Z-Endstop. Well, how can i say it. It looks there is not enough space between bed and noozle. You set it up to 0.3mm first layer height and your printer extrudes enough to print a 0.3mm layer, but actually the space is just 0.2mm. That causes your first 2-3 layers getting too big. Because the following layers compensates it you got 2-3 layers very thin and bigger than your object. Like you would print a little brim around it that warps up.
Well, but if that assumption was right, why did all the parts i printed before with the same settings and material turn out nice,
With almost unnoticably upward warping only at the outer corners?
And why does it first shrink inward (from the desired outer dimensions) about 2mm over the first 5 to 10 layers
and then back out over the same distance? (to the desired outer dimensions)
Looks like that part had designed in a groove all around it. Bottom layer didn’t lift at all.
I fact it was hard to get off the glas plate. 
The bes is nicely leveled.
I just didn’t remove all brim from the print.
Look at the lower right corner of the second image.
There you can see the first layer is almost unnoticably higher than the rest.
This just a guess
It looks like the plastic started cooling very fast as the layers got higher and then stopped
Did your AC or some kind of fan turn on mid print then turn off for the rest of the print?
Like I said just a guess but it looks like something made the plastic shrink.
[quote=“Wrong Way”]This just a guess
It looks like the plastic started cooling very fast as the layers got higher and then stopped
Did your AC or some kind of fan turn on mid print then turn off for the rest of the print?
Like I said just a guess but it looks like something made the plastic shrink.[/quote]
That’s what i assumed too, but i had the fan off all time.
I strangely finf the effect is less if cooling is on from first layer X:(
Very strange…
Now i’m completely puzzled!
I just left the printer alone for the night and printed a new part this evening.
All the same material and settings, and :
IT’S GONE!
Quite strange … X:()
Could it have been caused by some air draw, open door or window?
Nope. No open door or Window and 26ºC room temp.
Hi Christian,
It is indeed a strange behaviour, I thought it could be the heat coming from the bed flowing around the object which at certain spots of the heatbed is higher causing the lower layers to melt briefly.
I also noticed a specific hotspot on my heatbed were always one corner of my printed objects curls upwards. The heatbed temperature seems not consistent on all spots. The temperature is measuend in the middle, but the outer part of the bed seems to get warmer.
I now print on tape,which seems to prevent this perfectly as it also is a kind of heatshield.
Cheers,
Guus
Well, whatever it was, it’s gone…
My heatbed heats quite even, as i put thermal compound between pcb and glass.
That made the heat spread more evenly.
For pinting abs i use 90ºC bed temp and hairspray on the glass.
Sticks quite well. I only get curlup at the outer edges of the bed on very large objects now.
Ok another guess.
I’m sure when the PLA or ABS is being made they don’t babysit the process.
Do you think it’s possible that there was a thin section less the 1.75 or 3.0mm I forget which you use in the plastic.
Hope you understand what I’m trying to say
Yes, i understand Wrong Way.
But if it was uneven filament it wouldn’t have appeared in 3 different prints all at the same place.
Spooky …
Good point.
That is very weird.
Is your printer haunted?
Maybe … LOL
