Solved solid layers breaking open

Hello,

I'm printing a hook to hang some skateboards on my wall, but te second solid layer (after the 0,25% layers) breaks open like a person with sunburn. The picture will probably give you a better indication of what I mean. Does anyone have any clue why it does this? It's not the first time it happens, and although this print only takes like 1,5 hours, it would be nice to cancel these little errors out.

So if anyone has any ideas, I would be glad to hear them.

Thanks in advance!

 

it looks like you may be too hot. try to increase the infill but abit to give the layers something to stick to and decrease the temperature by 5

 

Thanks for your reply

I'm currently printing at 210 C(PLA), I'll try it a few degrees lower. I don't think that the infill has anything to do with it, because the first solid layer (on top of the infill pattern) is perfect

 

Printed it while using 205C gave me the same problem. Is this still to hot, or could it be something else?

 

try it cooler and see if it gets worse. then try to go hotter. its trial and error really. i had those issues and they were related to my temps being to high so thats why i am suggesting temps

 

Just be aware the minimum extrusion temperature in the firmware is 195, best to modify that or do 197

 

Thanks for all the fast responses!

I just printed some empty cubes with different temps, but I don't see much difference, just that everything below 200C doens't connect the layers completely. 205C is, as far as I can see, the best, wich would rule out that it's a temperature problem. I tried to find the perfect temperature with this clip:

Am I doing it wrong, or could it still be something other then the temperature?

EDIT: below 185C was just not printable on my machine

 

I've never really seen that but it sure looks like something caused by being too hot to me.

Try a cal cube instead of the empty cube.

 

Alright, just spend a few hours printing cubes (2x2x2cm) with a infill of 25% and 1 perimeter (I was hoping to see a clearer difference with 1 perimeter). Ultimatly, it looks like 218 C looks the best so far. So, as much that I would like to say: "Wow, my print quality is so much better now that I'm printing it at a lower temperature." That's just not happening... So, I think that I pretty much rulled out the possibility that the temperature is to high.

I have no idea if it has anything to do with it, but as you guys all blame the temperature, could it be that my fan isn't cooling the print fast enough? Or, a much more likely scenario (because I only see this for the first time, and not on the small prints) is it cooling it to much? I could probably test it by printing the whole hook again without the fan, but I was wondering what you guys have to say about my "theory". And ofcourse, because it's saturday evening and I do not hate my social life enough to sit at home on saturday evening, waiting for a print to finish.

So, if there is anyone who can help me further, or has a idea on how to fix this, feel free to answer here, I really like the responses of you guys.

 

^^thanks for the response, I also thought that it might be the thermistor. I'll try to score a deskfan of something like it and see if that helps. If it does, I might try to install a larger fan on it (thought I've seen some designs on thingiverse for that). I've enough PC fans laying around here, so that won't be a problem.

I hope I can get a fan on my desk by tomorrow, I'll keep you updated on how that works out.

 

What layer height? How many top/bottom layers?

I highly doubt there's anything wrong with your thermistor. Since they're NTC if it read high at temp it would read high at ambient. More likely that it would read low from poor contact than it would read high

 

I think that I used these settings on the hooks:

layer height: 0,4 mm
infill: 0,25
Top and bottom layers where both set to 3
the second top layer didn't attach to the first, end the third is only halfway done because it was hitting the layer below that (I stopped the print)

The temp test was with layer height 0,2 and the other settings where pretty much the same

 

Yeah, I know, but this was more to check out the sizes end stuff, it didn't need to look good etc.
But adding more top layers won't fix the problem I'm having, because the problem occurs with the second top layer.

 

I think that I wasn't clear enough: I stopped the printing because the third layer was hitting the second layer. (which was already standing up when it started printing the third) I was hoping that the third layer would push it down enough so it wasn't noticable, but when that didn't work, I imediatly stopped the print because I was afraid that my extruder would die because of the impacts.

 

0.4mm layer height won't work. That's way too high. Even 0.3mm is pushing it for a 0.4mm nozzle.

Usually buildup on the first couple layers is a result of being too low on the first layer.

Either that or your Z steps per mm is wrong.