Layers Sagging When Printing

Hello,

Was wondering if someone can give me some kind of advise as to why some of my layers keep sagging when printing? I usually set the layer height for a lot of my prints at .30mm and use ABS filament.I also set the feed rate at 80%, extruder is at 225 degress and the hotbed is at 110 degrees. I've noticed that when trying to print finer details that the layers kind of sag and the layers don't mend properly. I'm wondering if this has to do with not having an enclosed case around my MakerFarm 8" Prusa i3v or maybe it has do something when not having my fan properly placed on the extruder. I still haven't printed out any kind of piece to help direct the air flow for the fan and I think that this might be an issue as well.

Please see the attached images to get a better idea of what my prints look like and the way my fan is set on the extruder.

[i.imgur.com]
[i.imgur.com]
[i.imgur.com]
[i.imgur.com]

Please let me know if you guys can offer any advise as I'm still new to printing. I appreciate anything I can get, thanks!

Edited 1 time(s). Last edit at 02/15/2015 05:52PM by rpartovi.

Your struggles there are bridges (where a layer of material spans what was a gap between two sections of material in the previous layer) and overhangs (where the material slopes out over air on subsequent layers) and there's a lot of material on them if you search.

For starters, though, 110 is far too much bed temp for PLA (for a PLA part that size I'd probably use 45 and I've never seen the need to go over 55) and 225 is pretty high for it as well. You can also slow down bridges which may help.

PLA also likes a fan for part cooling. That's not the fan in your picture, which is a hot-end fan, which keeps the heat from the hot end from traveling too far up into the heat break and causing nozzle jams.

Edited 1 time(s). Last edit at 02/15/2015 01:14AM by IMBoring25.

Realized I accidentally wrote PLA instead of ABS. I just edited my original post.

OK, those temperatures are better in range for ABS but you can still try lower temps and slower speeds for the bridges.

You can see how low your material will easily extrude by turning off the motors and turning the extruder by hand as you adjust the temperature. Then you can see how print quality is affected.

You also have the option of configuring support material but that will involve some post-processing, more so if you only have one extruder.

I would think that if a bridge line breaks you slow down but if it sags you speed up? No? I would crank up the bridge speed 20% or so.

Thank you so much for the suggestions! I haven't tried messing with the bridge settings yet so that is something I will start looking into.

I've also been running into another problem I was hoping you can maybe help me out with. When I start my prints the beginning layers that are extruded come out very light and thin. As more layers are being put down the layers start coming out normally again. I've done this with 3 other prints so far and I keep running into the same issue. I took apart the extruder and cleaned out all the debris and just made sure that it was being rotated properly to be fed correctly. After doing this I keep running into the same problem. I've even tried just heating up the hotend and extruding filament to see if it was clogged but it was coming out alright.

Please let me know of any suggestions on how to fix this issue.