3D PRINTING - trips and tricks

INTERNET KNOWS

If you read on multiple occasions on internet that your 3D printing machine has a weakness,"it will not happen to me" will not go a long way. I was lucky to find that out in pretty basic situations. More than once I read that Cura has a problem with multiple objects. It does not concern me, my Cura can do it. Until, when I printed jail part of Sheriff's office, with two part lantern on same bed. Printer just skipped first two layers of jail and started printing the third in thin air.  Not a pretty site.

First two layers of the lantern neatly done (in the distance), and third and consequent layers printed in thin air

Similarly it could be read that SD card that comes with printer is junk you and should be thrown away immediately. It did not happen to me, until a lucky circumstance, almost at the end of the print, printer just stops, and on screen it could be read "no SD card". New SD fixed this issue.

Pert of the model not printed due to failed SD card

 And solution for missing part was easy wich lead as to next segment

PRINTUS INTERAPTUS

My printer lives in my bedroom. I`m a great lover of all technical things, but I just cant sleep with him working. So I try to take care of how long a piece would print,not to take time from my sleep. But, some times mistakes are happening. You are eager to have some piece of terrain, you do not pay attention, and happily start 20 hour print job  around 9AM. Around 11PM you start to think about other solutions. I found out that you can pull model in Cura below the bed, so it will slice only part above bed. With layer view, you can be pretty precise with your cut (layer or two give or take). I done it on Sheriff`s office and it turned out to be OK.

Lower part of  Sheriff's office

Top part under printing 

So, it could be done, but you have to find good place to do it, for example on the top of the window before bridging layer.

SOMEBODY ON INTERNET KNOWS
On previous pictures you can see that their is a problem with thinner elements, they are not printed very good. I tried to find help on two facebook pages and two forums, but apart for some vague answers about retraction, it was unsuccessful. But, on the fifth post on one of the 3d oriented terrain facebook groups, some guy mention "atomic pull". That was the first time I heard about that therm. I found out on Google that its the method to clean up the nozzle and PTFE tube of your printer. Fact is that PLA filaments are coming from various sources, and, sometimes inside the filament there is some dirt, pieces of other plastic or metal, or just dust could be found. Such pieces could stick to the inside of PTFE tube or nozzle, and slightly alter the volume of plastic that flows from nozzle. Alternation is so small that normal layers are printed without problem. Problem arises on start of printing, first layer or after retraction, as well as when printer is printing thinner layers (like support). Atomic pull solved that.
You do atomic pull by heating the nozzle (220-223 C), then letting it cool. When it cools to about 90-120C, you firmly pull the filament from the nozzle. Because the filament is almost hard on that temperature, it brings all the dirt with him. You have to repeat this procedure several times. I started with 110C and ended with fifth pull at 90C, progressively doing it on lover temperatures. Printing quality improved visibly.

Missed or under-extruded layers on thiner or separate parts of the model could be a sign of dirt in the nozzle

IT'S A MESS
When you take a look on following picture you will surely say that:

It is a mess

No, it is not. It is just the way Cura does supports sometimes :)