What I have 3D printed so far - and things that could go wrong during a print

Here are the things I have printed as I was playing around with the temperature and slicer settings.  On each print, I describe some flaws and possible ways to avoid them.

This twisted bottle was scaled to 60% but I think it was meant to be printed only at full scale because the threads and the the walls became too thin.  Before you scale a model down, you need to consider the width of the walls.  The print finished and works okay although the threads didn't run smoothly. You will notice the 2-tone color.  This is not a flaw but due to the white filament that was about to run out so I just spliced the beige filament.  I panicked a little since I didn't know if the splice was going to hold. Luckily, it didn't snag into anything and I finished the print. :)  I will make a separate post on how to splice the filament.

Here's the cuddling owls scaled down.  I forgot how big the original was but this is about an inch tall. This was printed hollow with 0.3mm layer height which is not recommended for my nozzle. I found out lately that for best results, you should print with a layer height that is about 80% of your nozzle diameter.  Maybe that's why it had some separation on the owl's head.  There's no question that you can get better prints on a smaller nozzle diameter but overall, I prefer a slightly bigger one to make prints faster.  By that I mean less slower :).

This is faceless scaled to about 50-60% and also printed hollow.  This is when I understood the need to put a fan or a blower directed at the print.  You need a way to cool the filament as soon as it was extruded from the nozzle so that it will be strong enough to hold the next layer.  If it is still too soft and the nozzle is already laying down another layer on top of it, it will not hold up and will ruin the details of your print.  I did not have another fan to blow on this so I blew air using a straw on the parts where it needs to be cooled while printing :).  You can bet I will install a dedicated fan someday but right now, whenever I use a fan, it cools my nozzle down too much so I'll wait until I get a better heater.

This is the stretchy bracelet. The one at the bottom was printed with 0.3mm diameter while the white one was printed recently when I was experimenting with resistors and after I drilled my nozzle to make it bigger (I will post the result of this experiment).  You will notice the gaps between layers and they were caused by bubbles which I have not totally figured out yet. The nozzle will sometimes make this popping sound and will cause the extrusion to skip. Some people suggests that the popping sound is caused by trapped air in the filament during production.  If that's the case, I don't have a way to prevent it.  When my new resistor and heater cartridge arrives, I will experiment with a higher temperature and see if the popping will disappear.