New i3V owner: A few beginner questions

[DanSilov]

Ok, it's time to return to my so far not so great 3D-printing efforts. Thanks again to everyone for their advice. Let me try to go one by one with answers and then also share some findings of my own.

1. I've checked the assembly of pretty much everything, and the one problem I found was that extruder block tilted slightly to the right (side with the motor). I could even tilt the block with my hand a little, so it was definitely something to improve. After I tightened eccentric bolt, the block now seems nice and tight, although it does look a small portion of degree out of perpendicular state.

2. I'm not sure how to check belts tightness. They seem rather tight to me, and there's no skipping or anything of sorts. Y-idler belt is not rubbing the wood bracket, but X-idler belt does stick to one side and touches the wood there. I'm not sure how to adjust that.

X-idler belt rubbing the bracket
IMG_8248.jpg

3. It seems to me that I have a problem with the heat from extruder motor. It gets so hot during the 1-2 hour print, that I literally can't hold my finger on it longer than 0.5 second. The voltage is set to 0.37v. My original gear small deformed badly (see the picture below), and that was probably one of the reasons I couldn't get proper results after calibration. But the main extruder part was also a bit blobbed out of the box, I couldn't fit the guilder on it, so I had to use a knife to take some plastic off. As I've printed extruder myself, although the print was very bad quality, it was of a correct size, and after calibration it gave me correct extrusion results.

Original deformed gear
IMG_8244.jpg

4. But after some time (maybe 3-4 small prints), new extruder started to deform as well. Not sure, whether it's because it is related to bad print quality, heat from the motor, PLA as the chosen material or something else. Despite this deformation (see below), it does continue to produce a much better results than the original extruder. I've printed another set of extruder parts, and some smaller things, and most of those look good enough. Although visible mesh on top layer is still present at places and some side blobbing occurs.

Deformation of the new extruder
IMG_8247.jpg

New printed knob
IMG_8249.jpgIMG_8250.jpg

5. I figured out that problems with PLA adhesion only occur when I reverse the fan air flow to blow air out of extruder. If airs blows into extruder, most of it also cools the print a little, and I never have any issues with prints sticking to the glass, even without using any spray or blue tape. I can't even remove finished prints from the glass unless it cools down. What also helped, is the settings that printbus uploaded. I use "brim" setting there to add a nice 2-3mm brim around every print.

6. I've checked the voltage of my ATX power block, and it is exactly 12v.

7. Humidity in the room I print in is around 40%, and since it's quite hot these days here, I turn AC on as well.

8. If my nozzle it hot and waiting, plastic continues to extrude a little for some time. Not sure if everyone has this, or maybe it's one the problems I'm having.

9. I do feel there's an issue with slicing. If I compare bottom pattern of the original extruder parts and the one I printed (plus a couple of just first layers), it is apparent, that my lines are much thicker and there are fewer of them. If it's the case it might explain some mesh issues I'm having – where top lines are expected to be thicker than they are, so they are extruded with a greater distance from one another, producing the mesh. (photos are in the next reply)