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Re: Orcinus' Build Log (was: Thermistor insanity)

PostPosted: Thu Jul 19, 2012 11:08 am
by orcinus
This is about as good i could get the black UM PLA to print before i ran out of it:

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Ignore the dodgy infill.

The important bit are the "holes" in the perimeter. For some reason, the flow of plastic gets interrupted at odd points.
Could the gaps be caused by the moisture in the filament?

Re: Orcinus' Build Log (was: Thermistor insanity)

PostPosted: Thu Jul 19, 2012 12:28 pm
by orcinus
Forgot to mention... That was at 200 deg C.
Anything below that was unusable. Plus, i've noticed the extruder was starting to push the hotend insulator towards the platform on anything but slowest extrudes. At 200-210 deg C, it was fine, though (apart from the leak).

I wonder how the white UM PLA is going to behave.
Initial tests show it sticks to the bed much much easier, and extrudes more or less stable at 190-195 deg C.

Re: Orcinus' Build Log (was: Thermistor insanity)

PostPosted: Thu Jul 19, 2012 10:20 pm
by Enraged
I ordered some PLA from Voxel Factory in Montreal to see if the filament is the main issue. Worst case is I have more filament and the same problem.

Re: Orcinus' Build Log (was: Thermistor insanity)

PostPosted: Fri Jul 20, 2012 12:54 am
by orcinus
Fingers crossed it's the filament for ya.

So far, the white UM PLA is behaving much better. It extrudes at 185 and doesn't generate gaps and holes like the black.
I'm getting no weird residue nor leakage either.

However, i'm getting a whole 'nother set of problems. As long as i extrude thin walls or perimeters only, everything's fine. The moment i start extruding something with infill everything goes pear-shaped. I've been printing myself some angle brackets (35 degrees) so i can mount the fan pointed towards the bed instead of blowing directly at the hotend. I've been tweaking the width-over-height manually in Slic3r and when i increase width to 2.5-3.0 times the height, i get nice clean M3 holes in the brackets and relatively even walls. But no infill - it doesn't fit, because i've made the brackets 2mm thick. If i decrease WoH to 1.5-2.0, i get nicely filled out insides but the walls look like a wobbly mess.

The thing i've noticed is this - as long as i extrude long straight wall sections, the layers are almost perfectly even. I get just a little wobble from the threaded rods, but that's expected. The moment it gets more complicated than that, the layers become totally irregular.

I'm sort of guessing it might be the hotend. In particular, i think i've screwed it up with the black filament and now the pressure is high enough and the wooden clamp cracked and weak enough that the whole hotend floats up and down as the pressure rises and falls, perpetually changing the distance from the nozzle to the previous layer.

'Cause the thing is, i've noticed that irregularities in layer height vary with extrusion demand for that layer - if there are holes in the current layer, causing the extrusion to stop and start, i get wider layers (meaning more squashed, meaning higher pressure). If there's a lot of fill in the current layer, reducing the pressure in the hotend, i get narrower layers (less squashed). There are irregularities, of course, but the fact remains that long straight continuous extrusion sections end up perfectly, while anything with starts and stops and retractions is a mess.

Re: Orcinus' Build Log (was: Thermistor insanity)

PostPosted: Fri Jul 20, 2012 2:56 pm
by orcinus
A very ghetto printed fan angle bracket:

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Re: Orcinus' Build Log (was: Thermistor insanity)

PostPosted: Fri Jul 20, 2012 6:32 pm
by Enraged
it still looks better than my fan that is attached by zip tie haha

Re: Orcinus' Build Log (was: Thermistor insanity)

PostPosted: Sat Jul 21, 2012 12:26 pm
by frob
Enraged wrote:I ordered some PLA from Voxel Factory in Montreal to see if the filament is the main issue. Worst case is I have more filament and the same problem.
I've been using their filament for a month now - only been running black ABS @ 1.75mm so far, and it prints great. we've been using that to dial-in the calibration on my first Hadron, and have gotten some killer prints at 0.1 mm layers on models such as the now famous pink-panther woman statuette. At some point when there's more time we'll try to take pictures or video of it running and post that here. I have nothing but good things to say about that filament, although the traction with the makergear extruder its running in leaves something to be desired - this is limiting the print speed at this point.

Re: Orcinus' Build Log (was: Thermistor insanity)

PostPosted: Sat Jul 21, 2012 2:48 pm
by orcinus
Couldn't sleep (having a rough work week, my sleeping schedule is completely out of whack) and i remembered i had an 20x4 LCD left over from a project never realised (i wanted to make myself an intervalometer, but never did - ended up backing the Timelapse+ project on Kickstarter, so i probably never will).

Ah, who am i kidding... I've actually got stashes of LCDs and LED matrices all over the place. Although this was the only 20x4 one with a red backlight. Red backlight, blue ORDbot - it just had to be done:

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Re: Orcinus' Build Log (was: Thermistor insanity)

PostPosted: Sat Jul 21, 2012 4:23 pm
by Enraged
nifty!

Re: Orcinus' Build Log (was: Thermistor insanity)

PostPosted: Sat Jul 21, 2012 10:03 pm
by orcinus
Thanks :)

Heh. Maybe sticking it to the electronics plate with double-sided tape rated for 45kg per meter was not such a good idea, LOL
It was supposed to be temporary, while i check for contrast and decide whether to put a different resistor between GND and the contrast pin, then i intended to hotglue the rats nest on the backside of the display and mount it properly.

Unfortunately, it's now truly and verily stuck.
Think - "i'm afraid i'll break the PCB if i pull on it any harder" kinda stuck.