:-\ I continue to be plagued by a certain fairy who hasn't seemingly taken the hint. It's not all bad news though; I'll start from the beginning. Woke up this morning to this...
... the print run has obviously finished, but the print itself isn't (this is Printer 1 btw)! Has it also tangled at the rear like Printer 2? Did my careful planning fail to avoid what I was hoping to avoid...? Well, there wasn't any tangle at the back at all. That means the issue is in the print head. This was confirmed when I tried to load/unload filament through the motor extruder. It wasn't budging. So I stripped it down... aaaaand found this...
???
???
now I have absolutely NO idea what would have caused this to happen, although I have some suspicions. I'll get back to that. In the meantime, the only thing to do with this is strip the whole thing down and clean it out. Dreading it, coz inevitably it means heating up the nozzle to try and loosen / melt any melted filament stuck where it shouldn't be... cut a long story short, completely stripping it was just the ticket, the filament actually came untangled fairly easily once I had done that. There was still a largish section of filament stuck in the plastic piping leading into the nozzle, so that wasn't budging. Fortunately, there was a small bit of filament sticking out the end. I was able to get away with letting it sit in boiling water for a minute or so to soften it up, and then using needle-noses to wiggle it free. Came out nice and cleanly too. Made my life a lot simpler. Got the printer up and running again. You may recall I was going to do the last 2 pieces of Module D on Printer 2. Well, as a result of this mishap, that's now going to be the last 3 pieces! :
... as for Printer 2...
... it behaved itself overnight. Nice!...
... progress has slowed, but it continues nevertheless. Getting a better look at that failed print from Printer 1...
... you can see it stopped printing right near the end, and that the piece isn't usable! If they fail right at the start, fine, nothing too much wasted (except a bit of time). If they fail right at the very end it can also still be fine, if enough of it has printed. But to fail right before the point where you have a usable piece is a real kick in the teeth... :-\
... anyway, Printer 2 didn't want to load up filament properly this morning either. I had to strip it down as well to clear whatever was jamming it. Wasn't expecting to find anything to bad in there; the print finished successfully after all...
... a few strands and a small clump stuck to the spindle feeder. No biggie. I doubt whether this caused the issue in Printer 1; this kind of excess in the extruder only happens at the end of prints when the feeder is retracting the filament, and you get clumps of semi melted gloop coming back into the feeder from the hot-end. If it had been an issue, I would have known it at the very start of the print the previous day... anyway, while I was cleaning this out, I got Printer 1 going with the next job: Printing panel adornments, I started with these...
http://tardisbuilders.com/index.php?action=dlattach;k=-170;topic=8789.0;attach=185481;image
... one to start with to be exact, and a half hour later, I had this to show for it...
... awesome, worked as well as I could have hoped for. Unfortunately (I'm saying that a lot lately!), the back of it is really thin. Like, REALLY thin. I kind of "tore" it taking it off the print bed. I think it will still be usable though, but I realised that it was probably going to be better for these to print bare-back directly on the glass. As it cools, there will be different thermal expansion / contraction coefficients in play, and the panels will almost slide off the bed once it's cooled. The adhesion is just waaaaay too good to keep printing them on the blue tape... anyway, take a look... ;D
... sweet! I thought hanging around to change em every half an hour was a bit of a bugger though, so in addition to printing directly on glass, I also decided to print em in bulk...
... you can see lots of artefacts on these, they actually clean up fairly nicely (as you'll see
)... and to show you how thin these are...
... you can see through them! Actually, they don't even need to be help up to the light, I was able to see the floor in a darker corridor through it! This might be beneficial when it comes time to stick them to the modules; that they're thin means they're flexible, and given the comparatively large surface morphology of the modules, the flexibility of these will mean I can still get quite a lot of contact surface area...
... clean up alright don't they? ;D
ok... here's some more bad news. Just as I was starting to type this up, Printer 2 suddenly went "bang"; not like as in something blew up, like the gantry rammed into the side of the case. I had a look and something like that must have happened, because the head was now printing waaaaaay off centre. The printer was essentially extruding into thin air, offset by half the print size. I have no idea why it did that, but it effectively ruined the print; there's no way on my printers to re-zero the X and Y axes mid-print (which is silly if you ask me; being able to return to a known origin so you can recall your last position is a staple of any kind of commercial CNC manufacturing operation. I DID buy very, very cheap printers though
:-\ )...
... so... here's the failed print from Printer 2...
... look familiar...? It should...
... here it is, side by side with the failed print of Printer 1 from this morning. The same piece off printer 1 from this morning. Stuffed up in almost exactly the same spot on the same piece from Printer 1 from this morning, at 92% completion! Maybe this piece is cursed?
:
... yeeeeah, not buying that either. If it was a problem with the print file / model file, then it would have errored in exactly the same spot, and cause the same reaction on both printers. This is just a really, really, REALLY unlucky coincidence. An annoying one too... so, I've once AGAIN started the bottom front section of Module 1D on Printer 2; we'll see what happens...
... as to what happened with Printer 1 and why the filament decided to play ring-a rosie inside the spindle area, I noticed today as Printer 1 was working that the front fan on top of the heat exchanger wasn't really working properly; it needed a few nudges to get going, and was then really sluggish. It's possible that during the print last night, the fan seized and stopped, causing the rest of the print head to get hot. Filament may have melted inside the spindle area and just started to clag up the interior rather than feeding through. That's my best guess anyway...
... the annoying thing about these print heads is that, while a lot of the bits are reasonably modular, the fans are not! It would be simple enough to have a plug attached so you could swap them out if something happens to one. But no, these are wired and bundled aaaallllll the way back to the main controller / PCB. So, I'd either need to cut the wires and attach another fan using some solder and heat-shrink (something that I'm not particularly experienced at), or swap out the whole head assembly for a new one. That's about $150.00 investment and a 1-2 week wait from China (I've used all my spares). I'm going to press on in the same manner I have been doing today; short run prints for Printer 1 until I can fix the problem properly...
... also about 20 minutes ago, the next lot of panels finished on Printer 1. I found printing 6 of them was a little hit and miss in terms of the quality, so I reduced it to 3 at a time. One more batch like that, and these panels (I call them Roundel Panels... y'know... coz they have roundels on em
) will be done. Just 3 more sets to go after that...
... ok, probably talked your ears off for long enough now... will post again after the next significant prints are done...!
D.
