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aidtopia

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Everything posted by aidtopia

  1. After taking a break, I tried again. This time a print failed partway through with a temperature sensor error. I replaced the temperature sensor. That was challenging since I couldn't use the change material process to unload the filament because the printer won't heat the head when the temperature sensor has failed. After working through that issue, I loaded fresh filament, re-leveled the bed, and tried again. Nothing extruded. So I used the atomic method to do a hot/cold pull, which worked perfectly (so the new sensor seemed to work correctly). My next print attempt failed to adhere to the build plate. It probably had dust and skin oils from all the repair operations. So I thoroughly cleaned and re-prepped the build plate with glue stick. But when I went to re-level the bed, I couldn't turn the printer on. No fans, no LEDs, no display. I checked the power connection and found it secure and in the correct orientation. There was a periodic --click-- about every two seconds, like the sound of a relay, from inside the printer (not the power brick). The clicking stopped when I flipped the power switch off, and resumed when I flipped it back on. So there's _something_ going on. I assumed a fuse or breaker in the printer had cut out, but the documentation gives no indication that the device has such protection. So I'm guessing a voltage regulator on the main board has died. It seems replacement boards are hard to find. (I'm in U.S.A.) The distributor I originally bought the printer from (fbrc8.com) doesn't have any. The only one that I found online is rather expensive.
  2. The silicone oil made a world of difference. I got 2 hours into a 4 hour print without any filament sticking to the nozzle! Unfortunately, that's when the temperature sensor failed. I'm sure it's unrelated, but I think it's final sign that it's time for me to give up on this printer.
  3. Those nozzle socks are interesting, but I think the real gem in that thread is wiping the nozzle with a little silicone lubricant before printing. So thanks for pointing me to that!
  4. A lot of my print failures stem from the extruded filament sticking to the exterior surface of the nozzle instead of the previous layer (or the build plate). Is there something I should be doing to the nozzle on my Ultimaker 2 to prevent the extruded plastic from sticking to the nozzle? Sometimes, during the initial extrusion at the beginning of a print job, the filament will make a mid-air u-turn (driven by the fan?) and attach to the side of the nozzle. Sometimes the skirt or brim lines will go down perfectly, but the filament starts to accumulate on the nozzle when putting down the first layer of the actual object which might have sharper corners and tighter radii than the skirt or brim. Sometimes it starts much later, often when there's a retraction before a travel move, or when the nozzle touches a bit of stringing that sticks up from a lower layer. Whenever it starts, the problem quickly becomes catastrophic. Once you have a tiny bit of plastic on the outside surface of the nozzle, all other plastic in proximity will stick to it. Before I know it, it's infiltrated the fan bracket and encased the heater block in plastic. I've tried heating up the nozzle and brushing off residual plastic with a brass brush and even replacing the nozzle a couple times. But it continues to happen frequently. Is there some lubricant or solvent I should apply to the exterior of the nozzle?
  5. Thanks, but the problem is not always about bonding with the build plate. It's that the printer fails one way or another for long streaks, and then, inexplicably works perfectly for a long streak. I have literally tried scores of recommendations designed to address whatever the latest failure appears to be from. As far as I can tell, those are all based on superstition as none of them has ever gotten me from failure to success. It's just years-long streaks of one mode and then--without changing anything--it switches to a years-long streak in the other mode. Since my original post, I've had at least 20 consecutive failures and no successes. * I had to replace my Olsson block again, because, after cleaning up the one encased in plastic, the stem of a new nozzle snapped off in the block as I was hand tightening it. (I was only hand tightening because I haven't been able to print the torque wrench tool you're supposed to use.) * I've had no filament extrude--done a hot/cold pull which looked perfect--again had no extrusion--done a second hot/cold pull which also looked perfect--and then the filament flowed again. * I've had the material removal operation leave a blob of stringy filament completely blocking the middle of the bowden tube. That required completely removing the tube and clearing the blockage with compressed air. * I've had the initial extrusion that the Ultimaker does before it begins a print make a mid-air u-turn and climb back up to the nozzle. A lumpy blob of plastic surrounding the tip of the nozzle is not conducive to getting the first layer to adhere to the build plate. * I've also had _perfect_ first layers, only to have the extrusion for the second layer prefer to adhere to the outside of the nozzle rather than the first layer. * And I've had lifting and warping begin two hours into a print. I've complete detachments from the bed happen near the end of a print, and I've had prints that split. * Retractions before travel moves never seem to be enough to avoid scars and stringing and yet they are more than enough to lift long beads of filament that has already been deposited, which then drag around the print building up like katamari damacy. If I were having the same problem time after time, and I got some advice that helped, I think I could stomach this, even if there were still occasional failures that happened at random. But the very long streaks of failures about which there seems to be nothing in my control to fix is disheartening, especially knowing that the printer is also capable of long streaks of success.
  6. I bought my Ultimaker 2 in 2015. My first print, the Ultimaker Robot, lacked definition and symmetry. At first, I could never get a good print. Adhesion problems, warping, unreliable dimensions in along all three axes, sagging, etc. Within weeks, I had my first hot-end-completely-encased-in-PLA catastrophe. There wasn't much help available online back then, and the support folks I talked to hadn't ever seen that problem before, so they couldn't quite understand what I was describing. After about a week, I finally freed the hot end from the giant blob of plastic. For several more weeks, it was endless print failures--not just bad prints--but useless blobs of plastic. I tried all of the advice I could find on the internet, including the suggestions that contradicted the other suggestions. But nothing seemed to make a difference. And most of that advice was about making small improvements, like reducing stringing or a little warping. Very little information about dealing with flaws at the scale I was experiencing. I had splurged on the Ultimaker, because I'd wanted a tool, not a research project. I wanted to make things, not learn how to tune a 3D printer. I lost interest in 3D printing for a while. From time-to-time, I'd give it another try and get a few crummy prints before another complete failure or blob-encased hot-end. Almost four years later, I tried again, and suddenly, everything just worked. I still cannot explain why because I hadn't changed a thing. Default slicer settings and printer temperatures. I was still on the original spool of filament that had loaded into the printer since I'd unboxed it years earlier. Stranger still, the printer continued to churn out successful prints. I started printing more and more. I began to trust that if the first few layers went down fine, I wouldn't have to babysit an entire three- or four-hour print job. When that first spool ran out, I dreaded having to load a new one. To my surprise, I got even better prints with less stringing. I was able to clean and relevel the build plate and still get good prints. I used up several kilograms of PLA prototyping and making things that I actually used. This was the dream of 3D printing. I've never been able to explain how it went from always failing to always succeeding, but a long stretch of successes made me confident enough that I could depend on the printer. And then, after more than two years of zero print failures, I entered a new streak of nothing but failures. And, once again, I have no explanation for what changed. A four-hour print I'd run in the morning was fine. But the same printed started in the afternoon ended up missing most of the upper layers even though the Ultimaker screen said it had finished. It turns out the feeder ground away so much filament in one spot that it could no longer advance it, so even though the printer had gone through the motions, no plastic had been extruded. After fixing that, the next two prints detached partway through, leading to two more encapsulations. One had so much plastic inside the fan bracket that it took two days to remove it from the print head. That particular design flaw had always bothered me. A simple failure (print detachment) becomes a literal hot mess. I finally ordered an Olsson block after seeing how the nozzle tip extends farther below the fan bracket than the original integrated nozzle and header block design. The Olsson block was relatively easy to install, and I got exactly one good print out of it: The Ultimaker Robot. After seven years of using an Ultimaker, I finally know what one is supposed to look like. But the very next print, whose first 10 layers I patiently watched go down perfectly, later lifted dramatically at all edges and not only warped but turned blobbish. I shrugged it off as a fluke due to bad adhesion. I re-leveled the build plate and restarted the same print job. Again, the first 10 layers went down beautifully, but when I check on it 30 minutes later, the entire print had detached and my shiny new Olsson block was mired in a blob of plastic that been scooped up by the stupid fan bracket. Once I clean that up, maybe everything will work flawlessly again. But maybe I'm due for another year or two of endless print failures. There's no way to know. How do you motivate yourself to keep trying, when you don't even have a hypothesis of why you sometimes get a long streak of success and sometimes get a long one of failure?
  7. Thanks! Enabling "print thin walls" setting improves things with the standard version. I'll try the Arachne engine soon.
  8. Using OpenSCAD, I've been putting some raised text labels on my designs. When I print them with my Ultimaker 2, the text is often has gaps. I thought this was a printing problem, but I recently realized that the slicer is dropping parts of the text. I assume that's because these parts are very small. Are there Cura settings that control which small features are skipped? Here's an OpenSCAD script that illustrates the problem by generating a string of digits in the Arial typeface at sizes of 2, 3, 4, and 5 mm. module sample(size=10) { cube([8*size+2, size+4, 2]); translate([2, 2, 1.9]) linear_extrude(2) text("0123456789", size=size, font="Arial"); } for (i=[0:3]) { size= i + 2; translate([0, 14*i, 0]) sample(size=size); } The attached photos show how OpenSCAD renders the STL and how Cura is slicing it with the normal profile. The 2mm text is missing completely, which seems reasonable. The 3mm text is also missing, but the slicer instructs the print head to travel to where it would be. At 4mm (which is the size I keep ending up with in my designs), the text is mostly present, but the figures are broken: the diagonal from the digit '4' is missing and the curves at the tops and bottoms of the round digits are broken. At 5mm (and above) the text remains intact. I've tried using the Fine and Extra Fine profiles, but those mostly just change the layer height, which is not the issue here. I've tried to search for settings related to small or fine features, but I haven't found any that seems to affect the slicer's behavior in this regard. In many cases, I can increase my text size, but, when I'm constrained to a slightly smaller size, are Cura settings I could adjust to reduce the skipping of the fine strokes of small-ish text? Thanks.
  9. Thanks for all the replies. I don't think there's a problem with the teflon isolator. The under-extrusion seemed to be related to the gunk clinging to the nozzle itself. Now that it's cleaned up, I'm getting good prints again. Next time I go atomic, I'll try a lower temp.
  10. No Olsson block. I seem to have found the problem and the solution. Once there's a bit of PLA on the outside of the nozzle, the new PLA really, really wants to join to it. I solved the problem by cranking the nozzle temp up to 260C for a few minutes to melt the plastic that clung to the outside and tugging at the drips with some needle nose pliers, being careful not to nick the nozzle with the tool. This removed most of the PLA that had adhered to the nozzle and now the newly extruded filament moves down as gravity would seem to dictate. Of course, during the Atomic method, you set the temp up to 260C, but it was never at the temp for very long, so it wasn't enough to melt off the bit that clung to the outside of the nozzle.
  11. I've been printing successfully for almost a year, but now I'm having trouble getting the bead of filament to adhere to the build plate. The filament seems to be coming out thinner than normal, and it immediately curls up and adheres to the outside of the nozzle. I have tried each of the following, multiple times: 1. Re-leveling the build plate. This includes attempts to position the nozzle both closer to the build plate (by adjusting until there's more resistance than usual when sliding a sheet of paper between the nozzle and the build plate) and to position it farther from the build plate (by adjusting the screws just shy of the resistance point). 2. Going atomic to make sure the nozzle has no obstructions--the cone comes out very clean and well-formed. 3. Slowing down the speed for the first layer. 4. Changing filament (from and older spool to a fresh one). 5. Cleaning the build plate and re-applying fresh glue stick (as I've done successfully many times in the past). Same problem in every case. The filament comes out thin and defies gravity, preferring to curl up and cling to the nozzle rather than be smooshed against the build plate. Suggestions? I'm at my wit's end.
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