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Everything posted by geert_2

  1. When reading 3D-printing forums, and based on my own experience, the problems that do arise most in 3D-printing are related to: - underextrusion due to teflon coupler worn out, - underextrusion due to filament wound too stiff (works like a spring) and its bending radius being too narrow (high friction in bowden tube and nozzle), - temperature too low or too high for a given filament or model, - speed too low or too high, - dirty nozzles, - cheap filament with varying diameter or included debris, - bonding problems of model to build plate, - build plate incorrectly leveled, - etc. I d
  2. I usually design any supports by myself in the CAD program. Image: support test: trying various distances of support to overhang. Ridges are 0.5mm high and 0.5mm wide, separated 1.0mm from each other. Vertical gaps are between 0.2mm and 0.5mm, as indicated. Designing my own supports makes it easier to adapt them to the specific model: - For large areas, I want a bit more distance between the support and the model, so it is easier to peel off, e.g.: 0.4mm. - For small and high detail models, a distance of 0.2mm works fine for me. This gives a rather smooth underside on the overhang, much
  3. First clean the build plate with luke-warm clean water only, multiple times. No soap, no detergents. Then gently wipe the build plate with a tissue with very salt water. Yes, salt. Gently keep wiping until it dries and leaves a thin mist of salt stuck to the print bed. Then print on a heated bed at 60°C. I would recommend printing with the biggest surface downwards, as in the second photo. When hot, the model should stick rock-solid to the bed. After cooling down, it should pop off without any force. For me, this "salt method" has worked very well for over a year and over a 1000 models now, o
  4. I guess you already did this, but just to make sure: could you verify in Cura that the checkbox "Enable retraction" is checked indeed? Then verify in Cura, in Layer view, that extraction is active (=small dark blue vertikal lines). It could have been disabled accidentally, or on purpose to try something, but that you have forgotten to enable it again? Geert
  5. Is it possible to install (and uninstall) different versions of Cura in parallel, without them influencing each other at all? Thus also without automatically importing any settings? I could not find any info on this in the manual or FAQ. I would like to try the new versions, but without messing up my working version (Cura 14.09, on Windows 7 Pro, SP1), which I need for production of prototypes against deadlines. So the existing setup should remain stable, even though it may be "old". If not possible, what about adding it in future versions, For example by offering the following radio-button
  6. If the problem is that in mid-print, the print bed suddenly moves down, but the printer just keeps printing as if nothing happened, then this could be caused by the motor drivers (amplifiers) getting too hot. Then their temperature protection activates for a few moments, so the stepper motor gets no more current, and the built plate falls down a bit. There has been a recent post on this in the hardware section: https://ultimaker.com/en/community/20998-ultimaker-2-motor-drivers-overheating Could that be what you are seeing? Geert
  7. That is really cool. I am actually surprised that it works without leaking everywhere between the seams, on this small scale. Geert
  8. - I would prefer the list of posts (and the lists of forums) to be more dense, thus with less vertical white space in between them. And with more items listed on one page (or maybe user-adjustable in our profile?). So that it is easier to get an overview. The amount of information that is presented per item is okay. - I really don't like the blue pop-ups jumping over messages before I am logged in. These days a lot of people surf by opening in the background 20 posts from a list, by middle-clicking each. So, then I have to close that same blue pop-up 20 times, if I forgot to login first. Thus
  9. My first thoughts: - Something is scratching the case, as neotko says. - Or something is stuck between moving parts (slide blocks or wheels) and the case. - Or the rods and slide bearings are so terribly dry that they can't move at all, and start making a screeching sound. Like in cheap cheap computer fans, with worn-out bearings. But here on a lower frequency. If the rods feel totally dry, try gently lubricating them (but don't pour oil on the rods; do the oil on a tissue, and use that to genlty wipe the rods). - Or some debris got into a bearing and almost blocks it, or a broken bearing.
  10. If only fume extraction is important, you could look into soldering fume extraction systems? In the old days we had a sort of desktop bureau lamp with built-in fan and active carbon filter. No bigger than a normal desktop lamp. So you had a lot of light when soldering, and the fumes were taken away. But I don't know if active carbon filters out PLA and ABS fumes also. Just blowing them around, wouldn't improve safety... (My Ultimakers are in a chemical fume extraction cabinet in our lab, since I have it anyway. Doesn't seem to cause problems with the draft for printing PLA.)
  11. I found that stringing and "hairs" do mostly occur when: - printing rather hot, - printing fast (which requires printing hotter), - when increasing the flow rate and overextrusion happens, I noticed that strings occur when filament is leaking out of the nozzle opening. And hairs occur when molten residu is accumulated on the nozzle tip, and is sagging and touching the print. Or when the previous layers are overextruded or curled up, and the side of the hot nozzle touches these raised parts. Most materials string more when hotter. So, as yellowshark says, I would suggest you try printing
  12. I noticed that parts with big overhangs tend to curl up. The printer has to print part of those layers "in the air", so it has no good support. These overhanging edges can curl up quite a lot, even one or two millimeter. What may happen next, is that the print head brutally collides with these ridges, and knocks the print over. I have seen it happen in a testprint. Could this be the cause? If you have a compressor, you could try blowing cool air on the surface, to make it cool faster and get less curling up.
  13. It depends on whether your models are mainly geometric machine-like parts, or rather organic parts? To start with geometric models (machine parts), I would suggest you have a look at DesignSpark Mechanical, which is a limited version of SpaceClaim. Legally free. This is rather easy to learn, and you can find a lot of good tutorial videos online. For organic shapes, Blender is very powerfull freeware, but not that easy. Maybe you could also have a look at a modeler such as Form Z (www.formz.com), which is more geared towards architecture and product design? It is not free, but the price is s
  14. We don't have one, but I have seen one in use at a local distributor last year (I don't remember the brand). I found it rather disappointing: it couldn't scan inside an empty cup, under armpits, under a nose, under a car model, in an open mouth,... All these very common things left huge open gaps and/or defects. And then, once you had the scan, you could not really work on it, it was a huge mess of mesh. It only worked well for very simple objects, which you could as well design in 3D. So, whatever your scanner model of choice would be, I would suggest that you go to a local distributor, and
  15. Could this sort of problem be caused by long common ground wires, used for both power and sensing? Or something similar? So that some reference shifts up or down when a high power device (e.g. heat bed) is switched on and causes a voltage drop in these lines? I don't know the board schematics, so I am just guessing. Further, what part of the printer exactly causes the EMC-overshoot? Heated bed, wires, controller board,...? Could that be handled in a simple way by adding an (bigger) earth-line somewhere, or by shielding? In that case, might it be possible to officially say that: "On the condi
  16. When doing an atomic pull, if you have a thick blob in the area where the nozzle meets the teflon coupler, this means the teflon coupler is deformed: it has become wider at the bottom. I had the exact same thing after a few hundred hours of printing. If you do a normal atomic pull (=with pulling very hard) you risk dislocating the nozzle or teflon coupler, or even bending the rods. I would suggest you try a more gentle atomic pull, as described in my manual here: https://www.uantwerpen.be/nl/personeel/geert-keteleer/manuals/ This has far less risk of doing damage, because it is specificall
  17. After each print, when I am in the neighbourhood and I hear the printer finishing, I immediately clean the outside of the nozzle while still hot, by using a thick (!) tissue. Also when doing an atomic method, I often clean the outside too. I refer to this as "wiping its poop hole", to avoid confusion with cleaning the inside of the nozzle (atomic method). This also gives cleaner prints, since there is no brown residu sagging and leaking onto the next prints.
  18. Thanks for trying it with different materials and letting us know. I did not expect the salt method to work with other materials than PLA and PLA/PHA, so I am very interested in the results. Thus it seems to work a little bit, but not that well? On PLA indeed, when hot the bond is rock solid. When cold it pops off automatically. It has done so very consistently for over a year now, on about 1000 prints. Concerning the sugar method: for now I have no need to, but if I ever want to print in ABS, and if the salt method would fail (as I expect), I will for sure try the sugar method next, becaus
  19. Instead of using glue, you might try wiping the glass plate with salt water, prior to printing PLA. Gently keep wiping the plate with a moist tissue, until the water evaporates and leaves a thin mist of salt on the glass. This *greatly* improves bonding of PLA to heated glass. When hot (60°C), my prints bond rock-solid to the glass, I can't pull them off. But when cold after finishing, they come off without any force at all. But it does require a heated glass bed. For me, this works much better than printing on bare glass, or with glue. And you don't need to remove the glass from the printer a
  20. I would suggest you try wiping the glass plate with *salt water*, prior to printing PLA. Gently keep wiping with a moist tissue, until the water evaporates and leaves a thin mist of salt on the glass. This *greatly* improves bonding of PLA to heated glass. When the glass is hot (60°C), my prints bond rock-solid to it, I can't pull them off. But when cold after finishing, they come off without any force at all. So for me this is the perfect solution, much better than the "glue stick method" I tried before. And you don't need to remove the glass bed from the printer anymore. But it does require
  21. I suggest you try wiping the glass plate with salt water, prior to printing. Gently keep wiping with a moist tissue, until the water evaporates and leaves a thin mist of salt on the glass. This *greatly* improves bonding of PLA to heated glass. When hot (60°C), my prints bond rock-solid to the glass, I can't pull them off. But when cold after finishing, they come off without any force at all. So for me this is the perfect solution. But it does require a heated glass bed. Since I used this "salt method" one year ago, I printed about 1000 parts, often very complex, long and 100% filled parts, w
  22. After cleaning, thoroughly wash the glass several times with pure tap water only. No soap, no detergents, no cleaning aids anymore: they all reduce bonding. Then wipe the glass with very salt water. Yes, salt water. Keep wiping gently and let the water evaporate, until the salt dries into a very thin mist. To print, heat the glass plate to 60°C. This "salt method" gives a far better bonding of PLA to glass: when hot, it bonds rock solid. But when cold, the models fall off automatically, without any force at all. Since I started using this "salt method" one year ago, I have printed about 1000
  23. I think it might be two effects combined? - The 45° diagonal irregular extrusion might be a feeding problem (dirty nozzle, filament diameter variation, friction variations, worn teflon coupler, whatever...). - But the too thin areas parallel to the print head rather seem to be a glass problem to me. Glass plates are never perfectly parallel, they have variations in thickness. (Just like plastic or metal plates.) In a window this is often visible: you can notici it when the landscape behind gets deformed when looking through the glass. Or it could be warping of the glass due to heating? I hav
  24. Wow, that's a beautiful one. One tip: don't leave it in your car in the sun. I have had several PLA-models warping even in moderate weather (about 15°C, and a light sun with thin high clouds).
  25. Couldn't this be caused by underextrusion or irregular extrusion too? Possible causes of underextrusion that I experienced: - White teflon insulator on the nozzle is worn out and deformed internally, causing an irregular flow. (If this is the case, replace it.) - Dirt in the nozzle (if so, do an atomic pull). - Irregular filament diameter. - Filament is near the end of the spool, and/or wound too tight, so it acts like a tough spring resisting unwinding. I often manually unwind and straighten a few meters of filament, which greatly improves results. - Irregular friction between the filam
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