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geert_2

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Everything posted by geert_2

  1. Try to print with the nozzle temperature as cool as possible. And try putting a fan in front of the printer, to remove the heat as soon as possible. On very small items, I sometimes gently blow compressed air onto the print to cool it down faster. (Warning: only use compressed air from a compressor, never from a spray can: they may contain highly explosive gasses instead of air, and you don't want that on hot nozzles...). More cooling will not eliminate the effect, but it will reduce it.
  2. To test if it is the little fan: when the noise starts, just put your finger on the fan and stop it. It doesn't have enough power to cut off your finger. If it is the fan indeed, that noise indicates its bearing is getting worn out or running dry. This is a typical problem of cheap bearings, also in computer fans, model railroad trains, and model cars. Don't leave it screaming, because that further wears out the bearing, and it slows down the fan and reduces cooling. In the beginning, after warming up, the noise may go away, but that does not solve the problem, and it will gradually get wors
  3. In the beginning it really was a problem for me indeed: I often have difficult prints: long, 100% filled, with chamfers or roundings at the bottom, 5 to 15mm high. These excert a lot of warping force, even when using PLA. Printing on bare glass sometimes worked in cold dry weather, when it was freezing outside. But it never worked in rainy weather: then the filament would curl up immediately. I disliked the glue-stick methode: too messy, and bonding was still poor. And I could not use blue tape, since the underside of my models had to be totally flat. So I had to find something else... It to
  4. For a better adhesion to the glass plate, when printing with PLA, you might try my "salt method": - Clean the glass plate with handwarm pure tap water only, no soap. - Wipe the glass with a tissue moistened with very salt water, and gently keep wiping until it dries and leaves a thin, even mist of salt stuck to the glass. - Then print your model with the glass heated to 60°C. This gives a very good bonding when hot. For me this works much better than using the glue stick, or than printing on bare glass. I never use brims or rafts, even not for difficult models (except for inverted pyramids,
  5. I have my printers installed in a laboratory fume extraction cabinet (which I had anyway), so no need for this. But this thing looks a bit overkill to me, and it makes it a lot more difficult to reach the printer and to tune it while printing. If you only want to extract fumes, without enclosure, you might also consider trying solder fume extraction equipment. RS-components and Farnell should have them. Or maybe a simple kitchen fume extraction would also work? At least if you put another filter in it (maybe active carbon could work?).
  6. Maybe you can get it done with newer versions of Cura, but for older versions (I use 14.09), the following might be a work-around: if you designed these parts or you can open them in a 3D-editor, you could arrange them in the editor, and save that composition as a new design. Then Cura will consider this as one single model and print it. I am not sure why Cura draws the grey unusable area around models, also in all-at-once mode, but I guess it is to avoid the nozzle bumping into other model parts when moving from one part another, when combing is off.
  7. The biggest advantages of the "salt method" are: - It is a very comfortable, clean and fast method. - Since using this, I never had to take the build plate out of the printer. - And it sticks very well for PLA when hot (better than glue or bare glass). But it has no bonding at all when cold (less than bare glass). So I have no more worries about warping, and I never needed brims, rafts or whatever since using the salt method. I haven't tried any other filament than PLA, so if you try, please let us know. I am very interested in the results, negative or positive.
  8. Hello, And what is the result if you just manually extrude material? Thus "Move material" in an as smooth as possible way? This pattern sort of reminds me of LCD- or LED-display panels where a couple of X or Y datalines have bad contacts. Or an digital-analog converter where a dataline is broken. If you haven't done so, I would suggest checking all connections, all wires, for intermittent broken/bad connections. Especially those that are subject to movements (near the print head), and that are related to temperature and extrusion: temp sensor, heater, feeder motor. It could be broken solder
  9. Could that be a slicer problem too? Or wrong settings in Cura or whatever slicer you use? For example a check box that got (de)selected inadvertently? This weird but very regular pattern makes me think of those art lamps that do only print the 3D-mesh of a model (the "fish net"), but not the infill. Or a defect in the SD-card or card reader, where it only reads data partial, but skips other parts? (Try a different card, or remove it a few times to clean the contacts.) Has the exact same gcode-file worked well in the past, or did you slice and save the gcode again recently? If you manually
  10. If you correctly save your designs in the native DesignSpark Mechanical format (RSDOC-files), then there should be no reason why couldn't edit them afterwards. I have made hundreds of changes to my existing prototypes. So, could you verify that you save each design as an RSDOC-file first? If that is okay, but you still can't edit existing files, then the problem is probably somewhere else: wrong user rights on a file or directory? If so, try copying them to a FAT32-formatted device (USB-stick), and back, that removes all user-rights. I would suggest for each design and each version of a des
  11. 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
  12. 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
  13. 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
  14. 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
  15. 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
  16. 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
  17. That is really cool. I am actually surprised that it works without leaking everywhere between the seams, on this small scale. Geert
  18. - 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
  19. 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.
  20. 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.)
  21. 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
  22. 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.
  23. 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
  24. 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
  25. 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
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