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Everything posted by geert_2

  1. What happens if you print this model, together with a simple test tower next to it? Thus a different design that you make yourself, and put it on the same build-plate? Do they both go wrong?
  2. Indeed, if there is burnt residu in the nozzle, usually these flakes come loose when starting a new print, thus on the first layers only. I am not sure why that is, maybe because the cooling cycle between prints dislodges it? But I have often noticed that too. Sometimes I have to do 5 or 6 atomic pulls in a series before the dirt comes off (on my UM2, I don't have an UM3). Some materials work better for atomic pulls than others, for example Ultimaker Pearl PLA works well for me; it's a bit more sticky and glues better to the residu. Try whatever filament you have laying around. And
  3. The big pink/purple blob goes over *multiple* print lines, so it clearly is something that is dropped on the print from the *outside* of the nozzle. Problably some junk from a previous material that was still stuck on the outside. Might have been a bit stuck higher up, outside of direct view? Or some debris picked up by the nozzle while traveling around, then molten, and then deposited? Idem for the S-curved dark spot in the first pic. The tiny dark flakes along print lines, in the second pic, look more like burnt residu from the inside of the nozzle. This would probably require mu
  4. Inbetween the time you last used your printer and now, did you install anything else? Or did you have any weird occurrances? It looks like something corrupted your graphics drivers and/or your operating system? Maybe some graphics software that installed corrupt graphics- or .NET drivers? Malware infection? Severe software crash with harddisk corruption? An automatic Windows update gone wrong completely, or interrupted? Or something else along that line? If *none* of your graphics software works anymore, it is on a system level, not application level.
  5. Thanks. These are very interesting data, and a very good starting point for selecting materials. Maybe this thread should be sticky? Actually, I am a bit surprised at the positions of Taulman 618 nylon , and colorFabb XT and HT. A suggestion: as you accumulate data, maybe you could add a sort of "error bars" to the values in the second graph (with green, yellow, and orange ovals)? Both horizontal and vertical lines. These error bars would indicate the useful range. Then for example PLA might sit at 210°C, but its error bar might go from 190 to 220°C. While another mater
  6. I don't think this is going to work. The main problem is that most 3D-printers do cause hairs or strings, when jumping from one spot to another, especially for when printing very small pillars. And in this design they have to jump a lot. So you are going to have lots of short-circuits. If you would print thin full layers on top of each other (thus: layer1=pos, layer2=insulator, layer3=neg, layer4=insulator, layer5=pos, etc.) you might have more success, but still. When printing, the nozzle often gets dirty, and drags around material which is deposited somewhere else. This too could
  7. What is the technical relation between speed and this bumpiness? I guess it has to do with higher pressure in the nozzle, but I don't see how a higher pressure would cause these irregularities? I would expect them near corners, where the head has to slow down, but not halfway a smooth curve? And if they would occur, why not on every layer, but seemingly random? There must be a valid technical reason, because the facts are what they are, but I just don't see it...
  8. If you print a couple of these horseshoe clips, next time it becomes a lot easier to remove them and insert them. The basic dimensions are the same as the standard clips. I have been using these for 2 years without issues. For the design files, see my page (near the bottom): https://www.uantwerpen.be/nl/personeel/geert-keteleer/manuals/
  9. Or you could design the supports manually, as part of the model. Then you can use lines, ribs, thin walls, columns, blocks, or whatever shape you want as support. This gives you more control. And you can provide features to make removal easier, such as protrusions, or holes where you can insert tools. For example:
  10. I think it is very unlikely that you run out of filament unexpectedly, since before the start of a print you can see how full the spool still is. After a couple of prints, you know how much your models will consume. The risks are rather: a blocked nozzle, filament grinding due to too much retractions, a kink in the filament that can't get through the feeder (I had this once), flexible filament getting stuck in the bowden tube, or something similar. None of these are "end of filament" conditions, so none would be detected by a simple mechanical switch. You would need something that detects moti
  11. Another solution is to make the design in metric dimensions from the start. In the future, engineering in the USA and UK will switch to the international metric system anyway. They are about the only countries that are still behind. So if you do the switch now, you will have a very gradual and smooth transition, and you will be used to it by the time it becomes compulsary. Once you are familiar with the metric system, you won't regret it, because it is so much easier to do conversions. No more horrible multipliers to go from inch to feet to yard to miles to nautical miles... Just move the deci
  12. I do not have an UM3. But a knocking sound seems like some play somewhere in the system. For example screws of the stepper motor coming loose, or something similar. Or something loose in the nozzle. Have you tried removing the bowden tube, but leave a little piece of filament in the feeder? And then manually move that piece of filament up and down? Next, idem for the nozzle: manually dial up temperature, manually feed a bit of filament, and manually retract it? Then Maybe you could feel where the problem is?
  13. Wow. From the photo I can't tell if this is a 3D-print or a real bronze model.
  14. Depending on the situation, another good option to minimise these lines, might be postprocessing and chemical smoothing. See the thread on "Acetone smoothing" by user Cloakfiend who has done the most experimenting on this, and who achieves excellent results routinely. His models have virtually no visible lines. It's a lot of reading, but then you get a wealth of info too.
  15. First make sure that the bed is leveled correctly and is very clean (clean it with pure water, no soap, no detergents, since soap reduces bonding). Then you could try this: wipe the glass plate with a tissue moistened with salt water. Keep wiping gently while it dries. This improves bonding, but only works for PLA. For the full manual, see: https://www.uantwerpen.be/nl/personeel/geert-keteleer/manuals/ For other materials than PLA, you might need to use glue (10% while wood glue dilluted in water, user gr5's method), or hairspray (user neotko's method).
  16. I don't know Green-Tec, so I can't comment on that. But have you tried to remove the bowden tube at the nozzle, and then feed the filament manually, while adjusting the temp in steps of 5°C? This might give you a better feel of how it behaves, and at which point it starts to flow well. Of course, a few atomic pulls might also help. It could be that the nozzle isn't blocked, but the opening is a bit reduced, or that the internal walls are covered by burned residu, which hinders heat transfer? You could try my more gently atomic pull method: remove bowden tube, manually h
  17. When it is worn out. That depends on the temperatures at which you print. Once above 210...220°C, the old teflon couplers degrade quite fast, especially when printing fast (=high internal pressure). When printing slow (=low internal pressure on the molten filament) and cool (=less thermal deformation and break down), then it lasts much longer. I usually need to replace them every 200 to 300 hours on my UM2 (non-plus), when mostly printing PLA at 210°C, and PET at 220°C. Apart from that I haven't replaced anything yet, and both printers have about 1000 hours. Although I made a few minor modific
  18. If the hole is only 3 to 4mm diameter, you usually do not need supports for most materials. If the design alows it, you could taper the holes near the end (like in blind holes drilled), to improve the inner shape, if that would be required. For a bit larger holes, let's say 10...15mm, I design custom supports that are strong enough to wiggle loose and to pull out, and that have enough clearance to insert tools next to it, or that have holes where I can insert hooks to pull, or something similar; it depends on the design.
  19. If you are familiar with SketchUp, then another free editor you might want to try is DesignSpark Mechanical. It only requires registration, which is a fair price. It is a limited version of the commercial Spaceclaim. The user-interface is very similar to SketchUp, and there do exist lots of good training videos. (And you can also use Spaceclaim's, if you keep in mind the limitations.) I have made hundreds of models, and *never* had any problems with the STL-files.
  20. I think for 3D-printing it might be possible to reduce file size to a few 100MB, and still have good quality, as very fine details are lost anyway in a 3D-print?
  21. Indeed, concerning "base" I meant something like a brim. Or a custom made brim-like plate, maybe with a few custom made tree-like support columns to support the overhanging middle parts, if you print it in one piece. If you print it in two pieces, cut halfway, this might not be necessary.
  22. That is a really nice model. Where did you get that? An alternative to printing the globe at once, with supports, might be to split the model along the equator, print both halves separately, and glue them together? But then you will need to post-process the seams. For good stability, I would make the shell thick enough, maybe 1.2mm?
  23. What I would do in that case is: - First do a couple of "atomic pulls" to clean het nozzle. Then you are sure there is nothing blocking the nozzle, and the inside of the nozzle is not totally covered in ashes which might hinder heat transfer to the filament. Also, by the shape of the molten part, you can also see if your teflon coupler is worn out: this will cause a sort of blob or lip deformation in the molten and cooled filament, near the edge between the brass and teflon part. - If this blob or lip is present in the pulled out filament during atomic pulls, you defini
  24. Cura can not directly open 3d-design files. You need to export your design from your 3d-editor to the STL-fileformat. And then open that STL-file in Cura, or in any other slicer of your choice. And then save the result as a gcode-file for the 3d-printer. For exporting to STL, usually a few standard quality settings will be available, depending on the editor (I don't know Cadkey). Try medium quality for big objects with not too much details, or fine for objects with much detail. Of something equivalent. This is trial and error to see what works best for your typical desi
  25. Most of the time I make a gap between parts of 0.1mm for a tight fit (requiring force to insert), and 0.2mm for a normal or loose fit. This is usually sufficient for the normal irregularities due to layers, rounded edges, ringing effects, occasional small blobs, slowing down on corners, etc... For small gaps, I take larger tolerances, based on experience, or after trial and error. For example, a 4 mm hole usually ends up as a 3.5mm hole. Then the best solution is to go through it with a 4.0 mm drill (manually!!! Never electrically, this melts PLA). Rounding bottom edges with a 0.5mm round, red
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