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geert_2

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Everything posted by geert_2

  1. Glad you found a solution. I like the idea of printing topographical maps. Where did you find good quality images? Another question: do I understand it correctly that the main purpose of this procedure is to round the 4 corners of the image (but not the mountains themself)? Like a plastic bank card? And to "drill" a hole in it? If so, couldn't the same be achieved in Photoshop by changing the black and white levels of the image, and adding a black or white border around it? (Depending on whether black or white is zero height?) And then import it in Cura and set the base to zero, so that this black border is not printed? Then you could do everything in a graphic editor, and just export a JPG-file. Maybe this might add more flexibility, and you could more easily add logos and stuff? I did a quick concept-test, and with a bit of trial and error this seems to work in an older Cura version, but I don't know in the newest. Edited in Photoshop from a (too) low-resolution image. I set the base thickness to zero, so the black border would not be printed, and the dark grey Rhone-valley is now the lowest part that would be printed. Edit: cutting off 0.1mm from the bottom improves the view in (my version of) Cura.
  2. As far as I understood, slicers don't do boolean math on the STL-files. They rather "count walls", sort of. The first wall it encounters, it switches material on. The second wall = material off. Third wall = material on, fourth wall = off, etc... So any objects totally enclosed by another, will automatically be subtracted and become hollow upon slicing and printing. (But correct me if I am wrong on this.) At least, this is how I make hollow watermarks. In the beginning, I made complex subtract-operations in DesignSpark Mechanical on my CAD models, to get these hollows. But this made subsequent editing difficult, because these hollows are hard to reach. Now I don't: I just move the watermark logo and text inside the main model, without subtracting. So they are "solid blocks inside of other solid blocks". Upon exporting to STL, it makes triangles of those watermark-surfaces. An STL-file just consists of surface-triangles, as far as I understood. No colors, no materials, no solid/hollow-definitions, no dimensions; just triangles... And these triangles are then automatically sliced and printed correctly, using the "wall-count" method. Not sure how it would/should handle models that partially overlap each other, if it should do the exact same, or throw an error? A few examples of watermarks done in this way. Most of the watermark text is 3.5mm high, character-legs are 0.5mm wide, and they are sitting 0.5...1mm below the surface. Obviously, this requires transparent or translucid filament.
  3. The old Cura versions (14.xx) did something like this: it started at the shortest distance away from the current nozzle position, to minimise travel. However, this causes weird infill behaviour in that it starts filling halfway a surface, for example it starts at infill-line nr. 50 and fills-in to line 100, and then jumps back to line 50 and fills up to line nr. 0. This causes weird travel lines in the infill. And in the end it causes more travel instead of less, because of all the required jumps halfway the infill. Instead of nicely filling from line 0 to 100. Maybe you can also reduce problems by setting a high travel speed (to minimise the interruption time), printing slow (=less flow and less pressure buildup in the nozzle), and printing cool (=less leaking, and less heat traveling back up in the filament)? Also, some people slightly oil the filament, to make it slide better through the bowden tube. Some had printed a little-sponge container for oiling and dust-filtering the filament. There have been posts and photos about this subject on this forum, maybe you can find them? If your models would use 100% infill, you could also set wall thickness very high, so it only prints concentric lines, instead of diagonal infill. This causes less traveling at the outside of the model, but it still causes some jumps in the core. Preview the effects of your settings in Layer-View.
  4. Probably not the answer you are looking for, but what about making a human part of the art installation? And let him/her do that? Put him/her on a marble base plate, attach a nice brass label similar to those on stone statues, and shine a spotlight on him/her? That "human piece of art" can handle things like parts stuck to the build plate, or parts falling off prematurely, or cleaning a blocked nozzle. An automaton can't, or not that easy. Further, a human seems way more artfull to me than a silly automaton, and probably way more beautiful too (depending on who you choose, how he/she behaves, and how you clothe him/her). I think humans are masterpieces of art, well, at least some of them.
  5. Maybe you could try cutting out critical parts or features from the design, and assemble them in a small test piece? Then try printing this until you get it optimised.
  6. If this teflon coupler was on my UM2, I would replace it, if I had printing problems. There seems to be an indent inside the tube, close to the bottom, and the inner diameter seems to have gotten oval instead of round? But this is hard to see for sure on photo, as there could be weird light-effects too. Concerning bonding, I think gr5's method with dilluted white wood glue should also work well. At least it did work well when I tried it for PET some years ago. But my "salt method" will *not* work for ABS.
  7. In addition to the heat-problem described by |Robert|: The resin will most likely glue firmly to the PLA. You would need a very good release coating to prevent that. Test the compatibility of the release sprays or coating with the resin: if incompatible, it might prevent curing, and you would end up with a sticky mess. Release-sprays might make painting difficult; you would need to degrease thoroughly. Concerning heat: in the old days, when mixing epoxy resin in plastic cups, or even in metal (lead) cups, I often saw these melt due to the heat in the left-over resin. So you would need a slow-curing or low-exotherm resin. If you keep these things in mind, I think it is worth trying. Another option would be to make a silicone mould from a 3D-printed part, and use that silicone as base for applying the carbon fiber and resin. Silicone can withstand much higher temps, and it is by itself non-stick. But even then, thoroughly applying release spray greatly increases mould-life. Silicone is porous for oils, solvents and resin-vapours: so they would soak in, and over time cure in there and destroy the silicone's flexibility.
  8. And try all these things on a *small* test piece first, so you don't waste too much time and material. First inspect in Cura layer-view if the infill pattern does what you want, less or more, and only then print a small test piece. Maybe another option might be: 3D-print a *heavy solid* mould, ply anti-insect mesh over it, and use that mesh as mould for your paper? If you use stable steel or brass mesh, it might be strong enough? Or something else along this line of thinking? You might be able to use gypsym bandage too, like the ones used in hospital for broken legs? Then you could use the 3D-print as mould for the gypsum. Gypsum is porous and can let some air and water through, but maybe not enough for your application? Edit: the advantage of gypsum and metal mesh is that you can heat them, e.g. with a heat gun, to speed up drying. You can't do that with plastic moulds.
  9. I don't have much experience with it, but ABS is said to decompose fast in the nozzle, if sitting there for too long (=or too hot, or printing too slow), causing clogs. If that is not the case for you, then have you checked that the little fan for cooling the nozzle is working well? On an UM2 this is sitting behind the nozzle, invisible from the front. I don't know where it is on an UMO. This could suck-in hairs and debris, and get stuck. Also on an UM2, a severely worn out white teflon coupler could cause underextrusion after a while. I don't know if an UMO has something similar? The white filament-end after a cold pull on an UM2 shows a thickening where the teflon coupler is worn out. But I have seen even worse. This hinders the material flow. Not sure if any of these could be the cause for you, but it might be worth checking?
  10. Ah, okay, I missed that "straight through" part. I don't dry PLA and PET. Although I do store them in a box with dessiccant. But while printing I just leave them in the printer, sometimes for several days or even weeks. Doesn't seem to make much difference. PET seems to be a bit water-repellent. And PLA seems to get a little bit duller over a couple of years time due to degradation, but I am not sure if that is mainly UV-light, or due to moisture, but it is going *very* slowly over years, not days or weeks. If I would use nylon or ABS, I would dry them though.
  11. I made a tool to scrape off this primer. It is plied from very tough steel spring (same as used in dental appliances for kids, 1mm thick), so it clamps very well and does not come loose. It hits the nozzle, bends downwards (it's a spring), and scrapes off the blob. Works very well 99% of the time on both of my UM2.
  12. Does it crack along the layer lines, or does it completely ignore layers and go diagonally through them? My experience with PET is that it is less strong than PLA, it will break sooner under high loads, but it can flex more. It will fracture without warning, all of a sudden. Fractures ignore layer lines (indicating good bonding). Also, it has less creep due to permanent loads than PLA. So for keychain mechanisms, carabiner hooks, and snap-fit locks it is better than PLA, since they need to flex to function. However, the PET keychain will break much sooner when it gets stuck in your pocket when you sit down. So it is far less forgiving than what you would expect, based on experience with cola/water PET drink bottles. I print PET without fan, but at low speed and very low temp: the absolute recommended minimum, or even less: 210...215°C (recommended: 215...250), for 0.1mm layers, and 25...35mm/s. A higher temp did not improve quality nor strength: it caused bubbles and more stringing. The downside of no-fan is that overhangs and bridges are terrible, but for my long and flat models this usually is no problem. Using fans decreased layer bonding, and caused a tendency to warp in long flat models. (I print on bare glass, wiped with a tissue moistened with salt water.) Printing extremely slow (10mm/s) causes the material to get brown, thus indicating beginning decomposition in the nozzle, but it gives excellent bonding (plenty of time). So I do think that some decomposition occurs, and that the indents caused by extruded sausages may concentrate stress and initiate cracks, and make it fail much sooner than injection moulded parts. Not sure about crystalisation: I don't see it getting opaque. But I am no chemist, so maybe I can't recognise it. Anyway, try various settings on small test pieces, before doing large models. That is why I do the keychains, and I use them every day in my pockets. :-) See my comments and photos in this thread: https://community.ultimaker.com/topic/30778-printing-airtight-with-petg/?tab=comments#comment-254606
  13. The fact that 3D-printing produces smell, means that it produces gasses and/or particles. Composition and long-term effects might not be totally known, in new and rarely used technologies (=rarely used compared to the number of people in general). So I think it would be best to provide some sort of fume extraction anyway, even with the cleaner printing products like PLA and PET/polyesters. Maybe similar to the one in a kitchen? Or a simple pipe with fan that you place close above the printer? If you can not get the exhaust pipe to the outside, you could use a system with active carbon filter. Google for ideas and options. My printers are sitting in a fume extraction cabinet in my laboratory. This is an expensive thing (5000 euro?) and way overkill, but I had it anyway and didn't use it much, so.
  14. That exFAT is probably going to be the problem? I would suggest you buy a couple of thumbnail 8GB or 16GB sticks, and just leave them with the printer. I guess USB2 would be preferable over USB3? Theoretically it should make no difference, since USB3 is downward compatible, but you never know? And speed is obviously of no concern here. :-) They cost less than 10 euro/piece these days. A tiny little thumbnail stick doesn't stick out too far, so less risk of hitting and damaging it. Make sure they are FAT32. I once tried reformatting a 64GB exFAT stick into FAT32 (for another purpose, not for 3D-printing), but that didn't work well. Had to reformat it back to exFAT.
  15. I never tried it, but I would think the "dot-method" would also work with stacking, on the condition that you merge your model-stack in CAD. And export the whole combination as one STL-file. But obviously you are going to need a lot of support material if the models would be irregular, and I think the risks of something going wrong could increase as you get higher in a stack, e.g. support and model not bonding well, or underextrusion, or running out of filament... So while I do understand the desire to print as much as possible in one batch, especially if you are on tight deadlines or have a high volume to print, it is not something that I would like to do for myself. But it might work well for flat models like coins, or walls of architectural models. So this would be the concept, in perspective and side view (just a quick and dirty sketch, don't mind the non-optimal positioning):
  16. I have two UM2 (non-plus, thus the version before the UM2+) printers and they are still fine for what I need them for, mostly long flat models that need no support. So if you only need one color and no dissolvable support, it should be okay. But I would suggest that you make a testprint first, to see if everything still works fine, and the printer isn't abused or damaged (e.g. by dropping, printing abrasive materials, things burned out, damaging mods,...). This is usually repairable, but then the costs might no longer make it the best choice.
  17. No, I didn't change the flowrate, so it was the standard for PET on my UM2, and I left it at 100% on the machine. I had to look up temperatures for these test blocks (I had written it down somewhere): - all were 215°C, except: - 0.06mm layers at 10mm/s (unpolished block) = 210°C - 0.06mm layers at 10mm/s (polished block) = 200°C - 0.4mm and 0.3mm layers at 50mm/s = 225°C due to the much higher extruded volume The recommended temp range by the manufacturer is: 215...250°C, so I am at the lower edge. I once tried higher temps too, but that gave more bubbles and more stringing, and faster decomposing and browning. By the way: test blocks are 10mm x 20mm x 10mm, and watermarktext is 3.5mm caps height. I don't really know about part-strength vs. layer-height. But from these tests it was clear that thicker layers and faster speeds gave more "frosted glass effect". That means more voids, and probably less strength (but I am guessing now). Printing at 0.4mm layer height was still possible, but then cooling became an issue: the block didn't cool down fast enough and it started deforming. I would suggest you run a similar test, but maybe with a testmodel more suited for your application and more similar to your final models (e.g. with overhangs and bridges if you need these). This gives good understanding of your printer and your filament, and you will win back that time investment very fast.
  18. On my UM2 (=single nozzle) I get watertight PET parts by printing at low speed, low temp, thin layers, no fan. Usually 25...30mm/s, 215°C, 0.1mm layers, bed 80...90°C, 0.4mm nozzle. But 0.06mm layers are even better. At slow speed, print cool to prevent the PET from decomposing and getting brown. Layer bonding is excellent: when overloaded, fractures run diagonally through parts, disregarding layers. Main disadvantage of no fan, is that overhangs and bridges are terrible since the material won't bridge well. But for my long flat models, this usually is no problem. If you would use PVA-supports on an UM3, any PVA strings might cause holes in the PET. Consider using PET for supports (thus a single material). Print a few small test parts before doing a large real part. Pictures: Test blocks in PET, layer height from left to rigth: 0.4mm, 0.3mm, 0.2mm, 0.1mm, 0.06mm. Top row printed at 50mm/s, bottom row at 10mm/s. All 0.4mm nozzle. Slowest and thinnest-printed test blocks are getting brown due to slow material flow in nozzle. Testblock at 10mm/s and 0.06mm layers, left as printed, right polished. Transparency indicates good layer bonding and very few internal voids. Absolutely watertight. The 3D model. Text is a hollow watermark, sitting halfway in the testblock. Keychains in PET. Ruler units are in mm and cm. Fractured carabiner hook: fracture pattern radiates in all directions, mostly not following layer lines, indicating good layer-bonding. Idem, other side. ----- end -----
  19. Ik denk dat niemand nog een raft gebruikt. Maar waarom zou je niet gelijk op de glasplaat printen, dat werkt prima? Als je perse een soort raft-achtig ding wil, kan je misschien een dunne plaat ontwerpen in CAD, en die printen met beperkte infill (ca. 50%? - Probeer op kleine teststukjes), en zonder top layers?
  20. Maybe move your bed closer to the nozzle, or make your first layer thinner, 0.1 or 0.2mm? I get really glossy bottom layers with both PET and PLA. Print on a glass bed, not on tape or some other rough surface. Hard to see in the photos below, because the reflection is out of focus, but these bottom surfaces are high-gloss and do reflect like shiny injection moulded parts. The "copyright design ..." watermark text is hollow and sitting 0.5mm below this glossy bottom surface. For reference: text caps height is 3.5mm, character legs are 0.5mm wide. High-gloss bottom surface of keychains. The ruler is in mm and cm.
  21. I don't know your printer, so this is guessing. To me this looks like a hardware issue. Maybe some connectors that are not seated well or are oxidated? Or electromagnetic noise on the power line or environment? Motors starting or stopping causing pulses, or sparks you get in cold dry winter weather? Or a cell phone going off nearby? This sort of things can easily lock up electronics. (Cell phone often locks up my USB-keyboard and mouse.)
  22. If you want to examine a 3D-print in detail, but you don't have a microscope or good macro lens. Try using your webcam or smartphone, and add a close-up lens in front of it. Then watch the picture in full size on your computer screen. You could use any old camera lens as close-up lens, provided that it is concave and does not cause too much distortion. Or buy a dedicated smartphone adapter with close-up lens. Magnification will differ depending on its focal length. If required, design and 3D-print a lens holder for mounting the lens onto your camera. The results are not perfect, but not too bad either. Sharpness is okay. There is considerable cushion distortion, but that is not too important for this kind of pictures. The photos below are from a Logitech C525 webcam, and an old ocular camera lens as close-up lens. But the concept should work with any similar webcam or phonecam. Test photos: 3D-printed keychain with watermark text inside. Text caps height is 3.5mm, leg width is 0.5mm, and text is sitting 0.5mm below the surface. Material is transparent PET. Underextrusion test. This is at 50% flow rate. PLA. Insect antennas on a print, after I forgot to enable retraction. A standard Bic ballpoint tip. Micro-electronics from an old video camera (good for recovering lenses too). The resistors (little black things with numbers) are ca. 0.6mm wide x 1.7mm long. Fingerprints. Flintstone-text: here caps height is 3.0mm, leg width is 0.42mm (in the design, probably more in print), printed on an UM2 with 0.4mm nozzle, 0.1mm layers, 25mm/s, 200°C, PLA. The equipment: Logitech C525 webcam, with an old camera ocular lens attached. Obviously, I still have to design and print a decent lens holder... But any similar equipment with small cam and lens should work. Test subjects, with ruler in mm and cm for reference. ----- end -----
  23. I don't know your printer, so just guessing... Maybe a blocked nozzle, and then the filament cooked, burned, and spilled all over, due to sitting too long in the hot nozzle? Or something along that line, where the filament got stuck? Some materials burn away rather cleanly or leave black coal dust (like the PLA that I have), but some burn into a sort of glossy varnish that is hard to remove (like the PET that I have).
  24. In the beginning I also had this problem. But now it is extremely rare, even though I have lots of models with small openings. Maybe you can solve it by adjusting nozzle height a bit closer, or changing temp or speed of the first layer? Or improving your bonding method? Also, a thinner first layer gives better bonding and less risk of the first outline being ripped off, on my printers. A 0.2mm layer sticks *much* better than a 0.3mm for PET and PLA: this is just my observation, but I am not sure why.
  25. The whole world has switched to the metric system officially, so I think we should stay with the metric system. And not go back to medieval units that don't work well in high-tech environments, no matter how much sentiment there is in it. I grew up with "horsepower" for car engines, which now has changed to kilowatt. I regret this, because the horsepower-number is higher and thus more impressive than kW, and because I grew up with it, but kW makes calculations sooooo much easier. No more weird random conversion factors. The USA has switched to metric in 1875 (yes, 18...), although some politicians and press are still not aware of this, and the UK has switched more recently. Asia is metric since long (except a few former British colonies), and it is quickly becoming the dominant world power. As soon as they have enough power, I am very sure they will enforce the metric system even in the aviation industry, the only industry that currently is still partially imperial (and then even with a bizarre mix of British and US units, and metric, causing confusion and accidents: some time ago a plane ran out of fuel and crashed, killing all souls on board, after confusing metric and imperial fuel units when refueling). If we don't want to be left behind, I think going fully metric is the only option, even though it might hurt our sentiments.
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