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Everything posted by geert_2

  1. Yes, that could work. But it could also fuse the support into the model, making it very hard to remove the support without extensive cutting and damaging the model. You have to test this first on a small test-model with variations. If I would have dual nozzle machines, I would use PVA-support in this case. However, to minimise PVA consumption and to maximise stability, I might custom design most of the supports to be printed in PLA, and only do a small PVA interface in-between. And I would use a sort of dovetail to make the PVA- and PLA-supports grip well onto each other. I can't t
  2. As gr5 already mentioned: don't use ordinary PLA: it may work a couple of times, but after a while it gets harder and tends to break. Even when printed in the "right direction". And it has too much permanent creep-deformation under continuous load. I use PET now for snap-fit lockings and keychains. It has enough flexibility to survive, and is still easy enough to print. Haven't tried tough-PLA yet, it's on my to-do list. And indeed, do small test pieces first, until you get them right. I would also recommend that you make keychains, carabiner hooks, cloth hangers, and s
  3. Most consumer electronic components are designed for a long-term maximum operating temperature that you can still touch, although barely, about 60°C. This is heat due to power dissipation in an environment of 25°C. Especially electrolytic capacitors, diodes, small transistors, chips, LEDs,... are sensitive. Power transistors and -amplifiers, and resistors, can usually withstand a lot more. Above that temperature the components usually don't die immediately, but their life shortens a lot. And power drivers need to be able to release their heat. I don't know about Ultimaker electronics, but I do
  4. 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
  5. 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 mad
  6. 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 r
  7. 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 c
  8. 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.
  9. 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.
  10. 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
  11. 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 hosp
  12. 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 somethi
  13. 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 thoug
  14. 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.
  15. 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
  16. 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 car
  17. 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
  18. 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 h
  19. 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.
  20. 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 bu
  21. 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.
  22. 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?
  23. 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-g
  24. 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.)
  25. 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
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