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Everything posted by geert_2

  1. I do this manually, for example: "model_v1234_pet.gcode". But on my UM2 the name can be maximum 20 characters; the rest is cut off on the little display. So I often have to abbreviate the model name and version number. Depending on the priority, and if space allows it, sometimes I also include other specs such as layer height (if deviating from my normal 0.1mm), or the amount of models on the build-plate (if more than one). E.g.: "mod1234_02mm_3x_pet.gcode". This comes in handy after a couple of weeks, if I have to print the same model again.
  2. Does it have to be a circular tube? Or would a pentagon-shape also be okay? Or a triangle on top of a square, like a house-symbol? In that case, you could print it sideways, with the flat area towards the bottom, and the "roof" on top. I will try to insert a unicode symbol here, if the system allows it: ⌂
  3. Doesn't coldspray risk fracturing the glass due to thermal shock, or fracturing layer-bondings in the model?
  4. If you want dampers, I would recommend using professional and tested damper mats, of which the damping specs are listed. Each material has a resonance frequency, also dampers, in which they absorb less energy. A wrong "damper" could cause the opposite effect: the thing getting into resonance, like on a spring. So I wouldn't trust a spring-like design like that. Such damping mats should also be antislip, as gr5 says, so the printer can not vibrate off the table (we have seen a couple of these here on the forum...) In the early days of harddisks (late 1980's) I have seen
  5. For steep overhangs you need to use supports, or redesign the part so it has no steep overhangs. Or split it and glue both halves together, or print it in such a way that there are no overhangs while printing (if the design allows this; probably not here). I don't know your printer, so if it is a single nozzle printer, you would need supports in the same material as the print, and cut them out later. In dual nozzle printers, you can use one nozzle for the support material, and the other for the print, and dissolve the support later. You could design your own custom supp
  6. Does this effect also happen when you print a simple square tower, without any details, and without curves? In single-wall shels, and double wall shells? If yes, that would definitely rule-out model-geometry specific causes. I have no explanation for this effect, since normally PLA is supposed to print better when cool? At least in my experience... Or are there strong and variable air flows in the environment of your printer? Which would cause sudden temp changes of the nozzle? What if you put a desktop fan in front of the printer, to provide plenty of cooling air: does
  7. Okay guys, it's time to get your red/cyan 3D-glasses out! :-) I tried making a few anaglyphs (=red/cyan 3D-pictures) of a 3D-model. These 3D-images were hugely popular in the nineties, but I haven't seen much of them lately. They give a better understanding of the internal structures of a model, like watermarks; and give a better perspective and feel of depth. Also good for microscopy images of cells and fine structures, where the 3D-effect is important for understanding. They are reasonably easy to create in a 3D-editor: - In the 3D-editor, shift the model
  8. What if you print this in PLA? Does it come out right, or does it also have the same visual defect at the same height (although it might not break due to better bonding)? And what if you print this on its side? Does it then have a defect at the same height above the build plate (which could indicate a problem with the Z-axis), or does it have the same defect now running vertically (indicating a model defect)? When moved manually, does the build-plate or Z-axis move smoothly up and down, without hard, stuck points? Is the bottom of this model open, so you can
  9. On my UM2 I have succesfully printed PET, which I believe is a sort of co-polyester? Its brand was ICE from Trideus in Belgium. I had to download the file "materials.txt" from the UM2-printer to the SD card, and then make a new material-profile in that file, and upload it again to the UM. That profile lists the default temperature and material flow, and fan or no fan, and a chosen name. So I can now select PET from the printer-menu as material. Usually I print PET at 25...35mm/s, and 215...225°C, no fan, bed temp ca. 80...90°C, layer height depending on the model 0.1 or 0.2mm. For
  10. There are lots of different formulations, and lots of additives, so I think no one can give good general advice. You will need to look up the specs of each individual filament, or ask the manufacturers. Or do tests yourself: cut off a piece of both filaments and keep them in a flame. And see how it burns and how the fire propagates, or does it extinguish by itself? Also melt it with a very hot soldering iron, and see if it catches flame? Of course do this in a safe environment, e.g. outside, or in a kitchen in a metal sink, with plenty of water available. And with safety glasses.
  11. This sounds like general underextrusion, and may be not related to the type of filament (PCL). I think you would first need to sort this out with a well known standard filament like PLA, until that prints smooth. It could be a (partially) blocked nozzle, incorrect feeder tension, incorrectly mounted bowden tube, worn out teflon in the nozzle (not sure if this also applies to an UM S5?), too much friction somewhere in the feeding traject, etc... Search for "underextrusion". Personally I have no UM S5 and no experience with PCL, so it's hard to give more suggestions.
  12. The printer can bridge quite a lot, but then the first layer over the gap sags a bit. And I need to slide the other part of the keychain into that hole, so I want it to be more accurate. However, I don't want the supports to fuse with the underside of the model. So that is why I use these dimensions: they give reasonable accuracy and not too much fusion. But it differs from model to model, trial and error... So, I would suggest you try the concept on small test plates, to find out what works best for your materials, your printer (and printer settings), and your typical models. Also
  13. @gr5: thanks for clarifying the degree-thing: although I knew the setting, I didn't know what it refered to in the physical world. I took a look in DesignSpark Mechanical, and indeed, it defaults to 10°, and 0.5mm max deviation for STL-export, in "Fine quality" settings. See the picture below: the carabiner as designed, and as exported to STL (Fine quality, 10°, 0.5mm). For reference: the whole hook is 60mm long x 6mm high, and the text caps height of the watermark is 3.5mm, text legs are 0.5mm. The watermark is present but not visible in the STL-file: I made its color opaque to sh
  14. I just stumbled on a photo on my harddisk. This is why some supports have extensions beyond the area to support, so I can grab them and wiggle them loose. This makes support removal very easy. Otherwise it would be a nightmare with these small dimensions (see ruler in mm and cm). Also note the ugly defects in the Z-direction in the print: at that time I did not yet print these models with an extra dummy "cooling tower" to increase printing time per layer for better cooling. Sudden changes in total layer printing time, and thus differences in cooling, show up as ugly horizontal defe
  15. In the beginning when I started 3D-printing, my collegues of the department of Product Development suggested me to keep STL file-sizes below 20MB for normal models, even for their industrial polyjet printers. If you are in doubt which quality of STL export-settings to use, then cut out a small part of this design, export it with various STL-settings, and print these little test pieces next to each other. So you can compare and find the best balance between file-size and quality.
  16. Very hard to say from the photos, but at first glance it looks like the first layer is rather thick. So, could it be that the nozzle is a bit too far away from the build-plate? My first layers look way thinner, and they are usually defined as 0.2mm. PS: Beautiful letters by the way...
  17. I don't know the technical name for this in English. What I mean is that at the moment at which the outside of the heater reaches its temperature, inside there could already be so much more heat accumulated, that even when switched off, this heat when traveling towards the edge makes the temperature overshoot. This is also a common problem in heating systems in homes. If the heater shuts off at the desired temp of 20°C, then there might still be so much hot water in the pipes and radiator that it overshoots. Or the thermostat might be in a location too far away from the radiator, so it doesn't
  18. Maybe this? Weight of the (half-) full spool, minus the weight of an empty spool, and this sum divided by the weight of one meter of that same filament? You would need a balance and a ruler.
  19. I also think this is not the right direction for printing these models. Like in wooden matches: the grain of the wood should go in the same length direction as the match. Otherwise the match will snap if you try to light it. So this wing is likely going to be very brittle. It should be designed so that you can print all beams flat on the glass, and assemble these parts afterwards. So that it can absorb the forces and flex, like real wings. Meanwhile, for best strength, print rather hot and slow, but with fast travel speeds (so the nozzle doesn't leak while traveling thr
  20. Maybe the heater is too powerfull, or has a too big stored heat capacity, so it jumps over the set value? Or the sensor is too far away from the heater, so it senses the temperature changes way too late? Or the thermal connection between heater and sensor is not good enough (maybe try copper paste or the white paste like in CPU's for better contact)? Or something else along this line of thinking?
  21. Is the feeder *gear* not moving? Then this would indicate a slipping feeder wheel on its axis, maybe a screw that came loose in the feeder. Or is the gear moving but grinding the filament, and thus the *filament* not moving? Then I would suggest that you disconnect the bowden tube and manually insert a piece of filament and try to extrude manually. Directly into the nozzle. Clean the nozzle if necessary, and inspect the teflon coupler on deformation. Also, separately inspect every part in the whole feeding traject on too high friction: spool, feeder, bowden tube, nozzle. Also check
  22. How I came to the conclusions is simple: by printing thousands of models during the past 4 years, and by trying lots of different things. I wouldn't say I am an expert, but "advanced user" would be more appropriate. The experts are those who invented and developed the 3D-printers themself, and who worked with allmost all available technologies. Which I didn't. Note: you shouldn't just take my word on this topic, you should verify it by carefully testing. :-) But I do understand your concern. Working at a university myself, I know the rule: "A publication is only consid
  23. I won't have time to do tests, but from experience I can say a few things. For PLA, which is the most common material, bonding to the glass is affected a lot by moisture, when printing directly on bare glass plate without any bonding aids like glue. In a super-dry environment (e.g. freezing cold winter weather), bonding on clean bare glass is reasonably good. On very wet spring days, thus high humidity, bonding is very bad in my experience. Wiping the glass with *salt water* greatly improves bonding when printing on bare glass: it gives good bonding when hot, but no bonding at all
  24. Good that you found a solution. If the flowrate is too high, from observation, also check if the filament diameter is correct (both the settings and the actual diameter), before you change the hardware-settings. For example if the filament would be 3.0mm instead of the standard 2.85mm, or 2.0mm instead of 1.75mm.
  25. For my small models, and my single-nozzle printers (UM2), small ribs on top of the support worked best. Also, and very important, I always design enough features into the supports so that I can grab them carefully with pliers, pincettes, other tools, or I can get in there with a knife. And I split them in small chunks which I can wiggle loose easily. So, for these reasons, on delicate models I usually design custom supports into my models, instead of the automatic supports. See the red and orange supports in the first picture. The ribs on top are usually 0.5mm wide, and 1mm separat
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