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Everything posted by geert_2

  1. Bill2 and peggyb: thanks for the info! Geert
  2. I use DesignSpark Mechanical, distributed by RS Components. This is a free but limited version of SpaceClaim. Pro: very handy user interface: can work by pushing-pulling features or by entering dimensions numerically. Easy to learn. Lots of good training videos available (you can also use SpaceClaim's videos, if you take into account the limited features of DesignSpark Mechanical). Ideal for designing mechanical and machine parts. And for parts that you want to keep editing afterwards. Thus ideal for let's say designing parts for a 3D-printer, feeders, etc... Contra: STEP- and IGES-file impo
  3. That machinable wax, is that available in 2.85mm filament? Or do you use some feeder/melting pot you designed by yourself on top of the printer head? If filament, how wel does it transport through the bowden tube and feeder? Thus without breaking, and without grinding? Such wax might also be very usefull for artists who want to make bronze sculptures in the traditional way by moulding and casting. Instead of making a clay original, they could print it in wax. Or for casting small automotive parts in iron or aluminum, such as model airplane engine parts.
  4. For your next prints, I would suggest that you give the "salt method" a try. (=Wiping the glass plate with very salt water, prior to printing. No glue, no hairsprays.) For PLA this gives a very strong bond when the glass is hot, but no bonding at all after cooling down to room temp: the models just pop off. No more need to take the glass out of the printer, no more recalibrating the build plate... I use this since more than a year, and have had no problems since: no bonding problems, and no removing problems. For the full description, see the PDF-manual at: https://www.uantwerpen.be/nl/per
  5. Since more than a year I haven't levelled the bed on both my UM2 printers. No need to. Using the "salt method" to glue PLA to the print bed, my models stick like rock solid when hot, and pop off by themselves when cold. So I never have problems removing the models from the plate, I never need force, and never need to take the build plate out of the printer. So, for me autoleveling would be useless. (Although I can understand that people who daily change nozzles and materials might see things differently, especially if the nozzles are of different length.) Instead of autoleveling, I would ra
  6. If you created the model or you can edit it, you could try designing the supports yourself. For very fine details, you might want the supports to sit closer to the model for higher accuracy (e.g. a gap of 0.2mm). And for larger parts the support could be further away, for easier removal (e.g. a gap of 0.4mm) but then with less quality. Also, I often design features into the supports to make removal easier, for example: extensions on which I can get a good grip with tools, or spaces where I can access some areas easier with a knife. Or holes to put in a hook and pull the support out. It takes
  7. Wow, that is really amazing detail. Do the parts move correctly too?
  8. This is how the bowden tube should sit in the teflon coupler, and how I would suggest that you cut off the tip of filament for easier inserting.
  9. Hi nallath, Can old and new (>2.1) Cura versions be installed parallel on the same system, without messing each other's settings up? Do they use separate directories and files? If so, people could simply install both, and use the version that works best for a particular task. Or they could just keep the old one as a fall-back. Geert
  10. Have you tried the "salt method"? See here for the manual (PDF-file): https://www.uantwerpen.be/nl/personeel/geert-keteleer/manuals/ Let us know if it works.
  11. Oils do reduce bonding, and wax being oily by nature... Probably you need more mechanical grip? Maybe blue painter's tape might work? Or any other rough sheets? (Has anyone ever tried a sheet of sandpaper?) Or maybe you could melt a thin layer of wax or parafine/stearine all over the build plate, and let that cool? I have no idea if it would work, but the parafine/stearine from candles is sometimes very difficult to remove from glass. So it could work? Tea lights usually consist of parafine, very thin birthday candles consist of stearine, and normal candles are a parafine/stearine mix. Stear
  12. You could compare it to material fatigue cracks in plastic parts: they too do usually occur in the same region: where the load stress is highest, or where there is a weak point in the model. So you would see fatigue cracks around screw threads, around inserts, at sharp corners, at attachment clips, around changes in part thickness, in thick solid blocks with uneven cooling and high shrinking, etc. I am not saying this is the case here, I don't know, but it seems one of the possibilities. So if there would be poor layer adhesion, due to whatever reason (too low temp, wrong cooling, underextrus
  13. When looking at the photos, to me it seems that the models do only crack after the printing, or later on, but not immediately: some of the broken layers are partially stuck to the upper part, and partially to the lower part. And the cracks are in a similar region, but not at the same layers. So I would guess this is caused by poor layer adhesion and shrinking, rather than by Z-movement problems? Could it be underextrusion due to printing too cold? Or a worn out teflon coupler? Or partially blocked nozzle? Or filament problems (to thick, variations in diameter, near the end of the spool and
  14. geert_2

    Warping bei PLA

    The ratio does not really matter, and I have never exactly measured it. I just mix it so it is "quite salt", but not so much that the salt does not dissolve anymore. The water evaporates anyway when applying it to the glass. More important is that you gently wipe the moistened tissue over the glass plate, and very gently keep wiping while it is drying, so you get a very fine, thin, even mist of salt stuck to the plate. Almost invisible. This seems to work best. (There are a few photos in the manual that show it.) For me the biggest advantages of this method are: - excellent bonding when the
  15. geert_2

    Warping bei PLA

    Hello, I can understand and read a bit of German (Deutsch), but can not write it. If you can read English, you can find the manual on the "Salt method" here: https://www.uantwerpen.be/nl/personeel/geert-keteleer/manuals/ Basically, it consists of gently wiping the glass plate with a tissue moistened with very salt water, prior to printing, and let that dry into an even, very thin mist of salt. Then print PLA with the glass plate at 60°C. This gives a very strong bonding while hot. At the end, when the glass cools down to 25°C, the models just pop off, there is no bonding at all. Since I
  16. If it might be printed in a plate of let's say 1cm x 1cm, and used as a sticker on the skin (like morfine stickers), that would be easier. But you also need to keep in mind that the stuff needs to be heated to about 210°C (for PLA plastic, biodegradable and food safe, and sometimes also used in medical implants because of that). So the medication should not degrade at that temperature. However, personally, I wouldn't want to have any particles injected. Never. If they accidentally get into the blood stream, they will block the blood transport to the heart, brains, eyes, organs and whatever e
  17. Hello, First: check if your print bed is very close to the print head, when printing the first layer, so that the first layer is squeezed well into the bed. Otherwise, no bonding method will work. Then I recommend that you start printing with the default values for PLA: 210°C nozzle temp, 50mm/s, 60°C bed temp. These are a good all-round average. And fine-tune later on. For good bonding, I always wipe the glass plate with very salt water prior to printing: - First clean it with pure tap water only (no soap, because that reduces bonding). - Then moisten a tissue with very salt water, and w
  18. Ha, okay. That makes things a bit easier. When I hear the word "laser", I still think of those big, old devices we had in school, emitting light that runs for 100km in a knife-sharp beam. Sort of scrap military or scientific stuff. But that said, I still would wear very dark laser-safe glasses, as long as spare eyes are not available on the market...
  19. Hello Cloakfiend, Out of curiosity: have you ever tried filling your artwork with glued sand or little stones? (The sort of very small stones that they also use in modern composite floors, I don't know the correct English name.) This will add weight and improve mechanical stability. And a heavy piece of art feels more valuable than a lightweight one. A dry mix of composite glue and rough sand or small stones would be best, I think, just like they do on floors. This stays in place easily, and does not heat up when curing. (Don't use pure liquid composite glue alone, this gets extremely hot: I
  20. I am not sure if it is a good idea to add laser cutting/engraving stuff to a machine that is not designed for it. You would first need to completely cover the machine with a laser-safe enclosure, or else it may be cutting/engraving your skin and eyes too. A laser that can cut through metal, surely can cut through skin, light sensitive eye-cells and even skulls. And then the rays bouncing around still may be cutting/engraving the inside of the machine: the print head, rods, belts, glass plate, aluminum heated bed, side panels,...
  21. I don't know the official specs, but the cards in my two UM2's are both SanDisk 4GB SDHC cards, Class 4, and both were delivered with the printer from Ultimaker. They are from begin 2015. The "class" is about the maximum data transfer speed that the card can read or write, which is important for HD-video (usually requires Class 10). But I think for 3D-printing anything will do, since everything else in the system will be slower anyway...
  22. Thanks. I saved this as PDF for the future (=easier to find back than searching through hundreds of posts). We can never know too much usefull methods.
  23. For PLA a difference of 10°C in bed temp can make a huge difference in bonding: 60°C is optimal and very strong. At 70°C the model becomes too flexible, so corners can be peeled off the build plate due to warping forces in case of difficult models. At 50°C bonding is clearly less strong, and a few corners may start to lift. At 40°C models may suddenly pop off halfway the print. At 20°C there is no bonding at all. At least, this is my experience, but your's may vary if your circumstances do vary. For other materials, temperatures will be much different, but I think the same effects will play.
  24. I don't need it for PLA, but I am going to keep this method in mind for when I would print other materials (I doubt if my salt method would work then), it seems interesting. I haven't seen Elmer's wood glue here in Europe though (but I haven't searched either, so just from memory). Is it that kind of general liquid white honey-like glue that is also sold as general kid-safe wood/paper/cardboard glue, and is water-soluble? Do you remove the glass plate to apply it, or just apply it while in the printer? And how well do parts come off after cooling down, do they pop-off from themselves, or do
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