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geert_2

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Everything posted by geert_2

  1. I only use it in our university laboratory, and only for a minutes or so, until the model is filled and the gypsum is distributed nicely. (Although, since 3D-printing, I haven't used it anymore.) This sort of noise is more acceptable in a lab. But in an appartment, people would notice it a couple of floors away, just like drilling into concrete walls. Unless it would be placed on thick antivibration mats. The gypsum first looks like dry clumps of cement, but when you switch on the shaker, it starts flowing smoothly, very similar to silicone for mould making or lava, into all corners of the m
  2. What about just keeping the old forum in use, parallel to the new one being set online? Until the new one is stable? Seems like the easiest thing to me? Are you planning to convert all existing threads to the new forum? Or is the old forum going to become read-only, as a sort of archive of accumulated knowledge?
  3. I did sand a tiny injection needle down to 0.39mm, after cutting off the sharp point. So it just fits into the 0.4mm nozzle. After doing an first atomic pull, I carefully insert that needle from below into the nozzle, to push out any remaining debris in that small opening. And then I do another atomic pull to remove loose debris. In this way the opening keeps its internal diameter of 0.4mm. Apart from that: I don't really do "atomic pulls" anymore, I rather do "atomic turns": instead of brutally pulling the filament out, I first let it cool down much more, until 25°C. And then I wiggle and t
  4. This is the gypsum shaker I use, two speed. Small but heavy. Occasionally, it is capable of bringing a whole wall into resonation, like a pneumatic concrete drill. There is no way to get a *thick* gypsum paste flowing into fine teeth details without a good shaker. That is why I think it might be beneficial here too, if you have flowing problems. For dental models to be strong enough, the gypsum needs to be a very thick paste like cement or choco (it feels like somewhat inbetween). It is way thicker than honey or syrup, but less stiff than most natural clays. So they can not use a "cream
  5. It is not a font. It is a design I made in DesignSpark Mechanical, thus flat surfaces that I can pull into 3D-shapes. Created on a 0.25mm grid. I don't mind other people using it, but you do need DesignSpark Mechanical, as it is in its native RSDOC-fileformat. I will put this character set online (probably begin next week), together with some other stuff. The way I use it, is by copying and moving required characters into the desired text, and snap them on a 0.25mm or 0.5mm grid for alignment. And then I pull this into 3D-text, and apply it to the model, by adding or subtracting as require
  6. I have no idea what IRC is... I can still work with the current forum, provided I take the route "Community > Top categories > and then chose some category". Not optimal, but usable.
  7. What if you print a test block of 20mm x 10mm x 10mm, 100% filled? And then 20% filled? Is there any difference in surface quality? I have seen similar blobs and gaps in some PET materials, when they needed to close big gaps: the material was too rubbery, instead of creamy. And thus, instead of pulling a nice line like PLA, it contracted into a blob on the nozzle that gets deposited on the model as soon as it reaches the next wall or so. So a 100% filled model would go well, but a 20% filled model would come out ugly with gaps. Bridges also would not work well. I have no idea if this is
  8. It really needs to vibrate hard to get a thick gypsum paste to flow well. Like a small combustion motor, a one or two cylinder engine. Putting the models on top of a washing machine will not work.
  9. Forgot to say in my previous post: raised text (lines on top of a surface) usually comes out better than recessed text (hollows). In recessed text, corners tend to be cut off due to the elasticity of the molten material while printing, and the printer always has trouble with characters like N, R, K, 9, etc... Especially the capital N: the 0.4mm nozzle can't get into the sharp corners (remember that the characters are only 3.5mm high), thus this gives a very deformed diagonal line. In my tests, printing text on side-walls gave far worse results than on the top, because all corners are round
  10. If I go via "Forum" I also have these problems. But what still works well is to go directly from the top menu "Community" to "Top Categories", and then "General", "The art of printing", etc... So I have to avoid the direct path to "Forum". Browsing the forum without loging-in, and then only log-in when I want to reply, also works fine, but is not handy.
  11. Thanks for the video. Yes you are right: a piece of art needs sufficient weight to feel like art. Otherwise it feels like a cheap plastic toy, even if it looks identical. A few questions: why not use a 20ml or 50ml syringe? Then you can inject it in one shot. In Belgium such syringes are available from our local pharmacy (way cheaper than from companies that sell laboratory equipment). Instead of a needle, have you tried drilling a bigger hole, and using thin aquarium PVC tubing? Or no needle at all, just the syringe nozzle? Then you can make the mix thick like cream, and still have it ex
  12. I wipe the nozzle's outside with silicon oil and PTFE oil sometimes. In the beginning I had to do this more often, but now I do it occasionally. It reduces accumulation somewhat, but does not totally prevent it. It also depends on the material you use: PET caused more problems than PLA for me. Also, if you have overextrusion, this happens more, as the excess material accumulates on the nozzle. Printing cooler and slower also helps a bit for me. (This is for an UM2 with 0.4mm nozzle.)
  13. Last year I tried all sorts of small text, both positive text (lines on top of a surface) and negative text (hollows). The characters need to be ca. 3.5mm high, and each leg or line needs to be 0.5mm wide, for acceptable results with a 0.4mm nozzle. Character height/depth is not much of a problem: 0.2mm to 0.5mm is fine. Print slow and cool: 190°C and 25mm/s for PLA, for example.
  14. SketchUp is good for getting an idea of how to use a 3D-modeling interface, since it has a very simple and intuitive interface. Use the last free versions (was that 7 or 8?). But do *not* use it for 3D-modeling for 3D-printing, since the models contain too much defects. The walls don't close and are not "watertight", so these models are not considered solids, but hollow models with infinite thin walls, and obviously you can't print that: it is a mess. I use DesignSpark Mechanical since it came out. It is excellent for geometric shapes, thus based on straight lines and curves, such as machine
  15. If this is Ultimaker or colorFabb PLA, have you tried my "salt method"? Also read the section about cleaning. See: https://www.uantwerpen.be/nl/personeel/geert-keteleer/manuals/ I have printed quite a lot of long models with holes, similar to yours, without any problems. They usually are 100 à 150mm long, 10 à 15mm wide, and 3 à 6mm high, with sharp corners. The only things I can not print are inverted pyramids and prisms, with a very small base and huge overhangs. Here the warping forces are to high for the very small base. (Actually, I thought you were printing in ABS, with that amou
  16. If Ultimaker makes *very* sure that all Cura-versions can work parallel, also early developer versions, without influencing each other's settings, then doesn't that solve the problem? When they are installed in totally different directories, based on version number and sub-numbers? I think this is already the case, although I don't know about the very early experimental versions? Then you can just keep a couple of the most stable older versions on your system for production. And you can freely experiment with all new features in the nightly builds, and give feedback. A version that is stab
  17. After is easy: just measure the weight of the model. If you regularly compare this real weight with Cura's estimates, then you will get a good idea of its accuracy for your type of models, and for the requirements (spare amount) before starting.
  18. If you want/need custom supports, I think it is best to design them in your CAD program. Then you can design all fine details as you wish. "Custom" supports can not be automated anyway, due to the zillion different shapes, materials, requirements and personal preferences. If Cura has to do this, then this would divert developer attention and manpower from "trying to develop the best slicer", into developing a mediocre 3D-editor + slicer bloatware. At best in Cura there could be options like "place additional supports here" and "remove supports here". But this still doesn't give any real custo
  19. Obviously, hardware stores can't beat that ebay price. Last week when walking through a Brico shop, I took a quick look at the prices. An "industrial" bottle of 20ml cyanoacrylate costs 13 euro (Belgium, Europe). Compared to 6 euro for 2 little tubes of 3ml of the same product, next to it. I think the brand was "Bison".
  20. I have no answer for your question. But if you would find one, you might run into other problems, depending on the size, nozzle temp and print time of each of these extensions. If these extensions are too small or the print temp rather high, it might not get enough cooling when the nozzle is staying too long in the same area. So it might deform as in the photo below. I think your dimensions are on the edge of what can still be done: I guess it should go well if you print rather cool. So I suggest you first try if such deformation happens by cutting the model in pieces, and only printing one
  21. I think you also need to specify which bonding method you use (also describe how applied), how you clean the glass bed, which printing materials you use, and how you calibrate the bed. Because these might be the problem.
  22. If your model consists of geometric shapes, you can do this in DesignSpark Mechanical. This is a freeware 3D-editor for geometric shapes. I have used this feature once to rotate text around a cylinder. It uses the "project" feature, but I don't remember the exact procedure, so you will have to google a bit. There are training videos or tutorials around the internet showing it.
  23. When it finally started running, did the fan run smoothly? Or does it make a lot of noise and a sort of grinding sound? If the latter, its bearings might be worn out, preventing it from starting? After a while, it does start, but only at low speed, and wobbly. I have seen this quite often in computer fans, in the old days of Windows 9x and Pentium I, II, etc... If it are the bearings, replace the fan. You could lubricate the bearings to get a few more days/weeks/months out of it. I have done so by making a small hole in the silver cover plate with a needle, and then injecting a little bit of
  24. I once tried welding 2.85mm pieces manually. It works, but it is cumbersome. First, you need to design and print a sort of clamp or guide in which you can keep both ends of the filament aligned nicely. So that they match well while welding. Then, cut off both filament ends in a 90° angle. Insert them in the clamp/guide. Heat a metal plate, and old knife, or a spatula in a flame until well above melting temp of the filament. Insert that hot metal inbetween both filament ends. Push the filament against the metal slightly, so it melts. Remove metal plate, push filament together, and let cool
  25. This was my oversized design. Although technically it worked, the uglyness did outweight the benefit, as you can see. The original button raised 5mm also does the job well enough.
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