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geert_2

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Everything posted by geert_2

  1. I think printing little test plates of 10cm x 2cm x 1mm would do. This doesn't waste too much material. Design them with a hole so you can hang them on a line, like a decoration. Even better: print two copies of each, and keep one stored inside in a dark space, to compare. Then every month you could compare the plates visually, and flex them to feel if they got brittle and if they snap under pressure. In some materials UV-damage may be visible, but in some it is not, and the item just falls apart when you flex it.
  2. I don't have any experience with replacing the heater and sensor on these printers. But I did build a couple of electronics machines in the past. So my comments below are educated guesses, but not necessarily correct or complete. Probably the heater got red hot because you disconnected the sensor from it. So the feedback-loop was broken, and the system kept on heating and heating, because it did not sense any change in temp. I don't know how long these heaters can withstand this without burning out? If - after assembling everything again - the temp overshoots a lot, with identical components
  3. To improve UV-resistance, maybe you could use black or highly opaque materials? This prevents the sunlight and UV-rays from penetrating deeply into the material. That was a reason they originally started to make car tires black by adding carbon in the old days. Originally they had the light brown natural rubber color. Of course, manufacturers use synthetic rubber now, and they add lots of other things into the mix (e.g. silicon), so I don't know if they do still add carbon. Disadvantage of black is of course that it accumulates more heat. So it definitely won't work with PLA. I guess you
  4. Concerning PLA smoothing, if you haven't done so, I would recommend that you read the thread about PLA smoothing created by user cloakfiend. This has lots of good info and photos (so you can verify the results). He is the specialist on PLA-smoothing. This thread contains about all that is known about this subject. It should be this: https://ultimaker.com/en/community/10412-acetone-finishing-on-pla
  5. You can import SketchUp files (skp-files or something, not STL or OBJ) directly into the freeware 3D-editor DesignSpark Mechanical ("DSM"). If you do that with fonts created in SketchUp (with the characters as vectors only, or as surfaces, not yet 3D-models) and then you try to make 3D-models out of them in DSM, you will see that in a lot of characters the vectors-ends do not match: there are tiny gaps. It are not closed shapes. In DesignSpark Mechanical this can be repaired manually by zooming in on the offending characters and vector-ends, and manually adding small vectors to close the gap
  6. As far as I understood, the basic reason is that ABS requires a very hot temperature to melt and fuse well. The new layers tend to cool down too fast, thus without proper fusing to the previous layers. You need to keep the temperature of the old layers way up too: close the front of the printer, switch off cooling fans, high bed temp, and don't print too fast. In combination with the huge shrinkage of ABS, this causes the splitting, or the coming loose from the build platform. ABS is good for injection moulding, but not so good for 3D-printing. If PLA would not be suitable for your model, yo
  7. I store all filaments in huge sealed boxes with a big (!) bag of disseccant, so they are dried and then stay dry. I use the sort of disseccant that is sold in car shops to dry car interiors and prevent condensation on the windows. They have a blue indicator that turns pink when the bag needs to be reheated in a microwave or other oven. For nylon, you should also put the spool in a sealed box with disseccant *while printing*: otherwise it may absorb too much moisture in only a few hours. This may require some bricolage: you need to make a spool holder, a small exit hole, and a holder for the d
  8. Another option would be to take a ruler and measure it. And then draw the thing in whatever CAD program you want.
  9. I have printed 10mm x 10mm x 10mm test cubes in that way: just set the wall thickness to more than 5mm indeed (in my case), and it spirals layer per layer. Then it prints only walls without infill, until the whole object is filled with wall. If your object would be larger than 10mm diameter, adjust wall thickness accordingly. However, the center of the spiral does not come out well: the nozzle stays too long in that little area, develops too much heat, and it has to slow down too much to go around the tight corners. This results in ugly blobs and overextrusion in the center of the spiral. Th
  10. I tried all sorts of keychains in PLA, PET and NGEN, just to get an idea of the durability of these materials in daily use. PLA gets harder, more brittle and breaks under too much stress. PET deforms and then also breaks. NGEN snaps also. They seem to be about equally strong in normal use. If you want the part to last, you need to design in methods of stress relief. For example, give all parts enough room to move around freely, so they do not get stuck in weird angles and break, when you sit on it, or when you pull it out of your pocket with too much force. I haven't tried flexible materia
  11. Have you tried this? Remove the bowden at the print head. Heat up the nozzle manually to the normal print temp. Check if the little back fan works indeed. And then manually feed filament into the teflon coupler and nozzle directly, without bowden tube. Keep an eye on the temperature. Does that go well, and keep going well? Or does that cause jerks, stops, irregular friction, or whatever? If you can feed 10cm of filament through smoothly in this way, that should exclude the nozzle and coupler from the cause, I think. And what happens if you disconnect the bowden tube at both ends, and manuall
  12. Thanks for the feedback, I appreciate it. I have never used Faberdashery PLA, so I can not comment on that. But it is entirely possible indeed that some PLA-brands are more sticky than others. If they stick reasonable to an untreated glass (no glue, no salt, nothing), then they are likely to stick better with the salt method too, in my experience. And vice-versa. Concerning the glue stick: it seems that different brands give different results. For my difficult models, I had poor results with the default glue stick in the beginning: corners did lift, but fragile models got damaged when remo
  13. I think they look really great. They look like high quality casts rather than 3D-prints. Concerning a few occasional imperfections: if you look at bronze statues, they also contain lots of imperfections: scratches due to removing moulding or welding seams, circular defects from the removal of support pins from the moulding, sanding marks, washed-out details because of the polishing, and so on. While it may hurt to the eye because you know they are there, I consider it part of the job.
  14. I have never changed jerking or acceleration settings, so I can't comment on that. But generally, printing slower (and thus also cooler) greatly reduces this effect: for small high quality parts I use 20 or 30mm/s instead of 50mm/s. Also, some materials hide this better than others, if they are slightly translucent. But not too translucent, because then you start to see the inner print lines too much.
  15. In my UM2 (non-plus) with original firmware, the calculation goes wrong when the tune-menu is kept open. For example when manually adjusting temp. If this tune-menu has been open for some time, then the remaining time sometimes increases to hours extra (on a print of a few hours). It looks like the calculation is paused or so? After the tune-menu has been closed, remaining time slowly recovers to reasonable values. But I don't care, since it doesn't affect print quality.
  16. You are welcome! In my experience, helping others is well spent time: it requires me to think about things, and to see the situation from lots of different viewpoints. Whenever a solution is found (it doesn't matter who finds it, me, one of the other people here, or the original topic starter), we also know that anwer and we can use it four ourself. So this is a very fast way to learn, with a high "return on time investment".
  17. If you would like to try it, maybe you could ask a couple of manufacturers to send a few worthless scrap parts with defects or so, for free? Just to evaluate the surface finish and quality. I have also wondered if this is a layer of metal, or metal flakes, chrome powder, or some special optical effect in plastic? But it seems that it has to be covered with a sort of varnish, so probably won't be conductive afterwards. I also wondered about scratch-resistance: better or worse than normal paints? The old method in which a shiny chrome layer was put on with vapor, in headlamp mirrors, was ext
  18. This is for an UM2, but maybe it can be used for an UM3 too? I disconnect the bowden tube at the nozzle, and pull the tube out. This breaks the thin strand of filament. Then I move the filament forward a bit, and I cut off the irregular tip like this: And then I manually pull the filament out from the back. Sometimes this can be done while the printer is on, but sometimes the motors block this, and I have to switch the printer off. In this way I never have pieces getting stuck in the tube or feeder. Of course, I learned this the hard way. Then I do one or more atomic pulls to clea
  19. Hoi Sander: the concept of spanners that grip on the flats of bolts, instead of on the corners, exists for years in hardware tools. Especially in car shops, since those bolts and nuts get corroded and dirty, and require huge forces to remove. But then it still takes someone to have the bright idea to teleport this concept to 3D-printing, where it is equally needed. There do also exist similar spanners that can handle both metric and imperial bolts and nuts, based on this concept, the so-called "metrinch" spanners. Next time I am in a hardware shop, I will pay more attention to it. For e
  20. I never go over 210 to maximum 220°C for PLA. This would cause the PLA to get burned, thus worsening the amount of burned material inside. If you have printed with PET or ABS before, and you do the cleaning with PLA, you might try higher temps indeed to melt their residu, but only for a very short time. If you use nylon to do the atomic pulls, you will need a higher temp. It depends on the materials. The brute force of the traditional atomic pulls is indeed why I developed this more gently method. I did displace the nozzle and teflon coupler a few times, and I worried about bending the rods,
  21. "M4" defines the thread's outer diameter in millimeters, in this case 4mm. Thus a bolt with an M4 thread will just slide in a hole of 4mm diameter. An M6 will slide in a hole of 6mm. The thread will fall through, not lock. Thus the inner thread of a nut is smaller, to get the screwing action, but I don't know the dimensions by head. The outer dimensions of the hex heads are bigger: about 7mm from flat to flat for an M4. Google for "metric thread dimensions", for tables with the full specs. These also show the required drill sizes before tapping the thread. If you want dimensions of plast
  22. To make the site faster, and to reduce your server-load, I think it might be a good idea to make all animations and all films "on-request", instead of autoplaying. Provide a button which the user has to push. And only then the film or animation should be loaded from the server and executed. Provide a static low-resolution JPG-image as placeholder: this loads very fast. The first time people arrive at your site, they will want to see the animations. But after they have seen it once, it becomes an annoyance. Also, mobile devices may not have enough resources and RAM to play videos or big ani
  23. A bit late, but still: in car tuning shops, they do have spray paints that give a chrome or gold effect (or any other desired colors with mirror-effect, as in christmas balls). On Youtube you find a lot of demo videos. Search for "spray on chrome", or "spray paint mirror chrome effect", or similar. It seems to consist of cleaning, spraying on an activator, rinsing with water, spraying on chrome, rinsing with water again, spraying on a sealant varnish, rinsing, drying with compressed air. It also seems to work well on flexible materials, even leather. For example these:
  24. On my computer they work. Windows 7 Pro, SP1, Pale Moon browser (=derived from Firefox, but still has the menu-bar and statusbar). But it is going very slow and stuttering, and the CPU is at 100%. So it seems that they consume a huge amount of resources. This might be too much for some systems, or if running in a virtual machine. Are these defined as videos, or animated GIFs? If videos, I think it would be best to remove the "autostart", and add a start-button per video. And set the video to play once, and then require another manual restart if the user so desires. This would greatly reduc
  25. I am glad the salt method works for you too. @prb4: try this link: https://www.uantwerpen.be/nl/personeel/geert-keteleer/manuals/ First thoroughly clean the glass, and then clean again with plain warm tap water only (no soaps, no window cleaners). This outside of the printer, of course. Then I just put a few drops of salt water on a paper tissue, and gently wipe the glass plate. Gently keep wiping while the water evaporates. So it leaves a thin mist of salt stuck to the glass, nice and equally distributed, but almost invisible. It looks like the glass is just a bit dusty. On the second
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