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geert_2

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Everything posted by geert_2

  1. In the beginning it really was a problem for me indeed: I often have difficult prints: long, 100% filled, with chamfers or roundings at the bottom, 5 to 15mm high. These excert a lot of warping force, even when using PLA. Printing on bare glass sometimes worked in cold dry weather, when it was freezing outside. But it never worked in rainy weather: then the filament would curl up immediately. I disliked the glue-stick methode: too messy, and bonding was still poor. And I could not use blue tape, since the underside of my models had to be totally flat. So I had to find something else... It took me some time and some testing to discover the "salt method": now I just wipe the glass plate with very salt water before a print. When dry, this leaves a very thin, even mist of salt stuck to the plate. Since then I have no more problems: models stick very well when the glass is hot (60°C), and they pop off by themself when at room temp (25°C). I only print with PLA, so I don't know for other materials. Also, I don't know why it works, but it does. Could it be surface tension? Soap decreases surface tension and decreases bonding. So I thought salt might help since it works in the opposite way of soap: it increases surface tension. Other things that might play a role could be surface roughness, or electrostatical charge?
  2. For a better adhesion to the glass plate, when printing with PLA, you might try my "salt method": - Clean the glass plate with handwarm pure tap water only, no soap. - Wipe the glass with a tissue moistened with very salt water, and gently keep wiping until it dries and leaves a thin, even mist of salt stuck to the glass. - Then print your model with the glass heated to 60°C. This gives a very good bonding when hot. For me this works much better than using the glue stick, or than printing on bare glass. I never use brims or rafts, even not for difficult models (except for inverted pyramids, thus top-down). I have only used it with PLA. - After completion, let the glass plate cool down to room temp (25°C), and then the models will pop-off by themself. No force required. See the full manual and tips and photos at: https://www.uantwerpen.be/nl/personeel/geert-keteleer/manuals/ Let us know how well it works for you. Geert
  3. I have my printers installed in a laboratory fume extraction cabinet (which I had anyway), so no need for this. But this thing looks a bit overkill to me, and it makes it a lot more difficult to reach the printer and to tune it while printing. If you only want to extract fumes, without enclosure, you might also consider trying solder fume extraction equipment. RS-components and Farnell should have them. Or maybe a simple kitchen fume extraction would also work? At least if you put another filter in it (maybe active carbon could work?).
  4. Maybe you can get it done with newer versions of Cura, but for older versions (I use 14.09), the following might be a work-around: if you designed these parts or you can open them in a 3D-editor, you could arrange them in the editor, and save that composition as a new design. Then Cura will consider this as one single model and print it. I am not sure why Cura draws the grey unusable area around models, also in all-at-once mode, but I guess it is to avoid the nozzle bumping into other model parts when moving from one part another, when combing is off.
  5. The biggest advantages of the "salt method" are: - It is a very comfortable, clean and fast method. - Since using this, I never had to take the build plate out of the printer. - And it sticks very well for PLA when hot (better than glue or bare glass). But it has no bonding at all when cold (less than bare glass). So I have no more worries about warping, and I never needed brims, rafts or whatever since using the salt method. I haven't tried any other filament than PLA, so if you try, please let us know. I am very interested in the results, negative or positive.
  6. Hello, And what is the result if you just manually extrude material? Thus "Move material" in an as smooth as possible way? This pattern sort of reminds me of LCD- or LED-display panels where a couple of X or Y datalines have bad contacts. Or an digital-analog converter where a dataline is broken. If you haven't done so, I would suggest checking all connections, all wires, for intermittent broken/bad connections. Especially those that are subject to movements (near the print head), and that are related to temperature and extrusion: temp sensor, heater, feeder motor. It could be broken solderings or wires, or a damaged connector pin, or so. This can be very difficult to find, since it is intermittent. What part of the printer have you worked on just before the problem started, and what was changed or touched at the exact moment before the problem appeared? Geert
  7. Could that be a slicer problem too? Or wrong settings in Cura or whatever slicer you use? For example a check box that got (de)selected inadvertently? This weird but very regular pattern makes me think of those art lamps that do only print the 3D-mesh of a model (the "fish net"), but not the infill. Or a defect in the SD-card or card reader, where it only reads data partial, but skips other parts? (Try a different card, or remove it a few times to clean the contacts.) Has the exact same gcode-file worked well in the past, or did you slice and save the gcode again recently? If you manually extrude material ("Move material") by rotating the wheel smootly, does that extrusion flow in an equal, nice stream? Or is that intermittent too? If equal, it looks like software to me. If intermittent, it looks like hardware. I am just wildly guessing here, but it might give new ideas? Geert
  8. If you correctly save your designs in the native DesignSpark Mechanical format (RSDOC-files), then there should be no reason why couldn't edit them afterwards. I have made hundreds of changes to my existing prototypes. So, could you verify that you save each design as an RSDOC-file first? If that is okay, but you still can't edit existing files, then the problem is probably somewhere else: wrong user rights on a file or directory? If so, try copying them to a FAT32-formatted device (USB-stick), and back, that removes all user-rights. I would suggest for each design and each version of a design to save the files as follows: - Always save it as an RSDOC-file first (double check you have the correct format, RSDOC, since DSM defaults to the last used save-format). - Then save it as a JPG-file: this makes it a lot easier to browse through your designs with an image viewer and select the correct item for further editing. Very handy if you have hundreds of files. - And only then save it as STL for printing. You can't edit STL-files in DSM (or at least not without a lot of problematic tricks, and with loss of design-info). Geert
  9. When reading 3D-printing forums, and based on my own experience, the problems that do arise most in 3D-printing are related to: - underextrusion due to teflon coupler worn out, - underextrusion due to filament wound too stiff (works like a spring) and its bending radius being too narrow (high friction in bowden tube and nozzle), - temperature too low or too high for a given filament or model, - speed too low or too high, - dirty nozzles, - cheap filament with varying diameter or included debris, - bonding problems of model to build plate, - build plate incorrectly leveled, - etc. I don't see how you would solve these problems online? Because these are the causes of failed prints. Slicing rarely is the problem. And only very occasionally are supports the problem. Finding models to print also isn't the problem: there a tons available, even for free; but the most fun is to design them yourself. That is why we 3d-print after all (otherwise we would buy these things directly on Shapeways or so). If you "solve" a problem, but it does not go away, then the "problem" you identified was not the problem. Or the solution you applied to it was not the solution. Or both. Usually both, because if the problem was not the problem in the first place, then obviously the solution won't be the solution. You see? I have the feeling that this rule applies here too. And a totally "empty" homepage with only an executable to download? But no explanation at all? No company profile, no business owners, no address, no tax registration numbers, no phone, nothing... So, no thanks. This is not being sceptical, this is just plain common sense. I am not saying that your intentions are bad, because I don't know. They could be honest. But at least your communication is way too bad to trust it: it is not enough that you know what you are doing, and what the benefits are; you should also communicate that to potential customers. Communication should provide good understanding, show examples, list all technical facts, troubleshooting tips, references, company names, adresses, official registration info, contact info... Geert
  10. I usually design any supports by myself in the CAD program. Image: support test: trying various distances of support to overhang. Ridges are 0.5mm high and 0.5mm wide, separated 1.0mm from each other. Vertical gaps are between 0.2mm and 0.5mm, as indicated. Designing my own supports makes it easier to adapt them to the specific model: - For large areas, I want a bit more distance between the support and the model, so it is easier to peel off, e.g.: 0.4mm. - For small and high detail models, a distance of 0.2mm works fine for me. This gives a rather smooth underside on the overhang, much better than with the standard supports. Less than 0.2mm is not recommended, then it becomes too hard to remove without doing damage. - A bit below the overhanging plane, I design a thin solid layer in the support, usually 0.5mm thick. On top of that layer I add ridges of 0.5mm wide, 0.5mm high, with gaps of 1.0 to 1.5mm in between them. The first layer of the overhang will print 90° rotated from these ridges, in my experience (verify in Cura Layer View). See the picture to get the idea. The numbers on top indicate the vertical gap in mm between the top of the ridges and the overhanging model. By using ridges the support is much easier to remove, in my experience (so the vertical gap can be smaller, thereby increasing quality). - To make support removal easier, if the model allows it, I design tabs and hooks into the supports, so I can pull them out with pliers or other tools. I also try to provide openings for cutting any unwanted strings with a knife. Plus vertical openings, to separate various parts of the supports (so they don't turn into one solid block that can't be removed). On those parts of the support where I need a good grip or need to pull hard for removal, I make sure they are strong enough. Ideally, I try to design the support so that I can cut it loose (cut unwanted strings and hairs), and then pull it out in one shot, without hundreds of little pieces still sticking to the model. In the shown model, I can stick a plier in the supports and pull each part out easily. - In some cases I just place a lot of layers on top of each other as support, each separated by a gap of 0.5mm. Thus: a solid layer of 0.5mm, then gap of 0.5mm, then next layer of 0.5mm, next gap of 0.5mm, etc... And finally a layer with ridges on top. In this way, I can peel off layer by layer. It just depends on the model, its size, the required acuracy, the deadline, and my mood of the day (if I want to experiment or not). I have also seen several models made by others with custom supports. The standard supports are good for general use. But for specific cases, I think it is better to design your own, since there is no standard that suits all. Geert
  11. First clean the build plate with luke-warm clean water only, multiple times. No soap, no detergents. Then gently wipe the build plate with a tissue with very salt water. Yes, salt. Gently keep wiping until it dries and leaves a thin mist of salt stuck to the print bed. Then print on a heated bed at 60°C. I would recommend printing with the biggest surface downwards, as in the second photo. When hot, the model should stick rock-solid to the bed. After cooling down, it should pop off without any force. For me, this "salt method" has worked very well for over a year and over a 1000 models now, often difficult models. See the full manual with pictures at: https://www.uantwerpen.be/nl/personeel/geert-keteleer/manuals/ I have only tried this with PLA. I do not really expect it to work with other materials, but of course, feel free to try, and let us know whatever your results are, good or bad. Hope this helps. Geert
  12. I guess you already did this, but just to make sure: could you verify in Cura that the checkbox "Enable retraction" is checked indeed? Then verify in Cura, in Layer view, that extraction is active (=small dark blue vertikal lines). It could have been disabled accidentally, or on purpose to try something, but that you have forgotten to enable it again? Geert
  13. Is it possible to install (and uninstall) different versions of Cura in parallel, without them influencing each other at all? Thus also without automatically importing any settings? I could not find any info on this in the manual or FAQ. I would like to try the new versions, but without messing up my working version (Cura 14.09, on Windows 7 Pro, SP1), which I need for production of prototypes against deadlines. So the existing setup should remain stable, even though it may be "old". If not possible, what about adding it in future versions, For example by offering the following radio-button options during installation: O Update existing installation O Install the new version independently in parallel And if the user selects the "independent" option: O Import settings... [select Cura version to import from] O Do not import anything, start with factory defaults Something along this line? (I haven't tried running it in a virtual machine yet, but with the limited amount of memory, 3D-acceleration, and disk space available to virtual machines, that might cause other problems. Geert
  14. If the problem is that in mid-print, the print bed suddenly moves down, but the printer just keeps printing as if nothing happened, then this could be caused by the motor drivers (amplifiers) getting too hot. Then their temperature protection activates for a few moments, so the stepper motor gets no more current, and the built plate falls down a bit. There has been a recent post on this in the hardware section: https://ultimaker.com/en/community/20998-ultimaker-2-motor-drivers-overheating Could that be what you are seeing? Geert
  15. That is really cool. I am actually surprised that it works without leaking everywhere between the seams, on this small scale. Geert
  16. - I would prefer the list of posts (and the lists of forums) to be more dense, thus with less vertical white space in between them. And with more items listed on one page (or maybe user-adjustable in our profile?). So that it is easier to get an overview. The amount of information that is presented per item is okay. - I really don't like the blue pop-ups jumping over messages before I am logged in. These days a lot of people surf by opening in the background 20 posts from a list, by middle-clicking each. So, then I have to close that same blue pop-up 20 times, if I forgot to login first. Thus usually... This is really annoying. Most of the time the blue thing also pops up while I am busy logging in, so I have to start all over again. I would recommend throwing that out completely. So if you want to pick only one item from this list, take this. - The Sign-up button could say "Login/Sign-up", and could default to the login screen, since people have to sign up only once, but after that they have to login many times. Maybe there is a faster way to login, but I haven't found it. But I haven't searched either. - These forums contain a lot of very valuable posts and tips and tricks, very educative. But sometimes they are difficult to find, as they get snowed under tons of new posts. The best posts are worth converting into manuals. What would you think about a forum named "Manuals by users", or something similar? Where only those manuals are listed (after approval), but no discussions? Just a long list of Manuals / Tips & trics only? - I like to print valuable posts (to PDF-file) and store them locally, in my directory 3d_printing_tips. But the forum pages are not easy to print, so I have to copy and paste everyting into a text editor, clean it up, then print to PDF. If other people do this too, maybe you could add a print-CSS sheet to the website that removes left and right side panels, and cleans up the body text for better printing? But this has no priority. - Personally, I prefer very simple menus in the old style, like on this site: "www.interthk.be". (That's why I made it that way, even though it is very primitive and old-fashioned, but I just like it that way.) Or menus as on the GRC-site: "www.grc.com", which has very nice, very compact, but very modern pull-downs. Also very minimalistic, so that leaves a lot of room for the real page content. This is probably the best I've met (although not the most beautiful). You might want to check that out. The point is that I have trouble finding my way in these modern menus with "hamburgers" and lots of other meaningless (to me) icons. As in the recent Firefox-horror (so I switched to Pale Moon). But I can imagine that younger people - or mentally younger people - see things differently. Anyway, the good things are: (1) the Ultimaker forum does exist. And (2) it does work well technically. And (3) it is used a lot and contains good info. I appreciate that very much! So, don't throw these good things out.
  17. My first thoughts: - Something is scratching the case, as neotko says. - Or something is stuck between moving parts (slide blocks or wheels) and the case. - Or the rods and slide bearings are so terribly dry that they can't move at all, and start making a screeching sound. Like in cheap cheap computer fans, with worn-out bearings. But here on a lower frequency. If the rods feel totally dry, try gently lubricating them (but don't pour oil on the rods; do the oil on a tissue, and use that to genlty wipe the rods). - Or some debris got into a bearing and almost blocks it, or a broken bearing. - Or a severe mis-alignment if something came loose or if the printer got dropped or hit during transport. Try borrowing a stethoscope (like doctors use to listen to your breath) to find out where it comes from exactly. Car dealers and repair shops also use this to locate weird engine sounds (I saw one using it on my car once). Or try making one yourself from PVC tubes, it might work.
  18. If only fume extraction is important, you could look into soldering fume extraction systems? In the old days we had a sort of desktop bureau lamp with built-in fan and active carbon filter. No bigger than a normal desktop lamp. So you had a lot of light when soldering, and the fumes were taken away. But I don't know if active carbon filters out PLA and ABS fumes also. Just blowing them around, wouldn't improve safety... (My Ultimakers are in a chemical fume extraction cabinet in our lab, since I have it anyway. Doesn't seem to cause problems with the draft for printing PLA.)
  19. I found that stringing and "hairs" do mostly occur when: - printing rather hot, - printing fast (which requires printing hotter), - when increasing the flow rate and overextrusion happens, I noticed that strings occur when filament is leaking out of the nozzle opening. And hairs occur when molten residu is accumulated on the nozzle tip, and is sagging and touching the print. Or when the previous layers are overextruded or curled up, and the side of the hot nozzle touches these raised parts. Most materials string more when hotter. So, as yellowshark says, I would suggest you try printing slower and cooler. Print the same object once again just for testing, and keep watching it. Then play with temperature and speed settings. E.g. reduce temp in steps of 5°C, wait a few minutes and see what happens? I realise this is an older post, but it may help others in the future.
  20. I noticed that parts with big overhangs tend to curl up. The printer has to print part of those layers "in the air", so it has no good support. These overhanging edges can curl up quite a lot, even one or two millimeter. What may happen next, is that the print head brutally collides with these ridges, and knocks the print over. I have seen it happen in a testprint. Could this be the cause? If you have a compressor, you could try blowing cool air on the surface, to make it cool faster and get less curling up.
  21. It depends on whether your models are mainly geometric machine-like parts, or rather organic parts? To start with geometric models (machine parts), I would suggest you have a look at DesignSpark Mechanical, which is a limited version of SpaceClaim. Legally free. This is rather easy to learn, and you can find a lot of good tutorial videos online. For organic shapes, Blender is very powerfull freeware, but not that easy. Maybe you could also have a look at a modeler such as Form Z (www.formz.com), which is more geared towards architecture and product design? It is not free, but the price is still acceptable. Their user-interface is also quite easy to learn, very intuitive. And they have free trial versions. Probably also free student versions (requiring proof).
  22. We don't have one, but I have seen one in use at a local distributor last year (I don't remember the brand). I found it rather disappointing: it couldn't scan inside an empty cup, under armpits, under a nose, under a car model, in an open mouth,... All these very common things left huge open gaps and/or defects. And then, once you had the scan, you could not really work on it, it was a huge mess of mesh. It only worked well for very simple objects, which you could as well design in 3D. So, whatever your scanner model of choice would be, I would suggest that you go to a local distributor, and have him scan your typical objects. And let him go through all the post-processing, editing and cleaning-up in front of your eyes. I think that is the only way to know if it is good enough, and if it is workable for you. Also carefully verify that the scanner produces watertight solid 3D-models. Often 3D-scanners will only produce surface-objects (even with holes in it), that you can not 3D-print. These surface-objects may be good enough for rotating an image on-screen, e.g. for a game or for 3D-visualisation, but not for printing. You really have to see it with your own eyes, I think.
  23. Could this sort of problem be caused by long common ground wires, used for both power and sensing? Or something similar? So that some reference shifts up or down when a high power device (e.g. heat bed) is switched on and causes a voltage drop in these lines? I don't know the board schematics, so I am just guessing. Further, what part of the printer exactly causes the EMC-overshoot? Heated bed, wires, controller board,...? Could that be handled in a simple way by adding an (bigger) earth-line somewhere, or by shielding? In that case, might it be possible to officially say that: "On the condition that you modify your printer so and so, the bed-PID may be enabled"? Or would that violate the laws too?
  24. When doing an atomic pull, if you have a thick blob in the area where the nozzle meets the teflon coupler, this means the teflon coupler is deformed: it has become wider at the bottom. I had the exact same thing after a few hundred hours of printing. If you do a normal atomic pull (=with pulling very hard) you risk dislocating the nozzle or teflon coupler, or even bending the rods. I would suggest you try a more gentle atomic pull, as described in my manual here: https://www.uantwerpen.be/nl/personeel/geert-keteleer/manuals/ This has far less risk of doing damage, because it is specifically designed to prevent that thick blob, and it requires only very gentle pulling. But that of course does not repair the basic problem: the worn out teflon coupler. So I suggest replacing the teflon coupler too. Further, if you are near the end of the filament spool, where filament is wound extremely thight, I suggest you manually unwind a few meters of filament and manually straighten them a bit. Then let it roll up on the spool again, so that it is now sitting very loose on the spool. A bending radius of 30cm is optimal for minimum friction in the bowden tube. A straight filament is optimal for minimum friction in the nozzle. So a bending radius of 50cm seems to be a good compromise and works best for me. Found out by trial and error. Geert
  25. After each print, when I am in the neighbourhood and I hear the printer finishing, I immediately clean the outside of the nozzle while still hot, by using a thick (!) tissue. Also when doing an atomic method, I often clean the outside too. I refer to this as "wiping its poop hole", to avoid confusion with cleaning the inside of the nozzle (atomic method). This also gives cleaner prints, since there is no brown residu sagging and leaking onto the next prints.
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