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jonnybischof

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Everything posted by jonnybischof

  1. I'm still preparing these dfx drawings. They'll need drawings with some measurements and indications for material, thickness, surface quality / treatment and so on. I'll have a talk with the waterjet people when I ask them for a quote. If that works (using the window space for small parts), then I have some ideas for suitable small parts. But especially for smaller / thin parts, steel is perfectly suitable. And small parts (in quantities from 10 pieces and above) are quite cheap (cheaper than printed parts). Trowalised (tumbled?) chrome steel also looks very nice. The mailman disappointed me again today - my metal panels should have arrived, but they didn't :(
  2. Thicker, yes. Still you can bend 5mm aluminum by hand, and as alu is not an elastic metal it will stay like that instead of returning to it's flat state. The full panels (rear, bottom) are by far strong enough, but the windowed panels are weaker than you'd think. Of course, when you handle the panels properly all of the time, there won't be any problems. Not sure I understand what you mean. Do you mean if I put small parts into the space where the window cutouts are? That doesn't work when you get the stuff professionally made - 1 part per drawing...
  3. http://www.trinamic.com/products/integrated-circuits/stepper-power-driver Click "Download the TRINAMIC Product Guide (PDF)" All the important information about their drivers is there. The TMC2100 is a simplified product - much like the DRV8825 and Allegro drivers (but with more sophisticated features). The TMC260 is a more advanced part that has more parameters you can set, for example the slope control. It also has the StallGuard2 function which is one of the most important advantages over the DRV8825. What's also nice is that you can change the microstep setting at any time you like. You can do slow, super-precise movement using actual 1/256 microstep resolution, then speed up going for half-stepping or even full stepping mode. But that means you need to adapt the controller side as well...
  4. True, BUT usually you don't get that kind of aluminum. Also, these laptop bodies are treated (anodized, maybe other hardening treatments as well) and hardened after machining. My lasercut aluminum panels are "AlMg3" which is one of the softer, easily machineable alloys. This is worlds apart from 7075 T6 aluminum alloy. "The Ultimaker way" frame panels have one huge advantage: The assembly is idiot proof - you don't have to worry about correct angles, tolerances, warping or anything else when assembling them. Just bolt them together and they will be fine. If you can get to the same result using another technique, please show me I'm currently putting my aluminum extrusion profile frame together. I've been at it for several hours and haven't even completed the profile skeleton yet. You have to carefully tighten one corner at a time, minding all the 90° angles and I didn't even get to the point where the gantry is supposed to fit in there at (nearly) perfect 90° angles...
  5. I've taken a look at the TMC260 stepper driver as well (prototype is coming some time in the distant future...). It's a huge step forwards compared to the allegro / DRV8825 drivers. But in order to get the most out of these drivers, there are lots of changes necessary in the firmware and hardware architecture. For example, the TMC260 needs a serial communication interface to the MCU so that the MCU can program the driver. That's why I didn't bother making a "TMC260 for Marlin boards". The TMC2100 may be different in that aspect, but the TMC260 is the most suitable driver currently available from Trinamic.
  6. OctoPi ist aber kein Arduino mit Marlin (UM2), sondern ein Raspberry Pi mit Linux Betriebssystem. Du vergleichst zwei ziemlich unterschiedliche Systeme miteinander...
  7. Ultimaker nutzt keine eigene Elektronik-Plattform, sondern dieselbe wie "alle" anderen RepRap Drucker. Nur die Platine von Ultimaker ist eine eigene (und eine der besten). Aber die Technik dahinter ist bei allen praktisch dieselbe. Es wird gemunkelt, dass Ultimaker an einer neuen Plattform arbeitet. Sowas ist allerdings nicht Mal eben über Nacht entwickelt und braucht einfach seine Zeit. Ich halte auch absolut nichts von Streaming über USB. Dafür ist die PC Seite einfach viel zu instabil. Willst du einen 50-Stunden Druck vom PC aus streamen? Der PC darf während der ganzen Zeit niemals kurz hängen, oder in den Standby Modus gehen... Schön wäre natürlich, wenn man per USB auf die im Drucker eingelegte SD-Karte zugreifen könnte. Das liesse sich sogar einrichten, aber den Code dazu muss halt einer schreiben.
  8. That... The Ultimaker frame needs a certain minimum wall thickness - regardless to how strong the material actually is at that thickness. It's just necessary to be able to join (and hold) the parts together. Bending (near-)perfect 90° angles is pretty much impossible. You'd never get a satisfactory grade of accuracy. Bending thin steel sheets just for increased strenght works great, but it's a rather expensive process (that you can't do well on your own). And again - thin sheets can't be joined "the Ultimaker way". So, the ideal material would be something that usually comes in thicknesses around 5-10mm. And again - thermal elongation as well as thermal insulation are important factors to consider (aluminum has dire weaknesses in both these aspects). HPL on the other side is the perfect material for the task. Trespa HPL plates for example have all the nice properties. The only problem is getting the stuff cut. Once I'm happy with my prototype, I will clean up the design files and get a quote from a nearby waterjet company. I want waterjet cut HPL frame plates About the composite material: Because you need a thick material, composite would be the best choice when working with metal. But it's a lot of work to join (glue) two thin metal sheets to a plywood panel (6 times). I decided to spare me that work after all, and ordered my prototype with 5mm aluminum sheets now. It's not a good solution imho, but it will make a good, cost-effective and easily done prototype.
  9. That's actually not true! Rounded corners (even very small radii) have a big advantage over sharp corners: The printer can do them without deccelerating. That means much less "ringing" in the object near corners. You can also print details smaller than 0.4mm, especially in the z direction (0.02mm layers are possible). But it doesn't make sense to make a sphere out of 1'000'000'000 polygons. Models with extremely high poly counts usually utilize most of the polygons for heavy smoothing. The printer does some amount of smoothing when printing. In most cases, these high-poly models can have their poly count reduced significantly without any noticeable difference (as long as you don't view them at a very high magnification).
  10. Cura kann das Einfach Cura öffnen, und dann mit "file -> load model file" ein Bild öffnen. Am besten die Bilder vorher in Grautönen abspeichern. /edit: Du kannst das Modell danach auch abspeichern -> "file -> save model" /edit: Übrigens: Das Bild oben kann noch besser aussehen. Wenn du das Bild spiegelst, dann hast du den selben Effekt auf der flachen Rückseite des Objekts (Glasplatte hilft, oder aber nach dem Drucken die Fläche schleifen). Das Bild ist dann normalerweise unsichtbar, ausser wenn man es gegen das Licht hält. /edit: Bei der kleinen Grösse des Objekts und der hohen Auflösung tippe ich darauf, dass dieses Objekt mit einem SLS Drucker gemacht wurde. Bei FDM-Druckern sieht man meistens die Schichten und Linien durch, und die Auflösung ist nicht ganz so gut.
  11. True - Your 3D printer will not benefit from a model that has a microscopically fine mesh resolution. It will be printing with a 0.4mm nozzle and a positioning resolution (not to be mistaken for accuracy!) somewhere in the 0.01mm range. At some point I gave up drawing small circles in Sketchup with more than 24 segments - the printer will smooth it out anyways.
  12. Note that temperatures around 60°C are normal operating temperatures for many electronic components. I mean the component's body temperature when it operates, not the ambient temperature.
  13. Could it be that your thermal barrier heated up too much? I've read something about the Merlin briefly, also got one here, but haven't used it yet. Having a small fan blowing at the PEEK is supposed to help, but not be necessary.
  14. It looks very good already I guess it would take me at least 3 tries to get on par with this print. Plus I'd have to improve my cooling setup first (modded UMO is just not the same as an UM2 ). I also noticed that thinner layers aren't necessarily good for printing quality. Especially any kind of bridging gets better the thicker the layers are. For my technical prints I've recently started to use 0.2mm layer height exclusively. Bridging is almost perfect, it prints a lot faster (even at 30mm/s) because there are less layers to print in total. But your tiny eiffel tower will not look good at 0.2mm layer height - obviously you lose a lot of detail. When printing thin layers, it's essential that you print with the lowest possible nozzle temperature and use 100% cooling fan. Also, printing faster gets better results than printing slow, because you don't want the nozzle to remain in one spot for too long. 3D printing is more than just pressing a button and getting a nice thing out of the printer. You have to observe, understand what's happening, and think about how to improve it for the next time...
  15. I've thought about using steel instead of aluminum (prices are pretty much the same, because aluminum is more difficult to lasercut than steel), but I was concerned about the weight. The Ultimaker frame's stability suffers when you decrease wall thickness (the screws and nuts don't hold that well anymore). And 3mm steel is still about 170% the weight of 5mm aluminum. I'm thinking about making my smaller printer for flexible material from steel. I will change a lot of details about the frame, making it more suitable for thin-sheet material. One idea is making "composite" sheets from two 1mm thin sheets of steel and one 4mm plywood panel sandwiched in between (*). Basically a better Dibond, because both aluminum and PE used in Dibond are balls... There are several waterjet cutting specialists around where I live. Once I'm happy enough with my (large printer) design, I'll have it waterjet-cut from HPL. That would be pretty much the ultimate way to do it. HPL is thermally (and electrically) insulating. It's extremely strong, much stronger than aluminum. It's heavy, but not nearly as heavy as steel. Tensile strength is great, thermal elongation is minimal. It can take temperatures beyond 100°C without problems and usually has a very high quality surface (Trespa is great). When waterjet-cut, you get very smooth and brow-free edges. It's also not as expensive as you'd think. But of course you need to make more than one frame. //edit *: By the way, if you do that "composite" thing, there's one more advantage: You need double the amount of lasered parts, making them much cheaper per-part. Also, 1mm steel is much cheaper and lighter than thicker steel or aluminum. Thinner sheets also come out of the lasercutter very nicely. Plywood is dirt cheap, no need to even mention it Thinking about it, I might even ditch the aluminum frame before even starting, and try the composite way from the start. //edit: I just realised that by making "composite" frame plates I can actually make the frame a lot more beautiful because I can hide most of the ugly cutouts by just not including them in the outer aluminum sheets. That means I am building a composite frame now
  16. That is possible, but usually not desirable. Once the nozzle is heated up, you can't just "stop" extruding for a few seconds. Instead, there will be some material oozing from the nozzle. When the print resumes, that ooze will make it's way onto your printed object. Another side effect from oozing is, that there will be some material "missing" in the nozzle -> underextrusion upon resuming. (*) So, as Didier just mentioned - printing multiple objects instead is better because that way the printer doesn't "pause and resume" but just divides time between multiple printed objects. * With the continuing development of dual-head extruders, these problems might be fixed (more like worked around) soon. But any fix will just mean that the printer has to "do something suitable" with the oozing material. Meaning printing a second object next to the "actual printed object". So, again -> just print two (or more) at once to get the very same effect. // By the way. What's the layer height? (Ignore that. just read it...) You can go as low as 0.02mm for layer height (I've done 0.025 mm prints myself. Sander from the UM team did a 0.02mm print on a UM2 iirc). If you print slowly (30mm/s would be my choice), you can probably lower your printing temperature considerably. For PLA, you could do with temperatures as low as 170 or 180°C (depends a lot on the filament you use). You'll probably have to keep the first layer hot, around 200°C should be enough though. Lowering the first layer height to 0.2mm will help with adhesion. Your tiny object will turn out best at the lowest possible temperature.
  17. POM is great. But afaik you can't lasercut it (I may be wrong here?). But POM is VERY expensive compared to acrylic. Would be easier to use composite materials such as HPL or Dibond. However - these can't be lasercut as well, and they're generally a bit more difficult to process. I found Dibond too weak for my taste. The UM2 seems to do well enough, though. HPL is a better option, but more difficult to machine and slightly more expensive. My next approach will be to have a frame lasercut from 5mm aluminum. Very similar to the UMO in design, but just made of aluminum. It's not an ideal solution imho, but I found that to be the cheapest solution I've evaluated until now. The drawback of aluminum is it's high thermal conductivity. If you want to have your UM enclosed for a heated bed, then you'll either have to insulate the chamber or you'll need much more energy to keep the chamber hot. My idea for the aluminum frame is to make a plywood (or cork) inlay for the chamber. Design isn't finished yet, but it might be in 2-3 weeks.
  18. Acrylic is not the best material for making an Ultimaker frame. It's quite wobbly and warpy. I'd choose the thickest kind of acrylic that you can process on your laser cutter (6-10mm), or prefer good plywood over acrylic. It will also be rather difficult to get a good fit for the ball bearings as acrylic tends to get strong "V" shapes when lasered. Don't forget that the UM2 only uses acrylic for the side panels - which means they're not that much of a weakness because they're supported on all sides by other material (Dibond, which is - tbh - also not the greatest material...). Also, UM's acrylic panels are CNC-milled, not lasered. That's why they get a good fit for their ball bearings. Progress on my UM builds is slow because I have a lot of work to do. But there's a lot going on. I now have all the parts laying around for the second attempt at my "aluminum extrusion profile frame". I've also started to re-think that strategy because it's going a bit too far in the "heavy, difficult to assemble, and expensive" direction.
  19. Presenting the latest prototype of my WARTHOG extruder drive! It's made of lasered stainless steel (3mm for the gears, 2mm for the rest) and printed PLA parts. I used Diamond Age Kiwi Lime PLA, printed at 200°C, 0.2mm layer height and 35mm/s speed. The extruder drive is almost functional, just a few things missing. Once the design is working, I'll publish it on YM.
  20. Very nice! I'll have to give this a try, too... Want to build up a smaller printer for flexible filaments. The red XT part looks very nice - the added weight on the printhead doesn't seem to have much of an impact on print quality.. How's the motor sound at 1/2 microstepping?
  21. I'm not a professional, so this might be wrong: I tighten my belts "as little as possible", but "as much as is needed" to reduce backlash to a minimum - if the belt is not tight enough, you can feel backlash movement when you turn the pulleys back and forth. You don't want to tighten the belts that much as to bend the shafts (which does not take as much as I had thought...). Also, if you pluck the belts (like a guitar), the sound should be similar on all the belts (of the same length). This works better with the long belts. Putting too much force on the motor shaft actually can be a problem. But it takes a really tight belt to put that much force on the motor - definitely too tight then. In that matter, I'm much more concerned when I see the current direct-drive extruders. They put a lot of force on the motor shaft...
  22. It seems like that's the case. My UMO pulley (that has never been used) seems perfectly round. But it's made of "weak", soft aluminum and not a hard alloy like aircraft grade aluminum or something. So if you put a strong force on it through the single setscrew, it may very well warp.
  23. I just took one of the Robotdigg pulleys to the test (milled it into pieces...). It is actually a multipart pulley, BUT not in the traditional way. It consists of 3 parts: the core and two rings. The core is a tube with the shaft bore on the inside and the pulley teeth on the outside. This is one single, CNC machined unit. The two rings are then just what the other multipart pulleys are. But, afaik, the usual multipart pulleys have four parts: A tube, a folded piece that wraps around the tube and forms the teeth, and two rings that hold everything together. These are the "bad" pulleys which are likely to have roundness issues. The robotdigg ones don't have any roundness issues and are very well machined even when inspecting them under a stereo-microscope. ... Actually, I just took apart one of the UMO pulleys - they are made in the very same way as the Robotdigg pulleys (no folded piece for teeth, it's actually solid). Machining quality is worlds apart though. Very ugly under the microscope, and they only have one setscrew. Maybe that second setscrew adds more to the overall "roundness" than I thought.
  24. I look for pulleys that are CNC machined instead of the cheap "assembled from several parts" ones. The latter usually have issues with roundness and may often have sharp brows on the edges. A pulley made on a CNC lathe has the best roundness possible. I also prefer pulleys that have two setscrews instead of just one. Materials? You'll probably find only aluminum pulleys. There are of course different kinds of aluminum alloys - but usually you won't find out which type is used.
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