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Showing content with the highest reputation on 04/20/2019 in all areas

  1. 3 points
    Hello, here is one of my last projects. It`s a mini shredder, made of PLA. We tested the shredder with gummy bears, paper and popcorn. 😉
  2. 1 point
    I just threw all my money at the screen, did any of it arrive? 🙂
  3. 1 point
    I'm printing with one material and removed the other material from the printer. I also set the second material in the Cura software to the same material as the printed material. However, your answer was still helpful, as it made me try to deactivate material 2, which did the trick. I hope this bug will be fixed soon. Thanks!
  4. 1 point
    No shame on you. We do not always have the time to fully explain things. Further, I am working in an educational institution (university), where we are by law required to: "provide education, research and service to the community". Often I also have to provide explanations and guidance to collegues and PhD students about computers, software, and laboratory equipment. So I am used to it, and it fits within my job. Also, I enjoy sharing knowledge, so I don't mind doing this at all. :-)
  5. 1 point
    Don't worry, it is fully on topic because Cloakfiend has asked for help and your answer is really helpful and perfectly explained. So shame on me that I only wrote "you need a resistor" 😞
  6. 1 point
    If you use a 9V battery, and you put the LEDs in series, it will work with the same resistor value, but just give a bit less light. But usually I would prefer to recalculate the resistor: voltage over resistor = battery voltage minus first LED voltage minus second LED voltage. Vr = Vs - Vled1 - Vled2 For an educated guess, that would be: 9V - 2V - 2V = 5V over the resistor (as a crude order of magnitude). Use two identical LEDs. And then calculate the resistor, based on the recommended current through the LED. If it is a high-efficiency LED with low power-consumption, the current could be 1mA. Then the resistor would be: R = Vr / I = 5V / 1mA = 5KOhm If it is a medium efficiency LED, with a current of 5mA, it would be: R = 5V / 5mA = 1KOhm For a LED of 10mA: R = 5V / 10mA = 0.5KOhm = 500 Ohm. This value does not exist, so we take a nearby very common existing value: 470 Ohm, or 510 Ohm. For a very old LED, or a brighter LED that requires a bit more current of 20mA: R = 5V / 20mA = 0.25 KOhm = 250 Ohm. This does not exist, so we would take 240 Ohm or 270 Ohm. For the existing resistor values, Google for: E24 resistor series Among the images in Google, you will then also find the color codes. If you are not familiar with electronics, avoid very high power LEDs like those used in spots or in traffic- or billboard signs. These may get very hot and require special cooling and mounting features. Tiny low power LEDs like in keyboards, stereos, etc..., don't get warm if a correct resistor is used to limit the current to the recommended value. If you want to buy new LEDs, search for low power high efficiency LEDs, because: 10x less current = 10x longer battery life. Search for 1mA or 2mA LEDs, provided they give enough light for your purpose. This may sometimes be very hard to guestimate from the specs, so you may want to try various types. It is a long time ago since I bought LEDs myself, so I can't say what is on the market today. About 20 years ago a typical low power high efficiency LED of 3mm diameter consumed ca. 2mA, but that is 20 years ago... And LED-voltage was 1.65V for red LEDs, 1.9V for yellow, 2.2V for green. Hence my 2V guestimate, which is usually okay for red, orange, yellow, yellowish-green. However, blue, white, and "traffic green" LEDs (=blue chip with phospor on top) usually are around 3...3.5V. But different values exist. Look them up in specs of distributers like RS-components, Farnell, etc... Mr. Google is very helpfull today (credits to the original photographers): However, solder the wires, instead of wrapping. Or try these boards for experimenting: they are very handy, but watch out for short-circuiting wires: With this board you can try lots of different resistor values and LEDs in a short time. I used them a lot. Note: LEDs have virtually no internal current-limiting features: if you apply a too high voltage without external resistor, or if you short-circuit the resistor by accident, the current can get very high and immediately burn out the LED. Don't ask how I know... :-) So, *always* use a separate resistor for current limiting, and never rely on the very unpredictable internal resistance of batteries, power supplies, or LEDs. Further, when plying the leads, use a plier to grip the wire close to the LED, and bend it around the plier, on the side away from the LED. So don't put too much mechanical stress on the plastic housing of the LED. Pulling hard on the leads of tiny 1mm LEDs could cause them to break, since the plastic is not very strong. Here too, don't ask how I know... :-) These are a couple of very good educational Youtube videos on this subject: - https://www.youtube.com/watch?v=Bozb8t6d1Xk - https://www.youtube.com/watch?v=Yo6JI_bzUzo - https://www.youtube.com/watch?v=NfcgA1axPLo - https://www.youtube.com/watch?v=VSpB3HivkhY This reply is a bit longer than I intended, but fortunately I can type very fast. Also, I realise this is a bit off-topic concerning 3D-printing, but I think it is close enough. It may also be usefull for people who want to modify their 3D-printers to mount some indicator LEDs in it. For example you could mount a LED on the bed heater or on the (cold side of) the print head and nozzle, to see when it is on. Carefully calculate resistor-values (Ohms) and power-ratings (Watt).
  7. 1 point
    Actually, nevermind. I opened a file I was sure was made in Inventor 2018 and it opened fine.
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