Pen Plotter From PCB Panels

January 21, 2022 by Chris Lott 6 Comments

Hacker [12344321A] has built a clever open-source pen plotter having a frame made from odd-shaped PCB panels (Chinese). It holds an ordinary drafting pen and draws on a small writing platform 8 x 8 cm square. This is barely enough space to draw a business card, depending on which country you’re from. The motion appears to be provided by DVD stepper motor head positioning assemblies, and the controller is an ESP32-based GRBL 3-axis board. User control is via WiFi and the plotter can be seen in operation being driven from the user’s smartphone (see video on the project page above).

Linear Motion Assemblies from a DVD player?

This looks like it would be an inexpensive build, and seems sturdy enough despite being literally held together by solder and paper clips. But be forewarned, the project is documented on an open-source hardware sharing site sponsored by EasyEDA called OSHWHub — the Chinese equivalent of their similar English-language OSHWLab. Hence all the notes are in Chinese, although Google translate can help here. [12344321A] provides all the engineering design files under GPL 3.0 license.

Thanks to [J. Peterson] for finding this project and bringing it to our attention via the tip line.

3D Printing Copper

January 20, 2022 by Al Williams 28 Comments

People really want to 3D print metal, but while true metal printers exist, they still are expensive and out of reach of most hackers. However, even if you can afford an exotic printer or use metal-impregnated polymer, you don’t often see copper as a print material. Copper has high electrical and thermal conductivity which makes it very useful. But that thermal conductivity also makes it very difficult to print using any process that involves heating up the material and copper reflects common lasers used in the 3D printing process. However, a German company, Infinite Flex, is claiming a breakthrough that will allow printers that use a standard IR laser to produce copper parts. The material, Infinite Powder CU 01 is suitable for selective laser sintering and several other laser-based techniques.

The powder has 99.5% copper and particle sizes of between 10 and 45 microns. There are some copper alloys that reduce thermal conductivity to allow printing, but often the reason you want a copper part is for its thermal properties. A kilogram of the powder will set you back nearly $100, so it isn’t dirt cheap, but it isn’t astronomical, either.

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Monowheel Mayhem: When Good Gyroscopic Precession Goes Bad

January 19, 2022 by Ryan Flowers 11 Comments

Since the dawn of the age of the automobile, motorheads have been obsessed with using as few wheels as possible. Not satisfied with the prospect of being incompletely maimed by a motorcycle, the monocycle was born. Gracing the covers of Popular magazines and other periodicals, these futuristic wheels of doom have transfixed hackers of all kinds. [James Bruton] is one such hacker, and in the video below the break you can see his second iteration of a 3d printed monowheel.

[James]’ wonderful monowheel is beautifully engineered. Bearing surfaces, gears, idlers, motors, and yes, twin gyroscopes are all contained within the circumference of the tire. The gyroscopes are actuated by a rather large servo, and are tied together by a gear that keeps their positions in sync. Their job is to keep the monowheel balanced at all times.

But as [James] discovered, the chief difficulty of only having one wheel isn’t lateral balancing. Ask any monocyclist and they’ll assure you that it’s possible. The real trick is balancing the machine fore and aft. Unlike a two wheeled velocipede, the monowheel has nothing to exert torque against save for a bit of gravity.

As [James] found out the hard way, it was within this fore-aft balancing act that the gyroscopic precession reared its ugly head. The concept is explained well in the video. We won’t spoil the surprise ending because the explanation and conclusion are quite good so make sure to watch to the end!

If you’d like to look at [James]’ first version, we covered it here. And if you’re the daredevil type, perhaps we can interest in you in a two stroke human sized monowheel that will probably end in an ER visit. At least they wore a helmet. Thanks to [Baldpower] for the tip!

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Extreme Thermal Mods For 3D Printing Exotic Materials

January 19, 2022 by Dan Maloney 15 Comments

For general everyday use, there’s nothing wrong with the standard selection of plastics that most 3D printer filaments are available in. PLA, ABS, PETG — they’ve all got their place, and they’re all pretty easy to work with. But if you need to work with more exotic materials, you might need to go to extremes and modify an off-the-shelf printer for high-temperature work.

For the team led by [Andreas Hagerup Birkelid] at the Norwegian University of Science and Technology, the standard menu of printer chow wasn’t up to the jobs they had in mind. They wanted to print using polyether ether ketone, or PEEK, a high-performance thermoplastic with useful mechanical and thermal properties, in addition to chemical resistance. Trouble is, the melting point of PEEK is a whopping 343°C (649°F), making it necessary to turn up the heat — a lot. A standard Creality CR-10 printer was upgraded to withstand not only the 500°C max temperature of the new hot end and 200° printed bed, but also to survive operating in what amounts to an oven — a balmy 135° in a chamber made from IKEA cabinets. That entailed replacing plastic parts with metal ones, upgrading belts, pulleys, and wires, and moving all the electronics outside the enclosure. Even the steppers got special treatment, with water cooling to keep their magnets from reaching the Curie point.

The mods seemed to do the trick, because a Benchy printed in a carbon-fiber PEEK filament came out pretty good. It seems like a long way to go and kind of pricey — $1,700 for the printer and all the mods — but if you have a need to print exotic materials, it’s way cheaper than a commercial high-temp printer.

[via 3D Printing Industry]

Giant 3D Prints Piece-by-Piece

January 16, 2022 by Al Williams 18 Comments

While FDM printers have gotten bigger lately, there’s almost always going to be a part that is bigger than your bed. The answer? Break your design into parts and assemble them after printing. However, the exact method to do this is a bit of a personal choice. A mechanical engineering student wrote:

After researching the state of the art as well as your ideas here on reddit, I realized, that there are almost no universal approaches to divide a large part and join the pieces which maintain mechanical strength, precisely position each segment, and also counteract tolerances due to the FDM-process.

Therefore I tried to develop a universal method to segment large trim parts, additively manufacture each segment and finally join those segments to form the desired overall part.

The result is a research paper you can download for free. The method focuses on thin parts intended as automotive trim, but could probably be applied to other cases.

You can read about the thought process, but the final result was a joggle — a joint made with a rabbet and tongue. Adhesive holds it together, but the joint offers advantages in constraining the final product and the transmission of force in the assembly. Judging by the picture, the process works well. It would be interesting to see slicer software develop the capability to segment a large model using this or a similar technique.

Of course, you can just build a bigger printer, at least to a point. It seems, though, that that point is pretty big.

Recycling Soda Bottles Into Filament To Print Smaller Soda Bottles

January 15, 2022 by Lewin Day 34 Comments

Thermoplastics are great, because you can melt them down and reform them into whatever you like. This is ably demonstrated by [The Q] by recycling old soda bottles into usable 3D printer filament.

Cute, huh? Why aren’t Coca-Cola making these? Tiny fake grocery items already proved hugely popular in Australia.

Soda bottles are usually made out of PET plastic, or polyethylene terephthalate, which is one of the most popular thermoplastics in modern society. A soda bottle can be cut into a continuous long, thin strip with the use of a simple hand-operated machine that slices the bottle with a blade. This strip of plastic can then be fed through a heated nozzle in order to produce filament for 3D printing. [The Q] demonstrates both parts of this process, including using a motorized reel to take up filament as the bottle material is fed through the extruder.

The filament is then demonstrated by printing tiny versions of soda bottles. [The Q] fills these with soda and gives them the appropriate lids and labels for completion’s sake. It’s a neat way to demonstrate that the filament actually works for 3D printing. It bears noting that such prints are almost certainly not food safe, but it’s really a proof of concept rather than an attempt to make a usable beverage container.

Like similar builds we’ve seen in the past, the filament is of limited length due to the amount of plastic in a single bottle. We’d like to see a method for feeding multiple bottles worth of plastic into the extruder to make a longer length spool, as joining lengths of filament itself can be fraught with issues. Video after the break.

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Improve Your Front Panels

January 15, 2022 by Al Williams 58 Comments

For many of us, the bane of electronic projects is making a professional-looking enclosure. Sure, 3D printing has made it easier to make the actual enclosure, but there’s still the problem of labeling it. [Richard Langner] has the answer with something he calls easy front panels. You can read about it or watch the tutorial video below.

The concept is easy enough. You create your beautiful artwork in your choice of graphics programs. The example uses Inkscape, but you could do it in anything, even PowerPoint. You print it out and cut it to size. You could, of course, print it in color or — as the example does — color it in by hand.

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