Nanoscale 3D Printing

March 14, 2012 by Brian Benchoff 17 Comments

This 3D-printed model of the Tower Bridge is only 200 micrometers long. To put that into perspective, the distance between the towers is the width of a human hair. This model is the product of research at the additive manufacturing department of the Vienna University of Technology

The models were fabricated much like normal stereolithography – a laser shines onto a vat of light-sensitive resin. The resin hardens when exposed to light, and the model is built up layer by layer. These nanoscale models were made using a process called “two-photon lithography,” something we’re not going to pretend we understand completely but here’s a nice paper that provides a good overview. Needless to say, the precision these prints exhibit are nearly ludicrous. The researchers claim a precision of ±1µm, a respectable amount of precision for very high-tech machining applications.

The researches posted a video of the fabrication of a nanoscale F1 race car filmed in real-time. Check that out after the break.

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Carabiner Helps You Hone Your Milling Skills

March 13, 2012 by Mike Szczys 26 Comments

[Christian] is learning to use the metal milling tools at what we assume is his local Hackerspace. We love this about the communal spaces, they provide so many opportunities to delve into new fields. He embarked on a voyage that included visits to most of the machinery in the shop as he build his own carabiner with a magnetic gate. He’s not going to be hanging off the side of a mountain from it. But his keys or a water bottle will find a happy home thanks to the device.

It all started with some sketches to establish the shape of the overall design. From there he spent some time modelling the frame of the carabiner in CAD. He’s lucky enough to have access to a water jet which took the SolidWorks files and cut out the aluminum frame for him. That left a part with very sharp edges, so he used a wood router with a carbide bit to round them over.

The next part is adding the gate. He used an end-mill to add a mounting area on the frame. The locking ring for the gate was textured using a knurling tool, and the rest is milled with a simple cutting tool. This gate uses a magnet to center itself, with the knurled ring as the only mechanical latching mechanism. [Christian] does a good job of demonstrating the completed carabiner in the clip after the break.

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3D Printing From An Android Device

March 10, 2012 by Brian Benchoff 5 Comments

[skullkey] over at the House4Hack hackerspace in Pretoria, South Africa wanted a way to get kids excited about technology and desktop fabrication labs. Wanting to give kids a visceral feel for the march of technology, he created Makerdroid, an android app that allows for the creation 3D objects on an Android tablet and preparing them to be printed on a Reprap or Makerbot.

What’s really interesting about this build is not only the fact that [skullkey] and his lovely beta testers are generating .STL files on an Android device, the object files are also being converted to GCode on the Android, without the need for a conventional computer. Makerdroid uses the very popular Skeinforge to generate the instructions for the printer (although a lot of people are switching over to Slic3r).

Makerdroid doesn’t need a PC to print objects out on a 3D printer, but we think the process of shuffling GCode files from a tablet to the printer with an SD card is a little archaic. It might be possible to print directly from an Android tablet over Bluetooth with the Android Bluetooth Reprap app that is currently in development. Still, we love the idea of printing objects we just created on a touch screen, as shown in the Makerdroid demo video after the break.

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Building A Magnetic Rotary Encoder

March 8, 2012 by Mike Szczys 15 Comments

[Long Haired Hacker] has undertaken a high-resolution 3D printer build. He got his hands on some motors to drive the build platform but it doesn’t have a built-in encoder. He knows that optical encoder wheels can have problems due to dirt and grim as well as ambient light so he set out to find a better way of providing feedback to the controller. He ended up building his own magnetic rotary encoder which is shown above.

At the heart of the system is an AS5043 magnetic rotary sensor. The chip, which runs from $6.50-$11, can detect and report the rotation of a magnetic field with great precision. The rotation data can be read out in degrees using SPI, but it sounds like there’s also grey code output on a few pins if that suits your needs a bit better. The magnet which the chip measures is mounted in a sleeve milled to seat inside of a bearing ring.

The 3D printing method [Long Haired Hacker] has chosen uses a projector and light-cured resin to achieve the kind of results seen in this other hi-res printer.

New Extruder 3D Prints Tasty Treats Using Chocolate

February 29, 2012 by Mike Szczys 18 Comments

If you’ve never felt at home with a piping bag in your hands this chocolate extruder will come to your rescue. It can replace the plastic extruder head on your 3D printer (RepRap, Makerbot, most 3-axis CNC machines, etc.), letting you turn your digital creations into decadent reality.

The head uses a progressive cavity pump to feed the chocolate from a reservoir through the printing nozzle. It’s important to keep the chocolate warm or it will set up so when [Tomi Salo] designed the print head he included a heat shroud through which warm air can be circulated. He uses a shoe dryer to source the hot hair which is patched into the heat shroud with a length of tubing.

This extruder can be 3D printed but be careful what material you use. [Tomi] mentions that PLA is ‘sort of food-safe’ but ABS is not. We wonder if the design could be altered for milling out of aluminum or stainless? At any rate, if you’re going to give it a try you might find [Tomi’s] advice on working with chocolate useful.

[via @clothbot]

Light Painting With A String Plotter

February 27, 2012 by Mike Szczys 12 Comments

[Matt Bell] sends a shout-out to Hackaday by creating a light-painting of our logo with his string plotter. He starts off by setting up a pair of stepper motors which each have a spool to wind and unwind a string. The plotter is made by suspending a stylus between these two strings. In this case, he’s using a wireless LED board (seen above) built from the remote control receiver/transmitter from a toy car. The link above is part of a Flickr set from which you can get the whole story by reading the captions of each image.

After the break we’ve embedded a clip of an in-progress light painting. You can see there’s some oscillation of the LED unit that makes it a bit less precise than the CNC light painter we saw a couple of weeks ago. It seems like string plotters usually don’t have this issue if the stylus has something to help stabilize it. We wonder if a piece of acrylic would help get rid of the shakes? Continue reading “Light Painting With A String Plotter” →

3D Printed Lugs For Your Custom Bike

February 24, 2012 by Mike Szczys 39 Comments

We haven’t heard much about 3D printing using stainless steel as the medium, but that’s exactly what’s going on with the lugs used to assemble this bicycle frame. They’re manufactured using LaserCusing, which is a brand name for parts produced using Selective Laser Melting. The video after the break gives you an overview of what it takes to clean up each of these parts.

The laser melts metal power to solidify areas needed in the final part. Just like the hobby printing we’ve seen on the RepRap or Makerbot there are structural supports necessary to complete the print job, and these need to be removed after the laser has done its work. This is where the majority of the labor comes in. You’ll see a ton of waste material pulled out of the cage-like lug, and we’re sure there’s no shortage of filing and polishing to finish up. But wow, what an interesting result. We just need to figure out if anyone has found a cost-effective way to hack together one of these metal-powder printers.

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