Homemade Nerf Blasters With 3D Printed Parts

August 27, 2014 by Matt Terndrup 7 Comments

esltcollagesuperawesome

This spectacular bullpup nerf gun was developed by the guys over at Mostly Harmless Arms. It is complete with 3D printed parts in a variety of colors. The Extension Spring/Latex Tubing (ESLT) Blasters were based off of [Kane]’s snapoid trigger design with 1/4″ aluminum for the plunger rods which worked out really well. [Prince Edward] adapted [Kane]’s work and modified it with 3D printing in mind. The original post from 2012 gave an in-depth look into where the idea started.

The documentation for all the printed part files and high quality photos can be found on Nerfhaven. It is really nice to see such a clean design that can be fashioned together on a relatively small budget. This makes these playful nerf blasters easy to duplicate, allowing for a full out office war. Granted, access to a 3D printer is needed, but additive manufacturing devices are getting more and more common these days. Now it’s just a matter of seeing how well they work, which can be deduced from the videos after the break:

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Lost PLA Casting With A Little Help From Your Microwave

August 20, 2014 by Adam Fabio 45 Comments

lost-pla

[Julia and Mason] have been perfecting their microwave-based lost PLA casting technique over at Hackaday.io. As the name implies, lost PLA is similar to lost wax casting techniques. We’ve covered lost PLA before, but it always involved forges. [Julia and Mason] have moved the entire process over to a pair of microwaves.

Building on the work of the FOSScar project, the pair needed a way to burn the PLA out of a mold with a microwave. The trick is to use a susceptor. Susceptors convert the microwave’s RF energy into thermal energy exactly where it is needed. If you’ve ever nuked a hot pocket, the crisping sleeve is lined with susceptor material. After trying several materials, [Julia and Mason] settled on a mixture of silicon carbide, sugar, water, and alcohol for their susceptor.

The actual technique is pretty simple. A part printed in PLA is coated with susceptor. The part is then placed in a mold made of plaster of paris and perlite. The entire mold is cooked in an unmodified household microwave to burn out the PLA.

A second microwave with a top emitter is used to melt down aluminum, which is then poured into the prepared mold. When the metal cools, the mold is broken away to reveal a part ready to be machined.

We think this is a heck of a lot of work for a single part. Sometimes you really need a metal piece, though. Until metal 3D printing becomes cheap enough for everyone to do at home, this will work pretty well.

3D Printed Virtual Reality Goggles

August 9, 2014 by Matt Terndrup 27 Comments

gaming-loop

Oculus, as we know, was acquired by Facebook for $2 billion, and now the VR community has been buzzing about trying to figure out what to do with all this newly accessible technology. And adding to the interest, the 2nd iteration of the development kits were released, causing a resurgence in virtual reality development as computer generated experiences started pouring out from of every corner of the world. But not everyone can afford the $350 USD price tag to purchase one of these devices, bringing out the need for Do-It-Yourself projects like these 3D printed wearable video goggles via Adafruit.

The design of this project is reminiscent of the VR2GO mobile viewer that came out of the MxR Lab (aka the research environment that spun out Palmer Lucky before he created Oculus). However, the hardware here is more robust and utilizes a 5.6″ display and 50mm aspheric lenses instead of a regular smart phone. The HD monitor is held within a 3D printed enclosure along with an Arduino Micro and 9-DOF motion sensor. The outer hood of the case is composed of a combination of PLA and Ninjaflex printing-filament, keeping the fame rigid while the area around the eyes remain flexible and comfortable. The faceplate is secured with a mounting bracket and a pair of aspheric lenses inside split the screen for stereoscopic video. Head straps were added allowing for the device to fit snugly on one’s face.

At the end of the tutorial, the instructions state that once everything is assembled, all that is required afterwards is to plug in a 9V power adapter and an HDMI cable sourcing video from somewhere else. This should get the console up and running; but it would be interesting to see if this design in the future can eliminate the wires and make this into a portable unit. Regardless of which, this project does a fantastic job at showing what it takes to create a homemade virtual reality device. And as you can see from the product list after the break, the price of the project fits under the $350 DK2 amount, helping to save some money while still providing a fun and educational experience.

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Restarting 3D Prints

August 2, 2014 by Eric Evenchick 18 Comments

If a 3D printer is interrupted during a print, it will usually result in a junk part. Resuming the print can be very difficult. A group of researchers at MIT have built an add-on for 3D printers that uses a laser scanner to evaluate the state of the print, and allows the printer to restart.

While this will allow you to salvage some partially competed prints, the interesting application is switching between materials. In the image above, the lower piece was printed in ABS. The print was interrupted to change materials, and the top cube was printed in PLA. This allows for prints to mix materials and colors.

The add-on was tested with the Solidoodle 3D printer, and can be built for about $60. It requires a laser mounted to the print head, and a low-cost webcam for performing the measurements. While the group will not be continuing work on this project, they plan to open source their work so others can continue where they’ve left off.

After the break, we have a video of the printer performing a scan and resuming a print.

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The Radius T-T Velomobile

July 20, 2014 by Eric Evenchick 22 Comments

Over the past year, [Dave] has been hard at work on his human powered vehicle. One year and six hundred hours of build time later, the Radius T-T Velomobile is complete. This 80 lb. vehicle features a custom body, mirrors, and integrated lights.

The Radius T-T started out as a TerraTrike recumbent tricycle. [Dave] built the body by laying up fiber glass on a foam mold. To that he added a variety of 3D printed accessories such as lights and mirrors. Inside the cockpit, the driver can control turn signals and flashers.

[Dave]’s blog provides a massive amount of documentation on the build. Everything from 3D modelling of the vehicle in Blender to the rear view mirror design is discussed. This great looking build should move along quickly with its lightweight design, but we’re still waiting to hear how fast it goes. Either way, it should be a fun mode of transport which will definitely turn some heads.

The Rabbit H1 Is A Stationary Mouse Replacement

July 4, 2014 by Rick Osgood 6 Comments

rabbit h1

[Dave] has some big plans to build himself a 1980’s style computer. Most of the time, large-scale projects can be made easier by breaking them down into their smaller components. [Dave] decided to start his project by designing and constructing a custom controller for his future computer. He calls it the Rabbit H1.

[Dave] was inspired by the HOTAS throttle control system, which is commonly used in aviation. The basic idea behind HOTAS is that the pilot has a bunch of controls built right into the throttle stick. This way, the pilot doesn’t ever have to remove his hand from the throttle. [Dave] took this basic concept and ran with it.

He first designed a simple controller shape in OpenSCAD and printed it out on his 3D printer. He tested it out in his hand and realized that it didn’t feel quite right. The second try was more narrow at the top, resulting in a triangular shape. [Dave] then found the most comfortable position for his fingers and marked the piece with a marker. Finally, he measured out all of the markings and transferred them into OpenSCAD to perfect his design.

[Dave] had some fun with OpenSCAD, designing various hinges and plywood inlays for all of the buttons. Lucky for [Dave], both the 3D printer software as well as the CNC router software accept STL files. This meant that he was able to design both parts together in one program and use the output for both machines.

With the physical controller out of the way, it was time to work on the electronics. [Dave] bought a couple of joysticks from Adafruit, as well as a couple of push buttons. One of the joysticks controls the mouse cursor. The other joystick controls scrolling vertically and horizontally, and includes a push button for left-click. The two buttons are used for middle and right-click. All of these inputs are read by a Teensy Arduino. The Teensy is compact and easily capable of emulating a USB mouse, which makes it perfect for this job.

[Dave] has published his designs on Thingiverse if you would like to try to build one of these yourself.

Heating Up A Printrbot’s Bed

June 16, 2014 by Eric Evenchick 32 Comments

Heated beds for 3D printers help reduce the amount of curling and warping of parts. The warping happens when the part cools and contracts. The heated bed keeps the part warm for the entire print and reduces the warping.

As an upgrade to her Printrbot, [Erin] added a heated bed. The first plan was to DIY one using Nichrome wire, but heated beds are available at low cost. They’re basically just a PCB with a long trace that acts as a resistor. She added a thermistor to monitor temperature and allow for accurate control.

The Printrbot heated bed worked, but didn’t heat up quite quick enough. [Erin] was quick to scratch off the solder mask and solder new leads onto the board. This converted the board into two parallel resistors, halving the resistance and doubling the power.

This version heated up very quickly, but didn’t have a steady heat. The simple control that was being used was insufficient, and a PID controller was needed. This type of control loop helps deal with problems such as oscillations.

The Printrbot’s firmware is based on Marlin, which has PID support disabled by default. After rebuilding the code and flashing, the PID gains could be adjusted using g-codes. With the values tuned, [Erin]’s printer was holding steady heat, and can now print ABS and PLA with minimal warping.