[MechEngineerMike]’s bike boost is just a pleasure to look at, and, we’re certain, a relief to use. While it’s not going to rocket you down the street, it will certainly take some of the pain away. (Just like the professionals!)
It’s one thing to design a device that can fit one bicycle. It’s quite another feat if it can support multiple frames. On top of that, it’s even simple. It attaches at one point and transfers the power to the wheel easily. There’s even just one wire to connect, an RCA cable, to engage the boost.
We really like the clever way [Mike] used the rotating shell of an outrunner motor as the surface that presses against the wheel. We wonder if a cast polyurethane rubber tire for the motor would help, or just help overheat the motor?
The parts for the device are 3D printed and pretty chunky. They should hold up. Check out the video of it boosting [Mike] to the grocery store, where he can, presumably, buy less with all the calories he saved after the break.
Continue reading “Boost Around Town with This 3D Printed Bicycle Assist”
What do you print with your 3D printer? Key chains? More printer parts (our favorite)? Enclosures for PC boards? At Johns Hopkins, they want to print bones. Not Halloween skeletons, either. Actual bones for use in bodies.
According to Johns Hopkins, over 200,000 people a year need head or face bone replacements due to birth defects, trauma, or surgery. Traditionally, surgeons cut part of your leg bone that doesn’t bear much weight out and shape it to meet the patient’s need. However, this has a few problems. The cut in the leg isn’t pleasant. In addition, it is difficult to create subtle curved shapes for a face out of a relatively straight leg bone.
This is an obvious application for 3D printing if you could find a suitable material to produce faux bones. The FDA allows polycaprolactate (PCL) plastic for other clinical uses and it is attractive because it has a relatively low melting point. That’s important because mixing in biological additives is difficult to do at high temperatures.
Continue reading “3D Printing Bone”
People like music, but they are also visual creatures. Perhaps that’s why music visualization is such a common project. Usually, you think of music visualization as using LEDs or a computer screen. However, [Gieeel] did his music visualization using a 3D printer.
Sure, the visualization is a little static compared to LEDs, but it does make an interesting conversation piece. The actual process isn’t very difficult, once you have the idea. [Gieeel] captured the waveform in Audacity, did a screen capture, and then converts the image to an SVG file using Inkscape.
From there, you can use many different CAD tools to convert the image into a 3D object. [Gieeel] used Autodesk Fusion 360 and had the resulting object professionally 3D printed.
We’ve seen other kinds of sound sculptures before. Of course, we’ve also seen a lot of traditional visualizations, as well.
The usual go-to when building a simple robot arm is the ever-pervasive hobby servo. However, these devices are not precise, and are typically jerky and unreliable. They have their advantages, but if strength is not needed a stepper motor would provide much better motion in the same price range.
Those are the lines along which [Bajdi] was thinking when he forked the Mearm project, and adapted it for small stepper motors. First he tried printing out the servo version on thingiverse. It worked, but the parts were not ideal for 3D printing, and he didn’t like the movement.
So he purchased some 28BYJ-48 motors. These are tiny little geared steppers that tend to show up in the odd project. He modified and simplified the files in FreeCAD. With the addition of a CNC shield and an Arduino he had every thing he needed for the upgrade. A servo is now only used for the gripper.
The robot is almost certainly weaker in its payload ability, but as you can see in the before and after videos after the break, it is dramatically smoother and more accurate.
Continue reading “Simple Robot Arm With Steppers Has Pleasingly Smooth Motion”
A Japanese lab is investing some time in the possibilities of a 5-axis 3D printer. They show it printing using five axis as well as doing finish machining on a printed part. We’ve covered parts of why this is the right direction to go for 3D printing in another post.
It looks like they have modified an existing industrial machining center for use with a 3D printing nozzle. This feels like cheating, but it’s the right way to go if you want to start playing with the code early. The machines are intensely accurate and precise. After all, building a five axis machine is a well known science, 3D printing with one opens a whole new field of research.
There isn’t too much to show in the video, other than it’s possible and people are doing it. The Five-axis 3D printing and machining is uninteresting, we have been able to machine plastic for a long time.
However, they show one blue part in which the central axis of the part was printed vertically, but revolute splines along its outer perimeter were printed normal to the surface of the already printed 3D part. Which is certainly not commonly done. Video after the break.
Continue reading “Japanese Lab Builds 5-Axis 3D Printer”
Only about 10% of blind people around the world can read Braille. One primary reason is the high cost of Braille displays. The cost is a result of their complexity and reliability – required to ensure that they are able to handle wear and tear.
[Vijay] has been working since 3 years on a Refreshable Braille Display but has only recently been able to make some substantial progress after teaming up with [Paul D’souza]. During his initial experiments, he used dot matrix printer heads, but the current version uses tiny vibration motors as used in mobile phones. He’s converting rotary motion of the tiny motors in to linear movement for pushing the Braille “cell” pins up and down. The eccentric weight on the vibration motor is replaced with a shaped cam. Continuous rotation of the cam is limited by a stopper, which is part of the 3D printed housing that holds the motors. Another 3D printed part has three cam followers, levers, springs and Braille pins rolled in one piece, to create half a Braille cell. Depending on the cam position, the pins are either pushed up or down. One Braille cell module consists of two cam follower pieces, a housing for six vibration motors, and a cover plate. Multiple modules are chained together to form the display.
The next step would be to work on the electronics – in particular ensuring that he is able to control the motor movement in both directions in a controlled manner. Chime in with your comments if you have any ideas. The 3D design files are available from his Dropbox folder.
Continue reading “Refreshable Braille Display and Braille Keyboard”
MakerBot is not dead, but it is connected to life support waiting for a merciful soul to pull the plug.
This week, MakerBot announced it would lay off its entire manufacturing force, outsourcing the manufacturing of all MakerBot printers to China. A few weeks ago, Stratasys, MakerBot’s parent company, released their 2015 financial reports, noting MakerBot sales revenues have fallen precipitously. The MakerBot brand is now worth far less than the $400 Million Stratasys spent to acquire it. MakerBot is a dead company walking, and it is very doubtful MakerBot will ever be held in the same regard as the heady days of 2010.
How did this happen? The most common explanation of MakerBot’s fall from grace is that Stratasys gutted the engineering and goodwill of the company after acquiring it. While it is true MakerBot saw its biggest problems after the acquisition from Stratasys, the problems started much earlier.
Continue reading “The MakerBot Obituary”