You’d be hard-pressed to find more ardent supporters of 3D printing then we here at Hackaday; the sound of NEMA 17 steppers pushing an i3 through its motions sounds like a choir of angels to our ears. But we have to admit that the hard plastic components produced by desktop 3D printers aren’t ideal for a number of applications. For example, the slick plastic is useless for all but the most rudimentary of wheels. Sure there are flexible filaments that can give a printed wheel a bit of grip, but they came with their own set of problems (not to mention, cost).
In the video after the break, [Design/Forge] demonstrates a clever method for fitting polyurethane rubber “tires” onto 3D printed hubs which is sure to be of interest to anyone who’s in the market for high quality bespoke wheels for their project. The final result looks extremely professional, and while there’s a considerable amount of preparation that goes into it, once you’re set up you should be able to pump these out quickly and cheaply.
The process begins with a 3D printed mold pattern, which includes the final tire tread texture. This means you can create tire treads of any design you wish, which should have some creative as well as practical applications. The printed part is then submerged in silicone rubber and allowed to cure for 8 hours. Once solidified, the silicone rubber becomes the mold used for the next steps, and the original printed part is no longer needed.
The second half of the process is 3D printing the wheels to which the tires will be attached. These will be much smaller than the original 3D printed component, and fit inside of the silicone mold. The outside diameter of the printed wheel is slightly smaller than the inside diameter of the mold, which gives [Design/Forge] the space to pour in the pigmented polyurethane rubber. The attentive viewer will note that the 3D printed wheel has a slight ribbed texture designed into it, so that there will be more surface area for the polyurethane to adhere to. Once removed from the mold and cleaned up a bit, the final product really does look fantastic; and reminds us of a giant scale LEGO wheel.
Whether you’re casting metal parts or just want a pair of truly custom earbuds, creating silicone molds from 3D printed parts is an extremely useful skill to familiarize yourself with. Though even if you don’t have a 3D printer, there’s something to be said for knowing how to mold and cast real-world objects as well.
Continue reading “3D Printed Wheels Get Some Much Needed Grip”
This collaboration between ETH and the Disney empire’s research arm is a ultra-light robot that can roll across horizontal surfaces and also transition and climb walls.
The robot has four wheels with one steerable set, but its secret sauce is the two propellers gimbaled on its back. Using these propellers it can move itself across the ground, but also, when approaching a wall, provide enough thrust to overcome the gravity vector.
Naturally, the lighter the robot, the less force will be needed to keep it on the wall. That’s why the frame is made from carbon fiber corrugated sandwich panels. The motors, batteries, and controllers are all also light and small.
We liked how the robot was, apparently, using its propellers to provide additional stability even while on the ground. There is a video after the break, and more information can also be found on the Disney Research webpage.
Continue reading “VertiGo Robot Drives Up Walls”
The team over at [Braille Skateboarding] is willing to ride just about anything. This week they’re testing out 3D printed skateboard wheels. We’re not just talking rolling around here, the [Braille] team takes their experiments out to the skate park and gives them to the locals to test out. Tail whips, jumps, ollies, and grinds were on the agenda. The skaters were a bit apprehensive, as this is the third time they’ve tested 3D printed wheels.
The first set shattered upon landing a jump. That set appears to have been made from PLA with about 10% infill. The second set were made from NinjaFlex, which had no shattering problems, but was so squishy that the wheels simply flattened under the weight of the riders. The third set, printed by [Nick Lindenmuth] work great. They have a bit of give, but don’t shatter. We’re guessing this set is either ABS or one of the more exotic filaments. It’s pretty amazing that 3D printers are capable of spitting out wheels that not only handle the load of rider, but the shock load of coming down from jumps and tricks.
Check out the video after the break. If you want to see more skateboard projects, check out this skateboarding themed Hacklet!
Continue reading “Skateboard Hackers Trick on 3D Printed Wheels”
Mini Sumo seems like one of those hobbies that starts out innocently enough, and ends up with a special room in the house dedicated to it. One day you’re excitedly opening up your first Basic Stamp kit, and the next you’re milling out mini molds on a mini lathe to make mini extra sticky tires.
[Dave] started out trying to find a part from the local big box store that was just a little bigger than the wheel he wanted to rubberize. He set the wheel inside a plumbing cap and poured the urethane in. It worked, but it required a lot of time with a sharp knife to carve away the excess rubber.
In the meantime he acquired a Sherline Mini Mill and Lathe. With the new tools available to him, he made a new mold out of a bit of purple UHMW and some acrylic. This one produced much nicer results. Using a syringe he squeezed resin into the mold through a hole in the acrylic. Much less cleanup was needed.
He later applied these methods to smaller, wider wheels as his mini sumo addiction took a stronger hold on his life.
Skateboards are fun, but you have to do all that pesky kicking in order to get anywhere. That’s why [Nick] decided to build his own electric skateboard. Not only is the skateboard powered with an electric motor, but the whole thing can be controlled from a smart phone.
[Nick] started out with a long board deck that he had made years ago. After cleaning it up and re-finishing it, the board was ready for some wheels. [Nick] used a kit he found online that came with the trucks, wheels, and a belt. The trucks have a motor mount welded in place already. [Nick] used a Turnigy SK3 192KV electric motor to drive the wheels. He also used a Turnigy electronic speed controller to make sure he could vary the speed of the board while riding.
Next [Nick] needed some interface between a smart phone and the motor controller. He chose to use an Arduino Nano hooked up to a Bluetooth module. The Nano was able to directly drive the motor controller, and the Bluetooth module made it easy to sync up to a mobile phone. The Android app was written using MIT’s App Inventor software. It allows for basic control over the motor speed so you can cruise in style. Check out the video below for a slide show and some demonstration clips.
It’s a popular project, and eerily similar to the one we saw a couple months back.
Continue reading “On Your Phone While Driving an Electric Skateboard”
[Sugapes] always wanted to cut a few corners and build a really, really cheap 3D printer, but the idea of using linear actuators – pricing them, sourcing them, and the inevitable problems associated with them – scared him away. One day, he realized that moving in a plane in the X and Y dimensions wasn’t hard at all; cars and robots do this every day. Instead of moving a 3D printer bed around with rods and pulleys, [Sugapes] is moving his 3D printer around with wheels. It’s different, it’s interesting, and it’s the perfect project to show of his creativity for The Hackaday Prize.
The drive system [Sugapes] is using is called a holonomic drive system. In his build, three omnidirectional wheels are attached to continuous rotation servos, each of them mounted 120 degrees apart. The print bed is simply placed on these wheels, and with the right control algorithms, [Sugapes] can move the bed in the X and Y axes. With an extruder on a Z axis above the bed, this setup becomes a 3D printer with a theoretically unlimited XY build axis. Pretty clever, huh?
There are a few problems [Sugapes] will have to overcome to turn this project into a proper printer. The omnidirectional wheels aren’t the best at transferring movement to the bed, so a quartet of USB optical computer mice are being used for a closed loop system. [Sugapes] put up a video of his project, you can check that out below.
The project featured in this post is an entry in The Hackaday Prize. Build something awesome and win a trip to space or hundreds of other prizes.
Continue reading “THP Entry: A Holonomic Drive 3D Printer”
Of all the free parts up for grabs at a friend’s house, nobody wanted the scrap wheelchair wheels: including [Eric]. That is, of course, until he spontaneously decided to try something a bit crazy and take on a bizarre yet remarkably imaginative hubless wheel bike build.
After attaching the wheelchair’s rim and its affixed handrail to the rim on his bike, [Eric] mounted pairs of rollerblade wheels to a separate piece of metal that essentially act as bearings. As the build progresses, the bike is further refined. More rollerblade wheels, a giant sprocket, and a pile of machined aluminum pieces. The valve stem for the tire had to be relocated to allow the wheel to spin freely.
The finished product is a stunning bicycle, which [Eric] later revisited, updating the rollerblade wheels to precision-lathed plastic (specifically UHMWPE) rollers. Make sure you watch the video of the Hubless Horseman in action. If, for some reason, your only prior exposure to hubless wheels is the TRON light cycle or [Kirk’s] motorcycle from the Star Trek reboot, do yourself a favor and check out their inventor, Franco Sbarro.