The build relies on [Ivan]’s giant 3D-printed Lego-like assembly kit. It lets him simply bolt together a bunch of plastic girders to make the key parts of the excavator, including the base and the digger arm itself. The digger arm is controlled with linear actuators of [Ivan’s] own design, which uses servos and threaded rod to do the job. They’re not as cool as hydraulics or pneumatics, but they get the job done well. For propulsion, [Ivan] built a tracked drive system again using his unique Lego-like blocks. The tracks were tedious to assemble, but add a lot to the excavators Awesomeness Quotient (AQ).
The overall build is quite slow, and more than a little fragile. It’s not quite ready for hardcore digging tasks. In reality, it’s serving as a test bed for [Ivan]’s 3D-printed building blocks that get better every time we see them. Video after the break.
Some projects start with a relatively simple idea that quickly turns into a bit of a nightmare when you get to the actual implementation. [Hacksmith Industries] found this to be the case when they decided to build a giant rideable hexapod, Megahex. [YouTube]
After seeing a video of a small excavator that could move itself small distances with its bucket, the team thought they could simply weld six of them together and hook them to a controller. What started as a three month project quickly spiraled into a year and a half of incremental improvements that gave them just enough hope to keep going forward. Given how many parts had to be swapped out before they got the mech walking, one might be tempted to call this Theseus’ Hexapod.
Despite all the issues getting to the final product, the Megahex is an impressive build. Forward motion and rotation on something with legs this massive is a truly impressive feat. Does the machine last long in this workable, epic state? Spoilers: no. But, the crew learned a lot and sometimes that’s still a good outcome from a project.
If you’re looking for more hexapod fun, checkout Stompy, another rideable hexapod, or Megapod, a significantly smaller 3D-printed machine.
We’ve got to be honest, we’ve been keeping an eye on the progress [Vang Hà] has been making on this build for a few weeks now. The first video below is a full tour of the finished project, which is painstakingly faithful to the original, a Caterpiller 390F tracked excavator. As impressive as that is, though, you’ve got to check out the build process that starts with fabricating the tracks in the second video below. The raw material for most of the model is plain gray PVC pipe, which is sliced and diced into flat sheets, cut into tiny pieces using a jury-rigged table saw, and heat formed to create curved pieces. Check out the full playlist for a bounty of fabrication delights, like tiny hinges and working latches.
We can’t possibly heap enough praise onto [Vang Hà] for his craftsmanship, but that’s not all we love about this one. There are tons of helpful tips here, and plenty of food for thought for more practical builds. We’re thinking about that full set of working hydraulic cylinders that operates the boom, the dipper, and the bucket, as well as the servo-operated hydraulic control valves. All of it is made from scratch, of course, and mostly from PVC. Keep that in mind for a project where electric motors or linear actuators just won’t fill the bill.
To be fair, the rules of the game have changed lately. Time was when a nipper would ask for the impossible, and we dads would never have to deliver. But with CNC routers, 3D-printing, and industrial-grade CAD software you can use for free, the possibility hurdle is getting ever shorter. Still, when his son put in this request, [Alex Lovegrove] really delivered. Everything on this excavator works, from tracks to boom to bucket. There are hundreds of parts, mostly machined from plywood but with a smattering of 3D-printed gears and brackets. The tracks and slew gear are powered by gear motors, while linear actuators stand in for hydraulic rams on the boom. The videos below show the machine under test and the unbearable cuteness of it being loved.
When making a toy excavator arm, or any robotic arm, the typical approach is to put motors at the joints, or if there isn’t room, to put the motors somewhere else and transfer the force using fishing line and pulleys. [Navin Khambhala] chose instead to do it more like the real excavators, with hydraulics using syringes. And we have to admit, the result it pretty elegant in its simplicity.
The syringes do the job of single-acting hydraulic actuators, one at the motor and the other where the force is needed. In between them, what appears to be clear vinyl tubes carry the fluid between syringes. 12 volt DC motors with bolts on them move nuts attached to the syringe pistons to push and pull the pistons. It is so simple that no further explanation is needed, though like most apparently simple things, we’re sure a lot of effort went into making it that way. The video below shows the finished product, as well as walks through the making of it.
[Frank] was lucky enough to score a bucket wheel excavator LEGO set as a birthday present, and we won’t lie – we’re jealous. However, out of the box, the kit is somewhat limited; there is only one motor to animate the entire machine and it can’t be fully remote controlled. But don’t worry — [Frank] set out to change that (Google Translation).
The first part of the build was to add motors to control the different functions of the excavator. One motor was added for each of the two tracks to allow the machine to drive forwards, backwards, and turn. Two more motors were added to raise and lower the digging buckets, and spin the tower. Finally, the original motor was left in place to turn the conveyor.
With that done, [Frank] then used a Raspberry Pi 3 to control all the hardware, being sure to house the new electronics in LEGO for an original look. The Raspberry Pi might be a lot of muscle to simply control a few motors, but it made it quick and easy for [Frank] to implement a Wiimote as a controller over Bluetooth. You can check out a couple demo videos in his most recent update.
You’ve just got to go with the hype on this one, because it’s obviously not ready for prime time yet. But a few days ago murmurs started circling the net that an Australian inventor had developed a robot capable of building complicated structure from brick all by itself.
Before you go off your rocker… we’re definitely not calling this real. It’s a proof of concept at best, but that doesn’t prevent us from getting excited. How long have you been waiting for robots that can build entire structures on our behalf? We were excited at the prospect of extruding walls of concrete. But this is more like LEGO buildings in the real world. The beast cuts brick to length, conveys each brick along the telescoping arm, and butters them as it lays them in place. At least that’s what the rendered video after the break shows.
We’re hearing about this now because FastBrick Robotics, the company [Mark Pivac] founded and has spent ten years developing the Hadrian project at, was just sold to a company called DMY Capital Limited. Of course they’re going to want to get some press out of the sale.
There is an image of the brick feeder on an existing excavator that frankly looks photoshopped. And some real images like the one seen here and another of the “print head” holding some bricks. But it’s enough to think there’s potential here.
The idea is that the base of the robot is fixed with the arm long enough to reach any part of the structure being built. Precise positioning is achieved by a fixed marker in a different position from the robot. The head triangulates its position using laser range-finding with the marker (having said that we now assume there needs to be more than one marker).
So what do you think? Are we ever going to see this incredibly complicated bucket of awesome producing structures in our neighborhood which the Big Bad Wolf simply cannot blow down?