Fail of the Week: Arachno∙fail∙ia

Going down the list (FCC, CE, UL, etc.) we can’t think of a regulating body that will test for this failure mode. Reportedly, a $1M irrigation system was taken down by a spider. And an itsy-bitsy spider at that.

This fail turned up as a quick image post over on /r/mildlyinteresting but I wasn’t the only electronics person attracted like a moth to a flame. Our friend [Sprite_TM] popped in to answer a question about conformal coating. Seems this board was sealed in a waterproof enclosure but was obviously not conformally coated.

fotw-spider-short-relay-diagram[Sprite_TM] also helped out with some armchair-engineering to guess at what happened. It’s not hard to tell that the footprint on the board looks like a set of mechanical relays all in a line. He looked up the most likely pinout for the relay.

We’ve superimposed that pinout on the board to help illustrate the failure. High voltage comes in on the pin shown with the red trace leading away from it. On either side of that pin are the connections for the low voltage coil which switches from normally closed (the pin in the upper right that is not connected to anything) to the normally open pin (which has the wide trace leading away from it).

So there sat the high voltage pin in between the coil pins when, along came a spider. It shorted the pins and presumably all the way back to the power supply for the low voltage rail. [Fugly_Turnip] (the OP) share some additional detail about the system and this failure; in addition to this card it fried the control module as well.

Another comment on the same thread shares a different story of two boards mounted next to each other with a bug shorting a 1/4″ air gap between two boards and causing similar carnage. Have you encountered Arachno-fail-ia of your own? Let us know below.

Hexapod Tank from Ghost in the Shell Brought to Life

Every now and then someone gets seriously inspired, and that urge just doesn’t go away until something gets created. For [Paulius Liekis], it led to creating a roughly 1:20 scale version of the T08A2 Hexapod “Spider” Tank from the movie Ghost in the Shell. As the he puts it, “[T]his was something that I wanted to build for a long time and I just had to get it out of my system.” It uses two Raspberry Pi computers, 28 servo motors, and required over 250 hours of 3D printing for all the meticulously modeled pieces – and even more than that for polishing, filing, painting, and other finishing work on the pieces after they were printed. The paint job is spectacular, with great-looking wear and tear. It’s even better seeing it in motion — see the video embedded below.

Continue reading “Hexapod Tank from Ghost in the Shell Brought to Life”

Learning Single-Filament Printing Strength from Arachnids

If you can get over how creepy spiders can be there’s a lot to learn from them. One of nature’s master-builders, they have long been studied for how they produce such strong silk. What we hadn’t realized is that it’s not strictly cylindrical in nature. The spider silk exhibits intermittent expansions to the diameter of the — for lack of a better word — extrusion. This project uses biomimickry to replicate the strength of that design.

The print head is actually four extruders in one. In the clip after the break you can see the black center filament’s rigidity is augmented with three white filaments positioned around it radially. The use of this knowledge? That’s for you to decide. As with some of the most satisfying engineering concepts, this is presented as an art installation. As if the rhythmic movements of that print head weren’t enough, they mounted it on a KUKA and plopped the entire thing down in the center of a room for all to see.

The demo isn’t the only awesome bit. You’ll want to click the link at the top to see the exploded-parts diagram porn found half-way down the page. All is beautiful!

Continue reading “Learning Single-Filament Printing Strength from Arachnids”

Six years, a giant robot, and a kickstarter

robot

Since 2007, [Jamie Mantzel] has been building a huge remote-controlled walking robot. If you’ve been following him on his YouTube channel and blog, you’ve seen the very beginnings of him building a lumber mill to create a workshop, making the legs for his robot, and improving his welding rig. This week, though, has been very special. [Jamie] has finally finished his giant robot project, bidding closed the fevered dream of a madman who awakes to a 10 foot robot in his yard.

The giant robot is constructed nearly entirely out of scrap aluminum. In the interest of simplicity, [Jamie] has come up with some interesting techniques to scale up conventional RC gear to power huge motors swinging giant legs: the steering motors are powered by manual switches, but these switches are activated by servos. A brilliantly simple solution to driving high-current loads if we do say so ourselves.

[Jamie]’s robot has garnered a lot of attention over the years, so much so that toy companies have licensed his designs for a line of battling combat spiderbots. [Jamie] believes his robots should be more educational, so he’s launched a Kickstarter for his own version as a kit. With this kit, getting the bug tank robot up and running isn’t simply a matter of pulling it out of the box and installing batteries; [Jamie]’s version is an actual kit with linkages that must be assembled. We know which version we’d want.

It’s an amazingly impressive project, and we’re glad to see such an awesome cat has finally realized his dream of a walking aluminum arachnid of death.

Snake-like robot can roll around in a ring

A lot of 3D printing and a many servo motors went into this snake-like robot, and it’s only about half of what [Toby Baumgartner] plans to accomplish. In this orientation the snake is rolled into a circle, and apparently some special movements in the segments allow it to roll around like this. He compares it to a tank tread without the tank attached to it. Notice that each link is rounded on the outside. When the snake opens itself up, the toothed inside of the links contacts the ground for added traction.

It looks like eventually the larger link at the bottom will be about three times as wide. This will make room for him to mount a second ring of links. The idea is that the larger link will act as the body and this can unfold itself into a quaruped. Motors that allow the segments to pivot side to side would make it something like a four-legged spider bot.

ArduSpider entertains children and exercises pets

There are so many good things about [Jose Julio’s] robotic spider. It’s design is dainty yet robust, and the behaviors encoded in the firmware are nothing short of spectacular.

The body is built from a piece of balsa wood in between sheets of carbon fiber. The legs are carbon rods, using two servo motors for left and right leg movement, and a third servo which can move the intermediary legs like the roll axis of a plane. An IR sensor rides on the front for obstacle avoidance, with system control courtesy of an Arduino. For more hardware info check out his build log.

Don’t miss the video after the break. You’ll see that the little bot can be manually controlled, or allowed to roam free. As we said before, the behavior is fantastic. Not only has [Jose] programmed interesting characteristics like the spider getting tired and sitting down for a while, but when it is awakened it leaps into the air. The movements are fun to watch for human and feline alike; if only your house cat could be so lucky.

Continue reading “ArduSpider entertains children and exercises pets”

Mondo Spider

This vehicle is aptly named the Mondo Spider. It’s not from some apocalyptic movie, but seen here at Burning Man. Like a lot of Burning Man exhibitions, it was built for the joy of the build and with a rather extreme budget: $15,000. We’ve embedded one of the many videos after the break, as well as a few of the hardware details.

Continue reading “Mondo Spider”