We’ve all seen a movie or TV show that got our imagination going, and the more studious of us might get fired up over a good book (one without pictures, even). You never know were inspiration might come from, which is why it’s so hard to track down in the first place. But one place we don’t often hear about providing many hackers with project ideas is the grocery store. But of course the more we learn about [Michael Kohn], the more we realize he’s got a very unique vision.
On a recent trip to the grocery store, [Michael] saw a two pack of frozen lobsters and thought they would make fine battling robots. You know, as one does. Unfortunately the process of taking a frozen lobster and turning it into a combat droid (which incidentally does include eating the thing at some point in the timeline) ended up being so disgusting that he only finished one of them. Whether that makes this poor fellow the winner or loser though…that’s a question that will require some contemplation.
The first step was cooking and eating the beast, and after that came cleaning the shell of as much remaining meat and innards as possible. He then baked it in a toaster oven for 40 minutes and let it sit for a couple of days to make sure it didn’t have any residual smell. Once he confirmed the shell was clean, he glued it back together and got started on mounting it to his hardware.
A wooden frame under the lobster holds the dual HD-1711MG mini servos that power the karate chop action of the claws, as well as the electronics. [Michael] used a ATtiny85 and NTD4963N MOSFETs to make a basic RC platform which responds to IR from a Syma S107 toy helicopter controller. He tried to power everything with AAA and then AA batteries, but found they just didn’t give him the juice he needed once the bot got going. So the final version utilizes a 5 V regulator and a standard RC 7.2v LiPO battery pack.
[James Bruton] is well known for making robots using electric motors but he’s decided to try his hand at using pneumatics in order to make a fighting robot. The pneumatic cylinders will be used to give it two powerful punching arms. In true [James Bruton] fashion, he’s started with some experiments first, using the pneumatic cylinders from foot pumps. The cylinders he’s tried so far are taken out of single cylinder foot pumps from Halfords Essentials, costing only £6.29, around $8.11 US. That’s far cheaper than a commercial pneumatic cylinder, and perfectly adequate for this first step.
He did have to hack the cylinder a little though, besides removing it from its mounting and moving it to a DIY frame. Normally when you step down on a foot pump’s lever, you compress the cylinder, forcing air out the hose and into whatever you’re inflating. But he wanted to push air in the other direction, into the hose and into the cylinder. That would make the cylinder expand and thereby extend a robot fighting arm. And preferably that would be done rapidly and forcefully. However, a check valve at the hose outlet prevented air from entering the cylinder from the hose. So he removed the check valve. Now all he needed was a way to forcefully, and rapidly, push air into the hose.
For that he bought a solenoid activated valve on eBay, and a compressor with a 24 liter reservoir and a decent air flow rate of 180 liters per minute. The compressor added £110 ($142) to the cost of his project but that was still cheaper than the batteries he normally buys for his electric motor robots.
After working his usual CAD and 3D printing magic, he came up with an arm for the cylinder and a body that could fit two more valve activated cylinders to act as a working shoulder. A little more 3D printing and electronics, and he had 3 switches, one for each valve and cylinder. He then had the very successful results his experiment. You can see the entire R&D process in the video below, along with demonstrations of the resulting punching robot arm. We think it’s fairly intimidating for a first step.
The folks at Fetch Robotics do love a good game of combat robots. Time is tight these days, however, so putting together a good ol’ 220-pounder for Robogames is a dream few of us can realize. Instead, the Fetch team hosted their own Plastic fantastic battlebots competition to blow off some steam, and the results are in!
Battlebots enter the ring built from a frame of entirely plastic parts and weighing a humble 3lbs. Just like Battlebots and Robogames, they’ll follow a 2-minute episode of hack-and-slash after which judges determine the winner. Bots were forged from everything you might see in arms reach of your local hackerspace: pvc pipe, acrylic sheets, and a few 3D-printed components. On the menu of shredded plastic we have everything from classic wedges and spinners to a giant spinning rubber pterodactyl strapped onto the body of an RC car. (Time is tight, right?)
While 3 pound plastic fighters might not seem devastating, don’t underestimate the LiPo batteries and brushless motors that are running under the hood. These competitors can easily heave each other across the ring. We’ve definitely seen mini Battlebot tournaments before, and we’re thrilled to see them on the rise in everyday places. Better start getting your materials ready. Who knows? Mini Battlebots might be coming to an alley near you too.
“Ahhhh! They’re so cute! Wait a second, does that little robot have a spinning blade of death?!?!?” Yes, yes it does.
Welcome to Bristol University 2nd Annual Robot Wars Tournament. It’s loosely based on the old BBC show Robot Wars, where contestants would design and build fighting robots. This pint-sized version is just down right fun to watch. But don’t let their size fool you, some of these little bots pack a mean punch.
This competition follows the “Antweight World Series Rules” and must fit inside a 4 inch cube with a max weight of 150 grams. There are some not-so-fun rules attached to that, such as “No flame based weapons” and “no use of electricity as a weapon.” But hey, it still looks like a blast.
We can’t help but to think that a contest like this would be an amazing thing for local hacker spaces to set up and organize. The playing field seems to be a reasonable size, such that it could be set-up and torn-down without too much hassle. And with RC transmitters/receivers available so inexpensively these days, and ebay flooded with little robot parts from China, now seems like a perfect time to start a local robot competition. It might be a great way to draw people into making and hacking. You can watch the video of the competition and meet the makers after the break.