Behold the Robopult:
Every hacker wants a budget to do bigger, cooler hacks. Well, we got our budget, all $1000 of it, and decided to turn a borrowed industrial robot into a catapult, a hack we’d been hoping to do for a long, long time. We’d been joking about throwing heavy objects with one of these robots ever since we saw the payload specs and an anvil in the shop.We wanted to make a catapult that could destroy a car with bowling balls from at least 80 feet away, throw fireballs, and be controlled through a computer vision system so it could be aimed from a laptop. Result? Success.
It’s a shame the software targeting software didn’t quite work out:
When we got to the desert and actually threw some bowling balls I quickly realized two things:
- The range of the projectile scaled strangely, at best, and the robot threw past our 100′ tape, so we would have limited data for a scaling function. For example, dropping the speed of the swing to 75% yielded about half of the distance of 100% power, but 87.5% power yielded about two-thirds of the distance of 100% power.
- I didn’t bring a long enough usb cable so my laptop and I had to be within 3 feet of the base of robot to hit the serial send command. This wasn’t going to happen; I was not going to chance bowling ball-induced death by a catapult that was over 26′ tall at full swing.
Our solution was to abandon ranging, try targeting a few times by just manually punching in the numbers from the laptop into the controller. We finally just gave in to manually typing in the target angles into the robot, which made for some amusing trial and error.
(Hat tip to mon père.)