If you’ve never seen Applied Science, Ben Krasnow’s YouTube channel, you need to go subscribe to it now. Ben does the most fascinating videos exploring practical applications of science and high technology. Whatever the subject, he patiently, clearly, and methodically runs through the experiments he undertook, the hardware he used, what he discovered, what issues he encountered, and what he concludes from his efforts. I feel smarter and more aware of how the world around me actually works after watching Ben’s videos.
In this installment of Applied Science, Ben does something truly noteworthy. He creates a usable waterjet cutter, capable of cutting through metal, wood, and other material. He accomplishes this using a rig he put together for only a few hundred dollars. The heart of the system is a Sun Joe pressure washer that he bought for $150 on Amazon. A commercial waterjet cutter costs tens of thousands of dollars. Even a super-low-end cutter, like the Wazer, crowdfunded on Kickstarter a few years ago, sells for $6,0000.
Ben’s cobbled-together rig might not look like much, but it does get the job done. In the video, you see him cutting through 1/16″ aluminum (at ~2″/min with .4 lbs/min of abrasive @3200psi), 1/8″ aluminum (at about 1/2 the cutting speed, abrasive and psi values the same), 3/8″ hardwood, styrofoam (in water-only/no abrasive mode), and bread (yes, bread).
The water cutter he creates is mainly comprised of the pressure washer (which he had to make a few simple modifications to), a water orifice, mixing tube (nozzle), cutting head, high pressure fittings, a pressure gauge, and a valve. He got most of these parts at AccuStream (a waterjet parts supplier) and McMaster-Carr.
For the abrasives hopper, after doing research into commercial hoppers, he realized that they’re basically just a gravity-fed tub with a hole in the bottom (and a means of adjusting the amount of abrasive). So, he made his own. A list of the parts used and links to suppliers are provided in the video description.
Ben concludes that all-in-all, a funky, homebrewed set-up like this is actually quite usable. It can’t cut at the speeds of a commercial machine, but for hobby and small shop use, it might just be the ticket. You sure can’t beat the price! At the end of the video, Ben talks about how he might take it to the next level by outfitting it with a cheap CNC bed to make cutting automated and computer-controlled. Creating some sort of containment for the whole unit would make sense, too, if you’re planning to use the device for real, day-to-day work.