PVC ROV is a study in MPV

Low Buck PVC ROV IS Definitely A MVP

Do you have a hundred bucks and some time to kill? [Peter Sripol] invites you to come along with him and build a remotely operated submarine with only the most basic, easily accessible parts, as you can see in the video below the break.

Using nothing more than PVC pipe, an Ethernet cable, and a very basic electrical system, [Peter] has built a real MVP of a submarine. No, not Most Valuable Player; Minimum Viable Product. You see, there’s not a microcontroller, motor controller, sensor, or MOSFET to be found except for that which might reside inside the knock-off GoPro style camera which is encased in a candle wax sealed enclosure.

Instead, simple brushed motors live right out in the open water. Single pole double throw switches are connected to 100 feet of Ethernet cable and control the relays powering the motors. The camera signal is brought back to the controller through the same cable. Simple is the key to the build, and we have to admit that for all of its Minimum Viability, the little ROV has a lot going for it. [Peter] even manages to use the little craft to find and make possible the retrieval of a crustacean encrusted shopping cart from a saltwater canal. Not bad, little rover, not bad.

Also noteworthy is that the video below has its own PVC ROV Sea Shanty, which is something you just don’t hear every day.

Underwater ROV builds are the sort of thing almost every hacker thinks about doing at least once, and some hackers even include Lego, magnets, and balloons in their builds! Continue reading “Low Buck PVC ROV IS Definitely A MVP”

A New Spin On A Medical Test

Most of us can say that we have taken an obsolete hard drive out of a computer and felt it was a waste to toss it in the e-waste pile. Some of us have children’s drawings hung on the fridge with actuator magnets, or maybe a vast spreadsheet suspended on a steel filing cabinet. Let us not forget that there is also a high-speed, low-noise motor in there. On some models it is separate from the PCB, so grab an Electronic Speed Controller (ESC), your microcontroller of choice, and make yourself a salvaged HDD centrifuge like [Cave Man] has. His build uses the tray as a chassis, but he modeled and printed a new face in the same style as the original.

On top, he has an OLED screen for displaying the requested speed, measured speed, and runtime. Next to the display is a four-button pad with a customized legend for setting parameters. The video after the break shows the machine running through its paces. This version accommodates the tiny capillary tubes, microhematocrit tubes, for processing raw blood. This test can calculate the packed cell volume, which professionals use to determine things from dehydration to anemia.

There are other builds out there where people have modified an old drive into the kind of centrifuge that accepts larger diameter tubes, but this was a shining example of what is possible. One good turn deserves another, so we recommend a desktop bio-lab companion, or enlist some LEGO Mindstorms to help out.

Continue reading “A New Spin On A Medical Test”