Electronic float valve keeps the horse’s feet dry

[Bob] built this simple device that can best be described as an electronic float valve. He was wasting a lot of water from overflowing water troughs and buckets around his farm. He would usually put the hose in the container, turn on the water valve and carry on with his work. By the time he remembered to come back, the area would be flooded. It’s obvious that there’s many different ways to solve a problem. For example, a simple mechanical float valve might have worked, but it’s not horse friendly and liable to get damaged soon.

The electronics is unabashedly minimal. An ATtiny85 controls a relay via a common variety NPN transistor. The relay in turn switches the solenoid valve. A push-button tells the microcontroller to start the water flowing, and when the water level gets high enough that it touches two hose clamps, the micro shuts it off again.

There’s some ghetto engineering going on here. The electronics is driven by a 9V battery, although the relay and the solenoid valve that [Bob] used are both rated for 12V. He’s not even using any sort of voltage regulation for the ATtiny, but instead dropping the voltage with a resistor divider. (We wonder about battery life in the long run.)

He built all of it on perf board and stuffed it inside a small enclosure, with two wires coming out for the level sensor and another two for the solenoid, and it seems to work. Check the video below where [Bob] walks through his build.

While some may point out the many short comings in this build, [Bob] found the one solution that works for him. Sometimes the right solution is what you’ve got on hand, and we’re glad he’s hacking away and sharing his work. And check out this wireless water level sensor that he built some time back.

Continue reading “Electronic float valve keeps the horse’s feet dry”

Homemade Bazooka Has Earned Its Stripes

Many of us dream of launching rockets from our shoulders, but [John] here actually did something about it.

This bazooka build started with a 6″ diameter PVC pipe. He mounted a length of 80/20 T-slotted aluminum extrusion to the pipe through a couple of wood blocks. [John] installed rail buttons on some Estes Alpha rockets which slide along nicely inside the T-slot. He welded a PVC cleanout fitting and plug to one end for easy access and gave her a nice paint job.

The ignition is simple: an irresistible red push button is wired to a 9V battery and a pair of alligator clips. [John] loads up a rocket, puts the gators on the wires of an igniter, pushes said button, and Bob’s your uncle. All he needs now is a pair of gun boats. Video of the build and some demonstrations we don’t necessarily recommend are after the jump.

Continue reading “Homemade Bazooka Has Earned Its Stripes”

Paintball gun silencer

In paintball, the element of surprise can make the difference between victory and defeat. While we can’t help you with the sounds of labored breathing and shuffling feet as you waddle across the field, we did find this guide on how to make a silencer for your paintball gun.

To build this you will need two lengths of PVC pipe, one slightly larger in diameter than the barrel of the gun, the other about 1″ beyond that. You will also need PVC reducers that fit the pipes, cotton balls, and various cutting and finishing tools. Cut the stopper tab from the smaller pipe and put into a reducer, hammering the reducer into place. Cut the pipe about 1″ away from the reducer, being careful to make the cut as even (perpendicular to the length of the pipe) as possible. Now drill six straight lines of ten holes along the pipe with the smallest drill bit possible. Sand down the inside of the pipe by wrapping sandpaper around a cylindrical stick and move the stick in and out of the pipe. Cut the larger pipe so that it is slightly shorter than the smaller pipe. Fit the two pipes together and fill the area between the two with about 20 cotton balls. After that, fit the second reducer to the other end. At this point the silencer is functional, but guide author [MrAngryPants] suggests painting it black.

As the paintball and CO2 are expelled from the gun, the cotton baffles dampen the resulting sound wave.