gas cylinder

3 Articles

Scrapyard Vacuum Dehydrator Sucks The Water From Hydraulic Oil

February 16, 2025 by 23 Comments

Anyone who has ever had the misfortune of a blown head gasket knows that the old saying “oil and water don’t mix” is only partially true. When what’s coming out of the drain plug looks like a mocha latte, you know you’re about to have a very bad day.

[SpankRanch Garage] recently found himself in such a situation, and the result was this clever vacuum dehydrator, which he used to clean a huge amount of contaminated hydraulic fluid from some heavy equipment. The machine is made from a retired gas cylinder welded to a steel frame with the neck pointing down. He added a fill port to the bottom (now top) of the tank; as an aside, we had no idea the steel on those tanks was so thick. The side of the tank was drilled and threaded for things like pressure and temperature gauges as well as sight glasses to monitor the process and most importantly, a fitting for a vacuum pump. Some valves and a filter were added to the outlet, and a band heater was wrapped around the tank.

To process the contaminated oil, [Spank] glugged a bucket of forbidden milkshake into the chamber and pulled a vacuum. The low pressure lets the relatively gentle heat boil off the water without cooking the oil too badly. It took him a couple of hours to treat a 10-gallon batch, but the results were pretty stark. The treated oil looked far better than the starting material, and while it still may have some water in it, it’s probably just fine for excavator use now. The downside is that the vacuum pump oil gets contaminated with water vapor, but that’s far easier and cheaper to replace that a couple hundred gallons of hydraulic oil.

Never doubt the hacking abilities of farmers. Getting things done with what’s on hand is a big part of farm life, be it building a mower from scrap or tapping the power of the wind.

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Gas-Powered Fly Swatter Slightly Over-Engineered

July 10, 2023 by 10 Comments

Any good flyswatter ought to be able to break through a hefty piece of wood. At least, that is how [Finn] explains the design philosophy behind this enormous, overpowered flyswatter. Although we don’t know if everyone needs as robust a machine as this to deal with a minor annoyance like a house fly, we can certainly appreciate the over-engineered, extremely powerful (and dangerous) machine that can swat flies but also break through a two-by-four with ease.

The build comes to us in two parts, with the first part documenting the construction of some of the parts of the flyswatter, including the piston-driven gas cylinder. As a bit of a tangent, [Finn] first tests this part by using it to shoot lemons at pieces of plywood. After this initial testing of the gas cylinder, a cam mechanism is installed on the top, and the gas cylinder is slightly modified to pull on a piece of Dyneema rope attached to the cam. At the other end of the rope is a long metal lever with the flyswatter on the end, in this case, made out of a sheet of laser-cut plate steel.

With the addition of a few safety features, like a spring-assisted bumper to keep the flyswatter from swinging too far and hitting its operator, the machine is ready for use. It also eventually received some other upgrades as well including extra weights to prevent the flyswatter from bouncing after firing and a reinforced metal rod to hold the flyswatter after its demonstrations on various dimensional lumber destroyed it. In all likelihood, this is the largest insect-control device we’ve seen since this microwave-powered bug zapper. Now if you are building an insect…

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Bicycle Transforms Mid-Ride

November 13, 2019 by 9 Comments

For those of us who were children in the late 80s and early 90s, we may have dreamed of one day owning a gigantic tractor trailer that could transform into a colossal fighting robot. Or of simply having a toy that could approximate this change from one form into another. As adults, though, we have come to realize that this is wishful thinking. That is, unless we decide to build this transforming bicycle.

What starts out as a slightly unusual-looking low rider-style bike effortlessly turns into a tall bike by means of a gas cylinder fixed to the bike’s rear triangle. The bike started out as a full suspension mountain bike, but the rear spring was removed to make room for this cylinder. The pivoting action of the rear triangle in a mountain bike is the key design element here: it allows the frame to change shape easily, in this situation when pushed by the cylinder. Adding some longer forks in the front and a coat of paint finishes the build.

This bike was entered in the Make It Move contest on Instrucables, and has gotten some pretty wide recognition so far. It’s a unique bicycle to be sure, and we’ve seen a few. From Russian offroad electric utility bicycles to bicycles that keep drivers from speeding down roads, there have been lots of interesting bike-based builds.

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