You Can Put Toothpaste In The Tube (With Effort)

July 5, 2021 by Bryan Cockfield 20 Comments

Old wives’ tales, folk knowledge, common sayings, and even cliches and idioms are often taken as givens since they form an often unnoticed part of our vocabulary and culture. There’s so many examples that it’s possible to fill a 17-season TV show busting potential myths like these, and even then there are some that slipped by. For example, the saying “you can’t put toothpaste back in the tube” which, as it turns out, is not as impossible as we might be led to believe.

This video is the product of [Tyler Bell] who has taken this idiom on as a challenge. To figure out if it was possible he first got to work building a vacuum chamber, which turned out to be a little easier than he thought it would be. After cutting a piece of polycarbonate tube and sanding it down, all that was needed were some rubber gaskets and fittings for the vacuum pump.

From there, the theory was to put an empty toothpaste tube into the vacuum chamber, pump all of the air out, and let atmospheric pressure “push” the toothpaste back into the tube. During [Tyler]’s first run he thought that it had worked successfully but it turned out that he had just inflated the empty toothpaste tube like a balloon. Further iterations were able to return some of the toothpaste to the tube, but each time some air would eventually work its way into the toothpaste which would immediately fill the remaining space in the tube with air rather than toothpaste.

While not completely successful, he was able to get some toothpaste back into the tube with a relatively small bill of materials. It’s not likely that this experiment will result in a change of this particular idiomatic expression, but it was interesting to put it to the test nonetheless. For other instances of toothpaste and its relationship to tubes, both inside and out, be sure to check out this recent piece on various methods of toothpaste storage.

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Hacked Vacuum Chamber Won’t Suck A Hole In Your Budget

August 4, 2018 by Dan Maloney 38 Comments

There’s nothing like a true hack, where something useful is concocted from bits of scrap and bargain store finds. Builds like these are much more than the sum of their parts, especially when they result in a useful tool, like this DIY vacuum chamber that’s good for all sorts of jobs.

Everything [Black Beard Projects] used to accomplish this build is readily available almost everywhere in the world, although we have to note that appliance recycling efforts and refrigerant recovery programs have made it somewhat harder to lay hands on things like the old fridge compressor used here. The big steel cooking pot is an easy thrift store find, though, and while [Black Beard] used high-quality stainless fittings and valves to plumb the chamber, pretty much any cheap fittings will do.

The one sketchy area of the build is the plexiglass sheet used for the chamber top, which seems a little on the thin side to us. You can see it flexing in the video below as vacuum is pulled; it survived, but we can see it failing catastrophically at some point. We stand ready to be reassured in the comments. Still, it’s a tidy build with a few nice details, like wiring a switch into the old start capacitor box and using car door edge protector as a gasket on the chamber.

Fridge compressor hacks are standard fare, of course, being used to make everything from air compressors to two-stroke engines. Sometimes they’re even used to keep things cool too.

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Nerf Blaster Goes Next-level With Propane Power

April 21, 2018 by Ben James 14 Comments

There are no shortage of Nerf gun mods out there. From simply upgrading springs to removing air restrictors, the temptation of one-upping your opponents in a Nerf war speaks to many!

Not content with such lowly modifications [Peter Sripol] decided that his blaster needed to see some propane action.

[Peter] completely stripped out the existing firing mechanism before creating a new combustion chamber from some soldered copper pipe. He added a propane tank and valve on some 3D-printed mounts, and replaced the barrel to produce some intense firepower.

To ignite the fuel inside the combustion chamber, some taser circuitry creates the voltage needed to jump the spark gap inside whilst an added switch behind the trigger kicks off the whole process. After experimenting with different ignition methods, [Peter] eventually found that positioning the spark in the center of the chamber provided the best solution for efficient combustion and non-deafening volume.

Though highly dependant on the amount of gas in the chamber during combustion, the speed of the dart was able to reach a maximum of 220 fps – that’s a whopping 150mph!

Next follows the obligatory sequence for all souped-up Nerf guns: slow motion annihilation of various food items and beverage containers. To obtain some extra punch, some custom Nerf darts were 3D-printed, including one with a fearsome nail spear-head.

We strongly advise against taking up [Peter] on any offer of Nerf based warfare, but you can check out his insane plane adventures or last winter’s air sled.

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