When we think of a vacuum leak we generally think of a car that just doesn’t want to run quite right. Most normally aspirated internal combustion engines rely on the vacuum created by the pistons to draw in the air fuel mixture that’s produced by the carburetor or fuel injection system. Identifying the leak usually involves spraying something combustible around common trouble areas while the engine is running. Changes to the engine speed indicate when the combustible gas enters the intake manifold and the leak can be found.
What if your vacuum leak is in a highly specialized piece of scientific equipment where the pressures are about 12
times orders of magnitude lower than atmospheric pressure, and the leak is so small it’s only letting a few atoms into the vacuum chamber at a time? [AlphaPhoenix] takes dives deep into this very subject in his video “Air-tight vs. Vacuum-tight.” which you can watch below the break.
Not only does [AlphaPhoenix] discuss how a perfect pressure vessel is sealed, he also explains the specialized troubleshooting methods used which turn out not to be all that different from troubleshooting an automotive vacuum leak- only in this case, several magnitudes more complex and elemental in nature.
We also enjoyed the comments section, where [AlphaPhoenix] addresses some of the most common questions surrounding the video: Torque patterns, the scarcity of the gasses used, and leaving well enough alone.
Does talking about vacuums get you pumped? Perhaps you’d enjoy such vacuum hacks as putting the toothpaste back in the tube in your homemade vacuum chamber.
Thank you [Morgan] for sending this one in. Be sure to send in your own hacks, projects, and fantastic finds through the Tip Line!
Continue reading “Solving Ultra High Vacuum Leaks Has An Elementary Solution”
We know it all too well: another smoothly-operating night in the garage easily halted by a broken component. In the late hours of the night, no hardware store will open its doors. And while waiting may reward the patient, creativity may reward those who act now. That’s exactly where [Justin] found himself one evening: with a torn gasket. Not to be dismayed, he turned to his fiancee [Amy] and the two of them managed to design and cut a perfectly fitting replacement gasket on [Amy’s] vinyl cutter in a mere matter of minutes.
In the video after the break, the two step us through their process in detail. By starting with an image of the existing gasket, they capture a reference image. Some light work in photoshop cleans up everything except the resulting gasket they’re looking for. Finally, sizing “by eye” in the vinyl cutter’s software after measuring an existing dimension gives them sufficient precision to remake a duplicate gasket that’s eye-for-eye indistiguishable from the original.
It seems like we often hear about vinyl-cut gaskets in passing or in the comments, but it’s great to see a team post such a fabulous success story putting them to good use. And in case a plain old’ vinyl cutter blade wont do the trick, why not try running it at ultrasonic speeds?
Continue reading “Vinyl Cutter Migrates From Scrapbooks To Gaskets”
It’s the suburbanista’s weekend nightmare: you’re almost done with the weekly chores, taking the last few passes with the lawn mower, when you hear a pop and bang. The cylinder head on your mower just blew, and you’re out of commission. Or are you? You’ve got a 3D printer – couldn’t it save the day?
If this bench test of plastic cylinder heads is any indication, it’s possible – just as long as you’ve only got 40 seconds of mowing left to do. [Project Farm] has been running all sorts of tests on different materials as field-expedient cylinder heads for small gasoline engines, using everything from JB Weld epoxy to a slab of walnut. For this test, two chunky heads were printed, one from ABS, of the thermochromic variety apparently, the other in PLA. The test went pretty much as expected for something made of thermoplastic exposed to burning gasoline at high pressure, although ABS was the clear winner with two 40-second runs. The PLA only lasted half as long before the spark plug threads melted and the plug blew out. A gasket printed from flexible filament was also tested, with predictably awful results.
As bad as all this was, it still shows that 3D-printed parts are surprisingly tough. Each part was able to perform decently under a compression test, showing that they can stand up to pressure as long as there’s no heat. If nothing else, it was a learning experience. And as an aside, the cylinder heads were printed by [Terry] from the RedNeckCanadians YouTube channel. That video is worth a watch, if just for a few tips on making a 3D-printed copy of an object. Continue reading “Results Of 3D-Printed Cylinder Head Testing Fail To Surprise”
[Ben Krasnow’s] water vortex machine has been an exhibit in the lobby of the San Jose City Hall for quite some time now. Unfortuantely he recently had to perform some repair work on it due to the parts inside the water chamber rusting.
This is the same water vortex that we saw about a year ago. It uses a power drill to drive an impeller at the bottom of a water column to produce the vortex. That impeller was made from painted steel and after being submerged for eight months it began rusting, which discolored the water. [Ben’s] repair process, which you can watch after the break, replaces the shaft and the impeller. He reused a plastic PC cooling fan as the new impeller. The replacement shaft is stainless steel, as is all of the mounting hardware that will be in contact with water. But for us, the most interesting part of the repair is his explanation of the shaft gasket and bearings. Two thrust bearings and two radial bearings ensure that the shaft cannot move axially, which would cause a problem with the gasket. He had intended to swap out the oil seal for an all Teflon seal but the machined acrylic wasn’t conducive to the part swap. Instead, he replaced it with the same type of gasket, but bolstered the new one with some silicone to stave off corrosion.
Continue reading “Water Vortex Exhibit Repair Gives A Look At The Bearing And Gasket Design”