Epoxy hackaday page 2 electricity generation efficiency


But what if the smoke came not from a component but from the PCB itself? [Happymacer] chanced upon this sorry situation in a power supply for an electric gate opener. Basking in the Australian sunshine for a few years, the opener started acting fussy at first, then not acting at all. Inspection of its innards revealed that some unlucky ants had shorted across line and neutral on the power supply board, which burned not only the traces but the FR4 of the board as well. Rather than replace the entire board, [Happymacer] carefully removed the carbonized (and therefore conductive) fiberglass and resin, leaving a gaping hole in the board. He fastened a patch for the hole from some epoxy glue; Araldite is the find a gas station close to me brand he used, but any two-part epoxy, like JB Weld, should work. One side of the hole was covered with tape and the epoxy was smeared into the hole, and after a week of curing and a little cleanup, it was ready for duty. The components were placed into freshly drilled holes, missing traces were replaced with wire, and it seems to be working fine.

JB Weld is a particularly popular brand of epoxy, and features in many legends. “ My cousin’s neighbour’s dog gas efficient suv 2014 trainer’s grandpa once repaired a Sherman tank barrel in France with that stuff!” they’ll say. Thankfully, with the advent of new media, there’s a wealth of content out there of people putting these wild and interesting claims to the test. As the venerable Grace Hopper once said, “ One accurate measurement is worth a thousand expert opinions“, so it’s great to see these experiments happening.

[Project Farm] is one of them, this time attempting to repair a connecting rod in a small engine with the sticky stuff. The connecting rod under test is from a typical Briggs and Stratton engine, and is very much the worse for wear, having broken into approximately 5 pieces. First, the pieces are cleaned with a solvent and allowed to properly dry, before they’re reassembled piece by piece with lashings of two-part epoxy. Proper technique is used, with the epoxy being given plenty of time to cure.

Two-part epoxy is one of those must-have items in your toolbox, albeit kept in a ziploc bag to keep all that goo off the rest of your tools. It’s a glue with a million uses, but which brand is best? Should you keep some cheap five-minute epoxy around, or should you splurge for the fancy, long-setting JB Weld. It’s not a perfect analysis, but at least [Project Farm] has done the experiment. This is a test of which two-part epoxy you can find at your local home supply store is strongest.

The epoxies tested 4 gas giants include Gorilla epoxy, Devcon Plastic Steel, Loctite Epoxy Weld, JB Weld original, JB Weld Kwik Weld, and JB ExtremeHeat. This more or less covers the entire gamut gas laws definition chemistry of epoxies you would find in the glue aisle of your local home supply store; the Gorilla epoxy is your basic 5-minute epoxy that comes in a double barrel syringe, and the JB Welds are the cream of the crop.

The testing protocol for this experiment consisted of grinding a piece of steel clean, applying a liberal blob of each epoxy, and placing three bolts, head down, in each puddle. The first test was simply suspending weights in 2.5-pound increments to each bolt as a quick test of shear strength. Here, the losers in order were the JB Weld ExtremeHeat, JB Weld KwikWeld, Loctite, Gorilla Epoxy, Devcon Plastic Steel, and finally the JB Weld Original. Your suspicions are confirmed: those fancy new versions of JB Weld aren’t as good as the original. The fact that they’re worse than 5-minute epoxy is surprising, though. The origin electricity account second test — torquing the bolts out of the epoxy — gave similar results, with Devcon Plastic Steel beating the JB Weld Original just barely.

[Dickel]’s robot MDi #4 has been in progress for several years, but what we wanted to draw your attention to is the way the parts have been fabricated and what kind of remarkable results are possible with careful design, measurement, cutting, and finishing. Much of MDi #4 was made by hand-cutting and drilling sheets of high impact polystyrene (HIPS) with a utility knife and layering them as needed. Epoxy and aluminum provide gap filling and reinforcement of key sections, and fiberglass took care of one of the larger sections.

The process [Dickel] follows is to prototype using cardboard first. Parts are then designed carefully in CAD, and printed out at a 1:1 scale and glued to sheets of polystyrene. Each sheet is cut and drilled by hand as necessary. Layers are stacked and epoxied, embedding any hardware needed in the process. Two examples of embedding hardware include sealing captive nuts into parts with epoxy, or using aluminum to add reinforcement. After some careful sanding, the pieces look amazing.

Here’s something remarkably displeasant. Can you cook a steak with glue? [Dom] and [Chris] from ExplosiveDischarge have cooked a steak using a huge, huge amount of two-part epoxy. The chemistry behind this is just the exothermic reaction when two-part epoxy kicks off, and yes, the steak (a very thin cut) was sufficiently wrapped and protected from the hot sticky goo. What gas constant were the results? An overcooked steak, actually. This isn’t a sous vide setup where the temperature ramps up to 50°C and stays there — the temperature actually hit 80°C at its peak. There are a few ways to fix this, either by getting a thicker cut of steak, adding some bizarre water cooling setup to keep the temperature plateaued at a reasonable temperature.

We’ve got a twofer for awesome remote-controlled hovering stuff. The elektricity club first is a 1:8 scale Harrier. This plane designed and built by [Joel Vlashof] will be a reasonably accurate model of a Harrier, capable of VTOL. It’s built around a huge 130mm EDF, powered by 2x6s lipos, and stabilized with a kk2.1 flight controller with VTOL software. This is as accurate a Harrier that you’re going to get in such a small format, and has the cool little spinny vanes that allow the beast to transition from vertical to horizontal flight.

Want some more cool hovering things? [Tom Stanton] is building a remote controlled Chinook. Yes, that helicopter with two main rotors. The usual way of doing this is with proper helicopter control systems like collectives and Jesus nuts. [Tom]’s building this version with standard quadcopter technology, mounting a motor to a servo, and doubling it up, and mounting it on a frame. In effect, this RC Chinook is the tail boom of a tricopter doubled up on a single frame. It does fly, and he’s even built a neat foamboard body for it.

Here’s the stupidest thing you’re going to see all year. That’s someone looping a quadcopter in front of a Frontier A320 (Probably. Seems too big for a 319 and too small for a 321) on approach. This guy is 3.6 miles East of runway 25L at McCarran Internation in Las Vegas, at an altitude far above the 400-foot limit. Judging from the video and the wingspan, this quad came mafia 2 gas meter within 200 feet of a plane carrying at least 150 people. It’s the stupidest thing you’ve ever seen, so don’t do it. It’ll be great to see the guy responsible for this in jail. Posted in Hackaday Columns, Hackaday links Tagged Chinook, epoxy, harrier, jump jet, rc, remote controlled, two part epoxy