Small Engine Failure Leads To Impromptu Teardown

When the 6.5 HP (212 cc) Harbor Freight Predator engine in his kid’s go-kart gave up the ghost after some particularly hard driving, [HowToLou] figured it would be a good time to poke around inside the low-cost powerplant for our viewing pleasure. As a bonus, he even got it up and running again.

The shattered rod, and its replacement.

For an engine that has a retail price of just $160 USD, we’ve got to admit, the inside of the Predator doesn’t look too shabby. Admittedly, [HowToLou] determined that the cause of the failure was a blown connecting rod, but he also mentions that somebody had previously removed the engine’s governor, allowing it to rev up far beyond the nominal maximum of 3,600 RPM. No word on who snuck in there and yanked the governor out, but we’re betting it wasn’t the 7-year old driver…

Replacing the connecting rod meant taking most of the engine apart, but for our education, [HowToLou]  decided to take it a bit further and remove everything from the engine. After stripping it down to the block, he re-installs each piece while explaining its function. If you’ve ever wanted to see what makes one of these little engines tick, or perhaps you’ve got a Predator 212 cc in need of a repair or rebuild, the presentation is a fantastic resource.

Incidentally, this isn’t the first time we’ve seen the go-kart in question — back in June, we covered the unique electric reverse that [HowToLou] came up with for it.

DIY Prony Dyno Properly Displays Power Production

When hackers in the US think of a retailer called Harbor Freight, we usually think of cheap tools, workable but terrible DVM’s, zip ties, and tarps. [Jimbo] over at [Robot Cantina] looked at the 212cc “Predator” engine that they sell and thought “I bet I could power my Honda Insight with that.” And he did, successfully! How much power did the heavily modified engine make? In the video below the break, [Jimbo] takes us through the process of measuring its output using a home built dyno.

The dyno that [Jimbo] has built is a Prony Dyno, and it’s among the oldest and simplest designs available. A torque arm is extended from a disk brake caliper and connects to a force gauge. The engine is ran up to its highest speed, and then he brake is applied to the crankshaft until the engine almost stalls. A tachometer keep track of the RPM, and the force gauge measures the force on the torque arm. Torque is multiplied by RPM and the result is divided by a constant of 5252, and voilà: Horsepower. A computer plots the results across the entire range, and the dyno test is complete.

That only tells part of the story, and the real hack comes when you realize that the dyno stand, the force gauge setup and pretty much everything that can be built at home has been built at home. You’ll also enjoy seeing the results of some driving tests between the 212cc engine and its bigger 420cc brother, how even minor changes to the engine affect the horsepower and torque curves, and how that affects the Honda that he calls his “Street legal go cart.”

Speaking of unusual power plants, how about plant some hobby sized jet turbines on the back of your Tesla for fun?

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World’s Cheapest And Possibly Worst IR Camera

Don’t blame us for the title. [CCrome] admits it may well be the cheapest and worst IR camera available. The concept is surprisingly simple. Mount a cheap Harbor Freight non-contact thermometer on a 3D printer carriage and use it to scan the target. The design files are available on GitHub.

There is, of course, an Arduino to grab the data and send it to the PC. Some Python code takes care of converting it into an image.

Perhaps you don’t need a camera, but having a way to communicate with an $11 IR temperature sensor might come in handy someday. You do have to mash the measurement button down, so [CCrome] used the 3D printer to make a clamp for the button that also holds the POGO pins to the PCB. We would have been tempted to solder across the switch and also solder the wires to the pad. But, then again, you need a 3D printer for the project anyway.

Don’t expect the results you would get from a real thermal sensor. If you want that, you may have to build it yourself or open your wallet wide. If you need some inspiration for a use case, look at the thermal camera contest from a few years back.

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Hackaday Links: July 12, 2020

Based in the US as Hackaday is, it’s easy to overload the news with stories from home. That’s particularly true with dark tales of the expanding surveillance state, which seem to just get worse here on a daily basis. So we’re not exactly sure how we feel to share not one but two international stories of a dystopian bent; one the one hand, pleased that it’s not us for a change, but on the other, sad to see the trend toward less freedom and more monitoring spreading.

The first story comes from Mexico, where apparently everything our community does will soon be illegal. We couch that statement because the analysis is based on Google translations of reports from Mexico, possibly masking the linguistic nuances that undergird legislative prose. So we did some digging and it indeed appears that the Mexican Senate approved a package of reforms to existing federal copyright laws that will make it illegal to do things like installing a non-OEM operating system on a PC, or to use non-branded ink cartridges in a printer. Reverse engineering ROMs will be right out too, making any meaningful security research illegal. There appear to be exceptions to the law, but those are mostly to the benefit of the Mexican government for “national security purposes.” It’ll be a sad day indeed for Mexican hackers if this law is passed.

The other story comes from Germany, where a proposed law would grant sweeping surveillance powers to 19 state intelligence bodies. The law would require ISPs to install hardware in their data centers that would allow law enforcement to receive data and potentially modify it before sending it on to where it was supposed to go. So German Internet users can look forward to state-sponsored man-in-the-middle attacks and trojan injections if this thing passes.

OK, time for a palate cleanser: take an hour to watch a time-lapse of the last decade of activity of our star. NASA put the film together from data sent back by the Solar Dynamics Observatory, a satellite that has been keeping an eye on the Sun from geosynchronous orbit since 2010. Each frame of the film is one hour of solar activity, which may sound like it would be boring to watch, but it’s actually quite interesting and very relaxing. There are exciting moments, too, like enormous solar eruptions and the beautiful but somehow terrifying lunar transits. More terrifying still is a massive coronal mass ejection (CME) captured in June 2011. A more subtle but fascinating phenomenon is the gradual decrease in the number of sunspots over the decade as the Sun goes through its normal eleven-year cycle.

You’ll recall that as a public service to our more gear-headed readers that we recently covered the recall of automotive jack stands sold at Harbor Freight, purveyor of discount tools in the USA. Parts for the jack stands in question had been cast with a degraded mold, making the pawls liable to kick out under load and drop the vehicle, with potentially catastrophic results for anyone working beneath. To their credit, Harbor Freight responded immediately and replaced tons of stands with a new version. But now, Harbor Freight is forced to recall the replacement stands as well, due to a welding error. It’s an embarrassment, to be sure, but to make it as right as possible, Harbor Freight is now accepting any of their brand jack stands for refund or store credit.

And finally, if you thought that the experience of buying a new car couldn’t be any more miserable, wait till you have to pay to use the windshield wipers. Exaggeration? Perhaps only slightly, now that BMW “is planning to move some features of its new cars to a subscription model.” Plans like that are common enough as cars get increasingly complex infotainment systems, or with vehicles like Teslas which can be upgraded remotely. But BMW is actually planning on making options such as heated seats and adaptive cruise control available only by subscription — try it out for a month and if you like it, pay to keep them on for a year. It would aggravate us to no end knowing that the hardware supporting these features had already been installed and were just being held ransom by software. Sounds like a perfect job for a hacker — just not one in Mexico.

Planned Obsolescence Isn’t A Thing, But It Is Your Fault

The common belief is that big companies are out to get the little people by making products that break after a short period, or with substantially new features or accessories that make previous models obsolete, requiring the user to purchase a new model. This conspiracy theory isn’t true; there’s a perfectly good explanation for this phenomenon, and it was caused by the consumers, not the manufacturers.

When we buy the hottest, shiniest, smallest, and cheapest new thing we join the wave of consumer demand that is the cause of what often gets labelled as “Planned Obsolescence”. In truth, we’re all to blame for the signals our buying habits send to manufacturers. Dig in and get your flamewar fingers fired up.

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Failed Tool Turned Exploded Wall Art

Few things hit a hacker or maker harder than when a beloved tool goes to that Big Toolbox In The Sky. It can be hard to trash something that’s been with you through countless repairs and teardowns, made all the worse by the fact most employers don’t recognize “Tool Bereavement” as a valid reason to request time off. Maybe next time one of your trusty pieces of gear gives up the ghost, you can follow the example set by [usuallyplesent] and turn it into a piece of art to hang up on the shop wall.

The shop had gotten years of daily service out of this air powered angle die grinder (not bad for a $14 Harbor Freight tool), and he thought they should immortalize it in their waiting room by turning it into an interesting piece of art. After all, it’s not everyday that some folks see the insides of the sort of tools the more mechanically inclined of us may take for granted.

After taking the grinder apart and cleaning everything up, [usuallyplesent] decided to simplify things a bit by tossing out the assorted tiny components like seals and washers. By just focusing on the larger core components, the exploded view is cleaner and reminds us of a light saber cutaway.

Using a piece of scrap cardboard, [usuallyplesent] made templates for all of the major pieces of the grinder and used that to sketch out the placement and spacing on the white background. He then cut out each shape so the parts would be partially recessed into the board. This gives the effect that each piece was cut down the middle lengthwise but without all the hassle of actually cutting everything down the middle lengthwise.

We’ve previously seen similar displays made out of dissected consumer electronics, but there’s something rather personal about doing the same thing for a well-used tool. If any of our beloved readers feel inspired to enshrine a dead multimeter into a shadow box over the bench, be sure to let us know.

[via /r/justrolledintotheshop]

Automatic Dust Collection For The Whole Shop

If you’ve got a woodworking area, or even if you’ve just got something that really churns out dust like a belt sander or table saw, there’s an excellent chance you hate sawdust with a passion. It gets all over your clothes, jams up everything mechanical, and as a fun little bonus can be explosive if not handled properly. Thankfully newer tools tend to come with their own dust collection bags (back in the old days, you weren’t really a man unless you were coughing up wood fibers), but if you’ve got a half a dozen tools with half a dozen different dust bags you’ve got to empty, that can get pretty annoying.

Especially if you take woodworking as seriously as [Brad Wright] does. Over on his YouTube channel [DIY Builds], he quickly runs through the construction of a whole-shop dust collection system with some very neat features. Not everyone needs a system this intricate, but the tips and tricks he shows off during the build are great and can certainly be adapted to less grandiose setups.

Dust collection connector with closeable gate
One of the scratch-built gates.

[Brad] goes into a bit more detail in this gallery, revealing that the heart of the build is a Harbor Freight dust collection system that he modified into a cyclone separator. Big chunks fall down into the 55 gallon bucket, and what’s left gets blown out of the shop via a louvered vent through an exterior wall. An intricate system of 4 inch PVC pipe is then used to connect up each individual machine’s dust collection port. Even individual hand sanders get into the act via a three way manifold. His table saw lacked a dust port, so he enclosed the motor with a piece of plywood and made his own.

One of the most interesting aspects of the build is the scratch-built blast gates. These are essentially valves which open and close the different sections of the PVC where they mate to the individual stations. This prevents the dust collection system from wasting suction by trying to pull from all the stations at once when only one is in use at any given time. [Brad] even wired up the blast gates with switches that will turn the dust collection system on when the gate is open, and off when it’s closed.

This isn’t the first time we’ve covered the lengths people will go to rid their shop of dust. Cyclone dust separators are an especially popular build, using everything from sheet metal to 3D printed parts.

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