Grind Your Welds With Pride, If That’s The Way You Do It

October 22, 2019 by Jenny List 84 Comments

To grind or not to grind? What a question! It all depends on what you’re really trying to show, and in the case of welded joints, I often want to prove the integrity of the weld.

My ground-back piece of welded tube. Eagle-eyed readers will spot that the grinding reveals a weld that isn't perfect. — My ground-back piece of welded tube. Eagle-eyed readers will spot that the grinding reveals a weld that isn’t perfect.

Recently, I wrote a piece in which I talked about my cheap inverter welder and others like it. As part of it I did a lower-current weld on a piece of thin tube and before snapping a picture of the weld I ground it back flat. It turns out that some people prefer to see a picture of the weld bead instead — the neatness of the external appearance of the weld — to allow judgment on its quality. Oddly I believe the exact opposite, that the quality of my weld can only be judged by a closer look inside it, and it’s this point I’d like to explore.

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Solve Your Precision Woes With A Sliding Angle Grinder

October 3, 2019 by Sharon Lin 9 Comments

Angle grinders are among the most useful tools for anyone who’s ever had to cut metal. They’re ergonomic, compact, and get the job done. Unfortunately, one of the tradeoffs you usually make when using them is precision.

But thankfully, there’s a DIY solution. YouTuber [workshop from scratch] demonstrated the build process for a sliding angle grinder in a recent video, welding steel beams into a flat frame and attaching fitted beams on top to slide across the rows. Where necessary, spacers are used to ensure that the slider is perfectly fitted to the beam. The contraption holding the angle grinder – a welded piece of steel bolted to the sliding mechanism – has a grip for the user to seamlessly slide the tool across the table.

The operation is like a more versatile and robust chop saw, not to mention the customized angle references you can make to cut virtually anything you like. The build video shows the entire process, from drill pressing and turning holes to welding pieces of the frame together to artfully spray painting the surface a classy black, with familiarity enough to make the project look like a piece of cake.

As the name implies, [workshop from scratch] is all about building your own shop tools, and we’ve previously taken a look at their impressive hydraulic vise and mobile crane builds. These tools, largely hacked together from scraps, prove that setting up your own shop doesn’t necessarily mean you need to break the bank.

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Bend Some Bars With A Flywheel

September 25, 2019 by Danie Conradie 16 Comments

The ability to look at a pile of trash, and see the for treasure is a skill we hold in high regard around here. [Meanwhile in the Garage] apparently has this skill in spades and built himself a metal bar bending machine using an old flywheel and starter pinion gear.

To bend metal using muscle power alone requires some sort of mechanical advantage. Usually this involves a bending tool with a long lever, but [Meanwhile in the Garage] decided to make use of the large gear ratio between a car’s starter motor and the flywheel it drives. This does away with the need for a long lever and allows bending to almost 270° with a larger radius. Lathe and milling work features quite prominently, including to make the bend formers, drive shaft and bushings and to modify the flywheel to include a clamp. The belt sander that is used to finish a number of the parts is also his creation. While the machine tools definitely helped, a large amount of creativity and thinking outside the box made this project possible and worth the watch.

We’ve featured a number of scrap-built tools including a milling machine, sheet metal hole punch and a hydraulic bench vice. Keep them coming!

Modified Tombstone Welder Contains A Host Of Hacks

September 12, 2019 by Dan Maloney 30 Comments

State-of-the-art welding machines aren’t cheap, and for good reason: pushing around that much current in a controlled way and doing it over an entire workday takes some heavy-duty parts. There are bargains to be found, though, especially in the most basic of machines: AC stick welders. The familiar and aptly named “tombstone” welders can do the business, and they’re a great tool to learn how to lay a bead.

Tombstones are not without their drawbacks, though, and while others might buy a different welder when bumping up against those limits, [Greg Hildstrom] decided to hack his AC stick welder into an AC/DC welder with TIG. He details the panoply of mods he made to the welder, from a new 50 A cordset made from three extension cords where all three 12 gauge wires in each cord are connected together to make much larger effective conductors, to adding rectifiers and a choke made from the frame of a microwave oven transformer to produce DC output at the full 225 A rating. By the end of the project the tombstone was chock full of hacks, including a homemade foot pedal for voltage control, new industry-standard connectors for everything, and with the help of a vintage Lincoln “Hi-Freq” controller, support for TIG, or tungsten inert gas welding. His blog post shows some of the many test beads he’s put down with the machine, and the video playlist linked below shows highlights of the build.

This isn’t [Greg]’s first foray into the world of hot metal. A few years back we covered his electric arc furnace build, powered by another, more capable welder.

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Rideable Tank Tread: It’s A Monotrack Motorcycle That Begs You To Stop Very Slowly

September 11, 2019 by Danie Conradie 47 Comments

There will always be those of us who yearn for an iron steed and the wind through your hair. (Or over your helmet, if you value the contents of your skull.) If having fun and turning heads is more important to you than speed or practicality, [Make it Extreme] has just the bike for you. Using mostly scrapyard parts, they built a monotrack motorcycle — no wheels, just a single rubber track.

[Make it Extreme] are definitely not newcomers to building crazy contraptions, and as usual the entire design and build is a series of ingenious hacks complimented by some impressive fabrication skills. The track is simply a car tyre with the sidewalls cut away. It fits over a steel frame that can be adjusted to tension the track over a drive wheel and a series of rollers which are all part of the suspension system.

Power is provided by a 2-stroke 100cc scooter engine, and transmitted to the track through a drive wheel made from an old scuba tank. What puts this build over the top is that all of this is neatly located inside the circumference of the track. Only the seat, handlebars and fuel tank are on the outside of the track. The foot pegs are as far forward as possible, which helps keep your center of gravity when stopping. It’s not nearly as bad as those self-balancing electric monocycles, but planning stops well in advance is advisable.

While it’s by no means the fastest bike out there it definitely looks like a ton of fun. Build plans are available to patrons of [Make it Extreme], but good luck licensing one as your daily driver. If that’s your goal, you might want to consider adding a cover over the track between the seat and handlebars to prevent your khakis from getting caught on your way to the cubicle farm.

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Fail Of The Week: Supercapacitor Spot Welder

August 15, 2019 by Al Williams 33 Comments

[Julian] needed to weld a bit of nickel to some steel and decided to use a spot welding technique. Of course he didn’t have a spot welder sitting around. Since these are fairly simple machines so [Julian] set out to build a spot welder using a charged supercapacitor. The fundamentals all seem to be there — the supercap is a 100 Farad unit and with a charge of 2.6V, that works out to over 300 joules — yet it simply doesn’t work.

The problem is in how the discharge energy is being directed. Just using the capacitor would cause the charge to flow out as a spark when you got near the point to discharge. To combat this, [Julian] put a microswitch between the capacitor and the copper point he expected to use as the welding tip. The microswitch, of course, is probably not the best for carrying a large surge of current, so we suspect that may be part of why he didn’t get great results.

The other thing we noticed is that he used a single point and used the workpiece as a ground return. Most spot welders use two points near each other or on each side of the workpiece. The current from the capacitor is probably just absorbed by the relatively large piece of metal.

The second video below from [American Tech] shows a 500F capacitor doing spot welding with little more than two wires and it seems to work. Hackaday’s own [Sean Boyce] even made one out of some whopping 3000F caps. It did work, although he’s been pursuing improvements.

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Russian EBike Goes Everywhere, Possibly Legal

July 28, 2019 by Bryan Cockfield 54 Comments

Electric bikes may be taking the world by storm, but the world itself doesn’t have a single way of regulating ebikes’ use on public roads. Whether or not your ebike is legal to ride on the street or sidewalk where you live depends mostly on… where you live. If you’re lucky enough to live in a place where a bicycle is legally defined as having fewer than four wheels and capable of being powered by a human, though, this interesting bike from Russia might be the best homemade ebike we’ve ever seen. (Video embedded below the break.)

While some of the details of this build might be lost on those of us who do not know any Slavic languages, the video itself shows off the features of this electric vehicle build quite well. It has a custom built frame with two wheels up front, each with its own independent suspension, allowing it to traverse extremely rough terrain with ease even a mountain bike might not be able to achieve. It seems to be powered by a relatively simple rear hub in the single rear wheel, and can probably achieve speeds in the 20 km/h range while holding one passenger and possibly some cargo.

The impressive part of this build isn’t so much the electrification, but rather the suspension components. Anyone looking for an offroad vehicle may be able to take a bit of inspiration from this build. If you’re more interested in the drivetrain, there are plenty of other vehicles that use unique electric drivetrains to check out like this electric boat. And, if you happen to know Russian and see some other interesting details in this build that the native English speakers around here may have missed, leave them in the comments for us.

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