A Battery-Tab Welder With Real Control Issues

September 16, 2017 by Dan Maloney 56 Comments

Spot welding should easier than it looks. After all, it’s just a lot of current in a short time through a small space. But it’s the control that can make the difference between consistently high-quality welds and poor performance, or maybe even a fire.

Control is where [WeAreTheWatt]’s next-level battery tab spot welder shines. The fact that there’s not a microwave oven transformer to be seen is a benefit to anyone sheepish about the usual mains-powered spot welders we usually see, even those designed with safety in mind. [WeAreTheWatt] chose to power his spot welder from a high-capacity RC battery pack, but we’d bet just about any high-current source would do. The controller itself is a very sturdy looking PCB with wide traces and nicely machined brass buss bars backing up an array of MOSFETs. A microcontroller performs quite a few functions; aside from timing the pulse, it can control the energy delivered, read the resistance of the 8AWG leads for calibration purposes, and even detect bad welds. The welder normally runs off a foot switch, but it can also detect when the leads are shorted and automatically apply a pulse — perfect for high-volume production. See it in action below.

There may be bigger welders, and ones with a little more fit and finish, but this one looks like a nicely engineered solution.

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A Fix For The Lightweight Machine Tool Shakes

September 16, 2017 by Dan Maloney 12 Comments

No matter what material you work with, the general rule is that with machine tools, the heavier, the better. Some people can’t afford or don’t want big tools, though, even with their natural tendency to reduce vibrations. That doesn’t mean something can’t be done to help the little tools, like reducing vibration in a contractor-grade table saw.

This one might seem a little outside the usual confines of the hackosphere, but nobody can doubt [Matthias Wandel]’s hacker chops and he really shows off his problem-solving skills with this one. His well-worn contractor-style table saw has had more than a few special modifications over the years, some of which left it with a shimmy sufficient to vibrate workpieces right off the table. He fashioned a friction damper for the saw’s motor from wood, complete with ball and socket joints to allow full movement of the blade height and angle. That didn’t quite do the trick, but his incremental approach finally found the right combination of factors, and the video below shows a saw now stable enough to balance a nickel.

If the name seems familiar but you just can’t place the hacks, check out [Matthias]’s recent wooden domino extruder, his shortcuts to tapping wood, or of course his classic wood gears layout software.

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Cutting Stone With A Diamond Bit Built From Plumbing Parts

September 15, 2017 by Adam Fabio 24 Comments

Everyone’s favorite Canadian is at it again. This time, [AVE] needed to cut a large hole in a stone countertop. They making coring bits for this, but a bit this size would cost upwards of $400. Not a problem. [AvE] broke out the tools and built his own stone cutting bit.

Everything starts with a 6″ plastic pipe cap. [AvE] center drilled the cap, then threaded it. A turned down bolt makes a great arbor for this new tool. The edge of the cap was then slotted. [AvE] used a clapped out Bridgeport milling machine, but you could do the same job with a hacksaw or a Dremel tool.

The secret sauce is industrial diamonds. That’s right, this is a diamond cutting bit. [AvE] ordered 20 grams of 20-25 mesh industrial diamonds. “Mesh” defines the size of the individual diamonds — in this case around 50 microns and up. Now, how to bind diamond and plastic? Plumber’s transition cement didn’t work – the diamonds and coating just peeled off like a sunburn. The solution turned out to be JB-Weld. A liberal coating of JB-Weld on the face of the tool, a sprinkling of industrial diamonds, and the pipe cap was ready to cut.

The cutting operation was slow, steady, and lots of cooling water. [AvE] made it most of the way through his countertop before having to refurbish his bit.

[AvE] usually is a man of many words, as can be seen in this post about his EDM machine. This time though, he gave us the silent treatment — an entire video with no words, set to classical music. It’s great seeing YouTubers step outside their comfort zone and trying something new.

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Think You Know Everything About Soldering?

September 12, 2017 by Al Williams 50 Comments

[Joshua] has frequent discussions about his soldering techniques with viewers of his YouTube channel. He finally decided to interview [Randy Rubinstein] who is the president of SRA Soldering. In nearly an hour, they talk about everything from solder alloys to proper temperature. They also talk about lead exposure, flux cleaning, and lead-free solder.

They also talk about strategies for rework with lead-free and using special solder for removing SMD components. Honestly, although the first frame of the video says “your solder sucks,” we didn’t really find any earth-shattering revelations about something everyone’s doing wrong. We did, however, find a lot of good advice and some interesting details about things like the uses for different solder alloys.

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Hakko FX-901: Better Than TS-100?

September 12, 2017 by Al Williams 45 Comments

You’ve surely seen the TS-100 soldering iron. It has an OLED display, an ARM processor, and will run with an external battery pack. They are not too pricey, but at $80 or so they aren’t exactly an impulse buy, either. [Drone Camps RC] used one in the field and decided to try a Hakko FX-901 instead. He did a video review that you can see below.

The FX-901 is about half the price of a TS-100. Granted, it doesn’t have a fancy display and you can’t hack it to play Tetris. However, it does take batteries (including rechargeable) without an external pack. The manufacturer claims up to two hours of use and that it will melt solder in 40 seconds. From the video, the iron actually melted solder in under 30 seconds. The two hours, by the way, is with rechargeables. Alkaline AA batteries should give about 70 minutes of operation.

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Things Learned From Hot Wire Cutting A Droid’s Body

September 9, 2017 by Donald Papp 8 Comments

One of [Bithead]’s passions is making Star Wars droids, and in the process of building the outer shell for one of them he decided to use hot wire foam cutting and make his own tools. Having the necessary parts on hand and having seen some YouTube videos demonstrating the technique, [Bithead] dove right in. Things didn’t go exactly to plan but happily he decided to share what did and didn’t work, and in the end the results were serviceable.

[Bithead] built two hot wire cutters with nichrome wire. The first was small, but the second was larger and incorporated some design refinements. He also got an important safety reminder when he first powered on with his power supply turned up too high; the wire instantly turned red and snapped with an audible bang. He belatedly realized he was foolishly wearing neither gloves nor eye protection.

When it came to use his self-made tools, one of the biggest discoveries was that not all foam is equal in the eyes of a hot wire cutter. This is one of those things that’s common knowledge to experienced people, but isn’t necessarily obvious to a newcomer. A hot wire cutter that made clean and effortless cuts in styrofoam did no such thing with the foam he was using to cast his droid’s outer shell. Still, he powered through it and got serviceable results. [Bithead]’s blog post may not have anything new to people who have worked with foam and hot wire cutters before, but if you’re new to such things you can use it to learn from his experiences. And speaking of improving experiences, [Bithead] most recently snazzed up the presentation of his R2-D2 build by getting tricky with how he hides his remote control.

Modding A Powdercoating Gun For Performance

September 9, 2017 by Lewin Day 6 Comments

In life, tools come in two varieties – good tools, and cheap tools. This is where the hacker steps in, to transform a cheap tool into more than the sum of its parts. [Josh] had problems with his Eastwood powdercoating gun. [Josh] decided to fix things with a couple of tasteful mods.

The problem with the gun was related to the delivery of powder to the workpiece. The stream was either too weak to coat properly, or too heavy, delivering a thick stream of powder. [Josh] surmised that with better airflow into the powder reservoir, the gun would deliver a properly mixed cloud of powder as required. By drilling a couple of small holes into the air feed into the reservoir, the powder stream was much less heavy and the gun’s performance was greatly improved.

[Josh] then decided to take things a step further, by fitting a tip from a more expensive gun to his Eastwood model. There were some challenges in getting it connected electrically, but nothing a little electrical tape couldn’t fix. While this did further improve results, it was a minor improvement compared to the air feed modifications.

Overall, [Josh] was able to take a poorly performing tool and transform it into something much more useful, just by drilling a couple of holes. Check out our Hacklet on quick tool hacks, or share your best work in the comments.