Welding Aluminum With A MIG Welder

October 29, 2022 by Al Williams 36 Comments

Steve Martin had a bit that was like a fake infomercial where he says, “You can be a millionaire and never pay taxes!” The instructions were, “First, get a million dollars. Then,…” [Brandon’s] instructions for how to convert your MIG welder to do aluminum for under $25 is not quite like that, but you do need the right kind of MIG welder to make it work. In particular, you need an actual MIG welder that has a provision to connect external gas. The instructions show a Hobart Handler 140 that meets the criteria and has sufficient power to handle aluminum.

The main task is to replace the liner for the torch. The stock liner is steel which is fine for its intended purpose, but it is too rough for aluminum wire. A PTFE liner is inexpensive and will work fine with the aluminum wire. If you want to do normal welding later, you’ll need to put the original liner back in.

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Two chillers side-by-side - the fake chiller on the left and the water fountain chiller (lid-less) on the right

Gutting And Upgrading Laser “Chiller” With No Chill

October 29, 2022 by Arya Voronova 10 Comments

Getting a cheap CO2 laser cutter is great for your workshop needs, and while you might get a weaker-than-declared laser tube, it’s still going to cut whatever you need to be cut. That might not be the case for the cooling equipment you’re getting alongside it, however, as [RealTimeKodi] shows in a post-project blogpost. They bought a CX3000 “chiller” and found out it had no chiller components (Nitter), only equipped with a radiator, a fan, and a pump.

Having your laser tube water be somewhat close to ambient temperature is something you can already achieve with an aquarium pump and a bucket of water — and it isn’t worth paying $100 for. Left with the sunk cost and an unfulfilled need for a proper chiller, [RealTimeKodi] started looking for paths to take – first one was using TEC elements. The upgrade process was fun, but the result was subpar, as the elements gobbled power with hardly any useful output to show for it.

[RealTimeKodi] didn’t give up, and eventually found an old water fountain chiller with chiller-like components inside, sold for $200. They could’ve used the water fountain as-is, but a few design issues and thirst for adventure got in the way, indisputably forcing them to stuff the fountain’s guts into the CX3000’s case.

Buying a laser cutter can sometimes feel like buying a 3D printer a decade ago — you get a K40, learn to use it, add the missing safety features, mod in autofocus, upgrade the control board, expand the work surface… That said, our experience shows that you don’t need any of those if A4-sized 3 mm wood cutting suit you, but a proper chiller is still worth its weight in gold-plated acrylic.

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Digital Kitchen Spoon Makes Weighing Your Ingredients A Snap

October 27, 2022 by Dan Maloney 14 Comments

There seem to be two camps when it comes to recipes: those based on volume-based measurements, and those based on the weight of ingredients. Gravimetric measurements have the advantage of better accuracy, but at the price of not being able to quickly scoop out a bit of this and a dash of that. It would be nice to get the convenience of volumetric measurements with the accuracy of weighing your ingredients, wouldn’t it?

It would, and that’s just what [Penguin DIY] did with this digital kitchen spoon scale. The build started with, perhaps not surprisingly, a large mixing spoon and a very small kitchen scale. The bowl of the spoon got lopped off the handle and attached to the strain gauge, which was removed from the scale along with its LCD display and circuit board. To hold everything, a somewhat stocky handle was fabricated from epoxy resin sandwiched between aluminum bolsters. Compartments for the original electronics parts, as well as a LiPo battery and USB charger module, were carved out of the resin block, and the electronics were mounted so that the display and controls are easily accessible. The video below shows the build as well as the spoon-scale in action in the kitchen.

We think this is not only a great idea but a fantastic execution. The black epoxy and aluminum look amazing together on the handle, almost like a commercial product. And sure, it would have been easy enough to build a scale from scratch — heck, you might even be able to do away with the strain gauge — but tearing apart an existing scale seems like the right move here.

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DIY Heat-Set Insert Press Says Complicated = Comfort

October 23, 2022 by Donald Papp 17 Comments

Heat-set inserts are a great way to embed mechanically-strong, threaded parts into a 3D print. For installation, all that is required is an economical soldering iron; something most of us already have.

The carriage and counterweight use a v-wheel gantry, GT2 belt, and other common hardware.

That’s fine for a handful of occasional inserts, but when a large number need to be inserted reliably and cleanly, something a little more refined is called for. That’s where [virchow]’s threaded insert press design comes in. It adds 3D-printed parts to an aluminum extrusion frame to create a press that smoothly lowers a soldering iron directly up and down, with minimal effort by the user.

The holder for the soldering iron is mounted to a small v-wheel gantry that rides along the vertical extrusion. The gantry features a counterweight to take care of resetting the position of the iron. [Virchow] admits that the design could be considered unnecessarily complicated (hence the “UC” in the name) but on the other hand, there’s nothing like doing a hundred or so inserts to make one appreciate every bit of comfort and stability.

Heat-set inserts aren’t difficult to use, but a little technique goes a long way. Spend a few minutes reading Joshua Vasquez’s guide on the optimal way to use them in 3D-printed parts to make sure yours not only go in straight but end up looking great as well.

Hackaday Prize 2022: Recycled Plastic Skateboard Decks Demonstrate Small-Scale Injection Molding

October 21, 2022 by Danie Conradie 25 Comments

Injection molding is usually focused on high-volume production, but that doesn’t always need to be the case. The Recycled Plastic Skateboard Deck project centers on the use of injection molding for a relatively low-volume production line using open-source tooling.

RPSD is part of the Precious Plastics ecosystem and uses the existing and open-source shredder and extruder to turn locally-sourced plastic waste into melted plastic. The core of the tooling is in the aluminum CNC-machined top, bottom, and edge mold sections bolted to a thick steel support structure that give the skateboard deck its shape. The edge section defines the deck’s perimeter, and 64 cartridge heaters are inserted into it to bring the mold up to temperature. The mold is mounted on a scissor lift mechanism to allow it to be aligned with the extruder, and temperature control electronics are housed in a laser-cut metal enclosure, which is bolted to the base of the mold structure.

To be clear, this is not a cheap way to make a couple of skateboard decks, but rather a way for small shops to do injection molded decks in-house. At ~$7500 for the components of this relatively large mold, excluding the extruder, you’d still have to sell quite a few decks to make it economically viable.

Although small-scale injection molding has become a lot more accessible, the cost of machined metal molds will remain high for the foreseeable future. However, if you only need small, flexible parts, you could probably do it for under $50 using 3D printed molds and silicone.

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A Homebrew AC Upgrade For The Fluke 8840A

October 20, 2022 by Lewin Day 9 Comments

[William Dudley] picked up a Fluke 8840A bench multimeter at an auction, but was sad to find out that it was reading resistances inaccurately. It was also missing the optional board to enable AC measurements. Desiring to use the otherwise lovely meter, he set about repairing and upgrading the device.

Thankfully, the 8840A was from a time when Fluke used to openly publish schematics in its manuals. Thus, combined with taking a look at some photos online, it was straightforward for [William] to recreate the original AC “Option 09” board to enable the desired functionality. As is usually the way, his efforts didn’t work first time, but after some bodge wires were installed, all was well. [William] reports the measurements are “reasonable, maybe even sufficient” with no calibration undertaken.

Repairing the resistance issue was easy. It turned out to be corrosion on the selector switches, revealed when high-resistance measurements were accurate, but low-resistance measurements weren’t. A bit of flick-flacker with some contact cleaner sprayed into the switches got things working again nicely.

It’s nice to see old hardware restored to full functionality, particularly when it’s as attractive and well-built as an old Fluke meter. Bringing back old tools from the dead? You know we wanna hear about it!

Rubber Stamping Your Way To Custom PCBs

October 19, 2022 by Lewin Day 22 Comments

Many of us now outsource PCB production to board houses overseas, which offer high-quality boards with increasingly impressive turnaround times. You might still brew up your own PCB, though, and a reader found this great old hack from [William Hare] that might be worth a look.

Forget toner transfer or marker pens — this build is all about speed. [William] decided to use a rubber stamp to quickly transfer ink to a copper board that can then be etched to produce a PCB. It’s simple and straightforward enough. We’ve used the same technique for silkscreen and pad art, but never as an etch resist.

The trick is to make several rubber stamps with different circuit elements, though. The genius part is that you can then assemble a PCB by simply stamping down the various circuit components you need. The boards will still need to be drilled if you’re working with through-hole parts, but tipster [Shri] notes that the technique is super useful for producing single-sided surface mount boards.

We’ve seen some other unique methods to producing PCBs at home, such as using a 3D printer to help out. If you’ve got your own innovative homebrew PCB hacks, be sure to drop us a line!

Thanks [Shri Hari Ram] for the tip!