Printing With Metal On The Ender 3 Using Only A Friction Wheel

December 24, 2025 by Maya Posch 5 Comments

Printing metal as easily as it is to printed with thermoplastics has been a dream for a very long time, with options for hobbyists being very scarce. This is something which [Rotoforge] seeks to change, using little more than an old Ender 3 FDM printer and some ingenuity. Best of all is that the approach on which they have been working for the past year does not require high temperature, molten metals and no fussing about with powdered metal.

Additive manufacturing using friction welding. (Credit: Ruishan Xie, et al., j.mtcomm, 2021)

Rather than an extruder that melts a thermoplastic filament, their setup uses metal wire that is fed into a friction welding tool head, the details of which are covered in the video as well as on the GitHub project page. Unlike their previous setup which we reported on last year, this new setup is both safer and much riskier. While there’s no more molten metal, instead a very loud and very fast spinning disk is used to provide the friction required for friction welding, specifically friction and rolling-based additive manufacturing (FRAM) as in the cited 2021 paper by [Ruishan Xie] et al. in Materials Today Communications. By the same lead author there’s also a 2025 paper that explores more complex implementations of FRAM.

Continue reading “Printing With Metal On The Ender 3 Using Only A Friction Wheel” →

A browser window is shown, in which a web page is displaying a green trace of a square wave.

A Compact, Browser-Based ESP32 Oscilloscope

December 21, 2025 by Aaron Beckendorf 33 Comments

An oscilloscope is usually the most sensitive, and arguably most versatile, tool on a hacker’s workbench, often taking billions of samples per second to produce an accurate and informative representation of a signal. This vast processing power, however, often goes well beyond the needs of the signals in question, at which point it makes sense to use a less powerful and expensive device, such as [MatAtBread]’s ESP32 oscilloscope.

Continue reading “A Compact, Browser-Based ESP32 Oscilloscope” →

The Lethal Danger Of Combining Welding And Brake Cleaner

December 17, 2025 by Maya Posch 52 Comments

With the availability of increasingly cheaper equipment, welding has become far more accessible these days. While this is definitely a plus, it also comes with the elephant-sized asterisk that as with any tool you absolutely must take into account basic safety precautions for yourself and others. This extends to the way you prepare metal for welding, with [Dr. Bernard], AKA [ChubbyEmu] recently joining forces with [styropyro] to highlight the risks of cleaning metal with brake cleaner prior to welding.

Much like with common household chemicals used for cleaning, such as bleach and ammonia, improper use of these can produce e.g. chlorine gas, which while harmful is generally not lethal. Things get much more serious with brake cleaner, containing tetrachloroethylene. As explained in the video, getting brake cleaner on a rusty part to clean it and then exposing it to the intensive energies of the welding process suffices to create phosgene.

Continue reading “The Lethal Danger Of Combining Welding And Brake Cleaner” →

3D Printing And Metal Casting Are A Great Match

December 15, 2025 by Donald Papp 23 Comments

[Chris Borge] has made (and revised) many of his own tools using a combination of 3D printing and common hardware, and recently decided to try metal casting. Having created his own tapping arm, he tries his hand at aluminum casting to create a much more compact version out of metal. His video (embedded below) really shows off the whole process, and [Chris] freely shares his learning experiences in casting his first metal tool.

The result looks great and is considerably smaller in stature than the 3D-printed version. However, the workflow of casting metal parts is very different. The parts are much stronger, but there is a lot of preparation and post-processing involved.

Metal casting deals with molten metal, but the process is otherwise very accessible, and many resources are available to help anyone with a healthy interest.

The key to making good castings is mold preparation. [Chris] uses green sand (a mixture of fine sand and bentonite clay – one source of the latter is ground-up kitty litter) packed tightly around 3D printed parts inside a frame. The packed sand holds its shape while still allowing the original forms to be removed and channels to be cut, creating a two-part mold.

His first-time castings have a rough surface texture, but are perfectly serviceable. After some CNC operations to smooth some faces and drill some holes, the surface imperfections are nothing filing, filler, and paint can’t handle.

To cast molten metal, there really isn’t any way around needing a forge. Or is there? We have seen some enterprising hackers repurpose microwave ovens for this purpose. One can also use a low-temperature alloy like Rose’s Metal, or eschew molten liquid altogether and do cold casting, which uses a mixture of resin and metal powder instead.

The design files for [Chris]’s tapping arm are available from links in the video description, and he also helpfully provides links to videos and resources he found useful. Watch it in the video, embedded just below.

Continue reading “3D Printing And Metal Casting Are A Great Match” →

Cheap 10x10cm Hotplate Punches Above Its Weight

December 10, 2025 by Arya Voronova 14 Comments

For less than $30 USD, you can get a 10×10 centimeter hotplate with 350 Watts of power. Sounds mighty fine to us, so surely there must be a catch? Maybe not, as [Stefan Nikolaj]’s review of this AliExpress hotplate details, it seems to be just fine enough.

At this price, you’d expect some shoddy electronics inside, or maybe outright fiery design decisions, in the vein of other reviews for similar cheap heat-producing tech that we’ve seen over the years. Nope – the control circuitry seems to be more than well-built for our standards, with isolation and separation where it matters, the input being fused away, and the chassis firmly earthed. [Stefan] highlights just two possible problem areas: a wire nut that could potentially be dodgy, and lack of a thermal fuse. Both can be remedied easily enough after you get one of these, and for the price, it’s a no-brainer. Apart from the review, there’s also general usage recommendations from [Stefan] in the end of the blog post.

While we’re happy to see folks designing their own PCB hotplates or modifying old waffle irons, the availability of cheap turn-key options like this means there’s less of a reason to go the DIY route. Now, if you’re in the market for even more build volume, you can get one of the classic reflow ovens, and maybe do a controller upgrade while you’re at it.

Sudo Clean Up My Workbench

December 6, 2025 by Al Williams 20 Comments

[Engineezy] might have been watching a 3D printer move when inspiration struck: Why not build a robot arm to clean up his workbench? Why not, indeed? Well, all you need is a 17-foot-long X-axis and a gripper mechanism that can pick up any strange thing that happens to be on the bench.

Like any good project, he did it step by step. Mounting a 17-foot linear rail on an accurately machined backplate required professional CNC assistance. He was shooting for a 1mm accuracy, but decided to settle for 10mm.

Continue reading “Sudo Clean Up My Workbench” →

Preventing A Mess With The Weller WDC Solder Containment Pocket

December 4, 2025 by Maya Posch 30 Comments

Have you ever tipped all the stray bits of solder out of your tip cleaner by mistake? [MisterHW] is here with a bit of paraffin wax to save the day.

Hand soldering can be a messy business, especially when you wipe the soldering iron tip on those common brass wool bundles that have largely come to replace moist sponges. The Weller Dry Cleaner (WDC) is one of such holders for brass wool, but the large tray in front of the opening with the brass wool has confused many as to its exact purposes. In short, it’s there so that you can slap the iron against the side to flick contaminants and excess solder off the tip.

Along with catching some of the bits of mostly solder that fly off during cleaning in the brass wool section, quite a lot of debris can be collected this way. Yet as many can attest to, it’s quite easy to flip over brass wool holders and have these bits go flying everywhere.

That’s where [MisterHW]’s pit of particulate holding comes into play, using folded sheet metal and some wax (e.g. paraffin) to create a trap that serves to catch any debris that enters it and smother it in the wax. To reset the trap, simply heat it up with e.g. the iron and you’ll regain a nice fresh surface to capture the next batch of crud.

As the wax is cold when in use, even if you were to tip the holder over, it should not go careening all over your ESD-safe work surface and any parts on it, and the wax can be filtered if needed to remove the particulates. When using leaded solder alloys, this setup also helps to prevent lead-contamination of the area and generally eases clean-up as bumping or tipping a soldering iron stand no longer means weeks, months or years of accumulations scooting off everywhere.