Testing Whether Heated Chambers Help Brittle Filaments

March 17, 2026 by Maya Posch 7 Comments

Some FDM filaments are pretty brittle even if properly dried and stored, especially those which contain carbon fiber (CF) or similar additives like glass fiber (GF). This poses a problem in that these filaments can snap even within the PTFE tube as they’re being guided towards the extruder. Here a community theory is that having an actively heated chamber can help prevent this scenario, but is it actually true? [Dr. Igor Gaspar] of the My Tech Fun YouTube channel gave this myth a try to either confirm or bust it.

The comments suggested that heating the chamber to 65°C will help, but there’s little information online to support this theorem. To test the claim, a heated chamber was used along with a bending rig to see at which angle the filament would snap. In total five different filaments from three manufacturers (Polymaker, Qidi and YXPolyer) were tested, including Qidi’s PET-GF and PAHT-GF as the sole non-CF filaments.

A big question is how long exactly the filament will spend inside the heated chamber after making its way from the spool, which would be about 2.5 minutes with a 500 mm tube. For the test 5 minutes was used for the best possible result. Despite this, the results show that even with the standard deviation kept in mind, the heating actually seems to make the filaments even more brittle.

Considering that in general CF seems to simply weaken the polymer matrix after printing, this finding adds to the question of whether these CF and GF-infused filaments make any sense at all.

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How To Grow Large Sugar Crystals

March 17, 2026 by Maya Posch 9 Comments

Many substances display crystallization, allowing them to keep adding to a basic shape to reach pretty humongous proportions. Although we usually tend to think of pretty stones that get fashioned into jewelry or put up for display, sugar also crystallizes and thus you can create pretty large sugar crystals. How to do this is demonstrated by [Chase] of Crystalverse fame in a recent video.

This is effectively a follow-up to a 2022 blog article in which [Chase] showed a few ways to create pretty table sugar (sucrose) based crystals. In that article the growth of single sucrose crystals was attempted, but a few additional crystals got stuck to the main crystal so that it technically wasn’t a single crystal any more.

With this new method coarse sugar is used both for seed crystals as well as for creating the syrupy liquid from mixing 100 mL of water with 225 grams of sugar. Starting a single crystal is attempted by using thin fishing wire in a small vessel with the syrup and some seed crystals, hoping that a crystal will lodge to said fishing wire.

After a few attempts this works and from there the crystals can be suspended in the large jar with syrup to let them continue growing. It’s important to cover the jar during this period, as more crystals will form in the syrup over time, requiring occasional removal of these stray ones.

Naturally this process takes a while, with a solid week required to get a sizeable crystal as in the video. After this the crystal is effectively just a very large version of the sugar crystals in that 1 kg bag from the supermarket, ergo it will dissolve again just as easily. If you want a more durable crystal that’s equally easy to grow, you can toss some vinegar and scrap copper together to create very pretty, albeit toxic, copper(II) acetate crystals.

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Testing A Soviet 1000 Volt Insulation Tester From 1985

March 17, 2026 by Maya Posch 8 Comments

Although the term ‘Iron Curtain’ from the Cold War brings to mind something like the Berlin Wall and its forbidding No Man’s Land, there was still active trade between the Soviet Union and the West. This included devices like the M4100/4 insulation tester that the [Three-phase] YouTube channel recently looked at, after previously poking at a 1967 USSR resistance bridge.

This particular unit dates to 1985, and comes in a rather nice-looking case that somewhat looks like bakelite. It’s rated for up to 1 gigaohm, putting out 1,000 V by using the crank handle. Because of the pristine condition of the entire unit, including seals, it was decided to not look at the internals but only test its functionality.

After running through the basic usage of the insulation tester it’s hooked up to a range of testing devices, which shows that it seems to be mostly still in working condition. The first issue noticed was that the crank handle-based generator was a bit tired, so that it never quite hit the maximum voltage.

With no parallax correction and no known last calibration date, it still measured to about 10% of the actual value in some tests initially, but in later tests it was significantly off from the expected value. At this point the device was suspected of being faulty, but it defied being easily opened, so any repair will have to be put off for now. That said, it being in such good condition raises the prospect of it being an easy repair, hopefully in an upcoming video.

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Preparing To Fire Up A 90-Year-Old Boiler After Half A Century

March 17, 2026 by Maya Posch 3 Comments

Continuing the restoration of the #1 Lancashire boiler at the Claymills Pumping Station in the UK, the volunteers are putting on the final touches after previously passing the boiler inspection. Although it may seem that things are basically ready to start laying down a fire after the boiler is proven to hold 120 PSI with all safeties fully operating, they first had to reassemble the surrounding brickwork, free up a seized damper shaft and give a lot of TLC to mechanisms that were brand new in the 1930s and last operated in 1971.

Removing the ashes from a Lancashire boiler. (Credit: Claymills pumping station, YouTube)

The damper shaft is part of the damper mechanism which controls doors that affect the burn rate, acting as a kind of throttle for the boilers. Unfortunately the shaft’s bearings had seized up completely, and no amount of heat and kinetic maintenance could loosen it up again. This forced them to pull it out and manufacture a replacement, but did provide a good look at how it’s put together. The original dial indicator was salvaged, along with some other bits that were still good.

Next was to fit the cast-iron ash boxes that sit below the boiler and from where ash can be scraped out and deposited into wheelbarrows. The automatic sprinkler stokers are fitted above these, with a good look at their mechanism. The operator is given a lot of control over how much coal is being fed into the boiler, as part of the early 20th-century automation.

The missing furnace doors on the #1 boiler were replaced with replicas based on the ones from the other boilers, and some piping around the boiler was refurbished. Even after all that work, it’ll still take a few weeks and a lot more work to fully reassemble the boiler, showing just how complex these systems are. With some luck it’ll fire right back up after fifty years of slumbering and decades of suffering the elements.

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From 8086 To Z80: Building A NASM-Inspired SDK For 8-Bit Retro Computing

March 17, 2026 by Maya Posch 4 Comments

Assembler syntax is a touchy subject, with many a flamewar having raged over e.g. Intel vs AT&T style syntax. Thus when [Humberto Costa] recently acquired an MSX system for some fun retro-style ASM programming, he was dismayed to see that the available Z80 assemblers did not support the syntax of his favorite ASM tool, NASM. Thus was born the HC SDK project, which seeks to bring more NASM to the Z80, 8085 and a slew of other processors.

There’s both a project site and a GitHub repository, from where both source and pre-compiled releases can be obtained. Supported host platforms are macOS, Windows, OpenBSD, FreeBSD, and Linux, with currently supported targets the 8080, 8085, 8086 and Z80. Support for the 6502 is currently in progress.

The Netwide Assembler (NASM), targets only the x86 architecture, being one of the most popular assemblers for Linux and x86. It uses a variant of the Intel ASM syntax, which contrasts it strongly with the GNU Assembler (GAS) that uses AT&T syntax. Of course, in an ironic twist of fate NASM now also supports AT&T syntax and vice versa, albeit with some subtle gotchas.

Regardless, if ASM for these retro architectures is your thing, then the HC SDK may be worth checking out. [Humberto] also says that he’s looking at adding higher-level language support to make it a more complete development environment for these old systems and new takes on them.

Thanks to [Albert Wolf] for the tip.

Recycled Plastic Compression Molding With 3D-Printed Molds

March 16, 2026 by Maya Posch 10 Comments

Recycling plastic at home using 3D printed molds is relatively accessible these days, but if you do not wish to invest a lot of money into specialized equipment, what’s the most minimal setup that you can get away with? In a recent [future things] video DIY plastic recycling is explored using only equipment that the average home is likely to have around.

Lest anyone complain, you should always wear PPE such as gloves and a suitable respirator whenever you’re dealing with hot plastic in this manner, just to avoid a trip to the emergency room. Once that issue is taken care of, there are a few ways of doing molding, with compression molding being one of the most straightforward types.

With compression molding you take two halves of a mold, and one half compresses the material inside the other half. This means that you do not require any complex devices like with injection molding: just a toaster oven or equivalent to melt the plastic, which is LDPE in this example. The scrap plastic is placed in a silicone cup before it’s heated so that it doesn’t stick to the container.

The wad of goopy plastic is then put inside the bottom part of the mold before the top part is put in place and squeezed by hand until molten plastic comes out of the overflow opening(s). After letting it fully cool down, the mold is opened and the part released. Although the demonstrated process can be improved upon, it seems to work well enough if you are aware of the limitations. In terms of costs and parts required it’s definitely hard to come up with a cheaper way to do plastic molding.

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Making A Better Kitchen Scale Out Of Junk Parts

March 16, 2026 by Maya Posch 10 Comments

Kitchen scales are plentiful and cheap, but their accuracy and measuring speed often leave a lot to be desired. In particular the filtering out of noise can make small changes a nightmare because adding a little bit of weight slowly can result in the result never updating. This frustrated [Mark Furneaux] enough that he dug up the load cell and metal base of a scrapped laboratory scale and added a strain gauge amplifier to build a better kitchen scale around it.

The only purpose-bought part was an HX710-based strain gauge amplifier module for $7 with LED display, with the metal base getting some metal bits welded onto it to hold said module as well as a push button and toggle switch. Existing wiring from the load cell was wired into the HX710 module, with power provided from a single 18650 Li-ion cell. This was paired with the standard TP4056-based module and its protection IC.

Ultimately the entire assembly looks very much bodged together, with plentiful zip ties, hot glue and messy welding, but it’s hard to deny that it seems to work well. A plastic cutting board makes for a good surface for the items being weighed, and measured drift across the range was about 200 mg, while the amplifier module updates the output in real-time so that you can see even the smallest changes and noise.

Even if you’re not lucky enough to have such a nice load cell and base kicking around, strain gauges are everywhere, and you can absolutely hack an existing (kitchen) scale to be better with some custom hard- and software.

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