Field Guide To The North American Weigh Station

June 26, 2025 by Dan Maloney 39 Comments

A lot of people complain that driving across the United States is boring. Having done the coast-to-coast trip seven times now, I can’t agree. Sure, the stretches through the Corn Belt get a little monotonous, but for someone like me who wants to know how everything works, even endless agriculture is fascinating; I love me some center-pivot irrigation.

One thing that has always attracted my attention while on these long road trips is the weigh stations that pop up along the way, particularly when you transition from one state to another. Maybe it’s just getting a chance to look at something other than wheat, but weigh stations are interesting in their own right because of everything that’s going on in these massive roadside plazas. Gone are the days of a simple pull-off with a mechanical scale that was closed far more often than it was open. Today’s weigh stations are critical infrastructure installations that are bristling with sensors to provide a multi-modal insight into the state of the trucks — and drivers — plying our increasingly crowded highways.

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PLA With PETG Core Filament Put To The Test

June 26, 2025 by Maya Posch 27 Comments

The Stronghero 3D hybrid PLA PETG filament, with visible PETG core. (Credit: My Tech Fun, YouTube)

Sometimes you see an FDM filament pop up that makes you do a triple-take because it doesn’t seem to make a lot of sense. This is the case with a hybrid PLA/PETG filament by Stronghero 3D that features a PETG core. This filament also intrigued [Dr. Igor Gaspar] who imported a spool from the US to have a poke at it to see why you’d want to combine these two filament materials.

According to the manufacturer, the PLA outside makes up 60% of the filament, with the rest being the PETG core. The PLA is supposed to shield the PETG from moisture, while adding more strength and weather resistance to the PLA after printing. Another interesting aspect is the multi-color look that this creates, and which [Igor]’s prints totally show. Finding the right temperatures for the bed and extruder was a challenge and took multiple tries with the Bambu Lab P1P including bed adhesion troubles.

As for the actual properties of this filament, the layer adhesion test showed it to be significantly worse than plain PLA or PETG when printed at extruder temperatures from 225 °C to 245 °C. When the shear stress is put on the material instead of the layer adhesion, the results are much better, while torque resistance is better than plain PETG. This is a pattern that repeats across impact and other tests, with PETG more brittle. Thermal deformation temperature is, unsurprisingly, between both materials, making this filament mostly a curiosity unless its properties work much better for your use case than a non-hybrid filament.

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Revealing The Last Mac Easter Egg

June 26, 2025 by Jenny List 34 Comments

A favourite thing for the developers behind a complex software project is to embed an Easter egg: something unexpected that can be revealed only by those in the know. Apple certainly had their share of them in their early days, a practice brought to a close by Steve Jobs on his return to the company. One of the last Macs to contain one was the late 1990s beige G3, and while its existence has been know for years, until now nobody has decoded the means to display it on the Mac. Now [Doug Brown] has taken on the challenge.

The Easter egg is a JPEG file embedded in the ROM with portraits of the team, and it can’t be summoned with the keypress combinations used on earlier Macs. We’re taken on a whirlwind tour of ROM disassembly as he finds an unexpected string in the SCSI driver code. Eventually it’s found that formatting the RAM disk with the string as a volume name causes the JPEG to be saved into the disk, and any Mac user can come face to face with the dev team. It’s a joy reserved now for only a few collectors of vintage hardware, but still over a quarter century later, it’s fascinating to learn about. Meanwhile, this isn’t the first Mac easter egg to find its way here.