r/EngineeringPorn

The satellite was successfully launched aboard an Ariane-1 rocket from French Guiana on June 19, 1981

After tons of people downloaded and printed this RC chassis, I fixed the most common failure points from community feedback, added a universal body shell mount that fits any 1/8 scale shell, and built in a head-tracking FPV camera system so you can drive it from first person view.

This is what crowdsourced development looks like.

files at curvlab.com

Boat? Train? Bridge?

Big Chute Marine Railway

Rather than building locks, they built a transporter.

(Video by Suzie Gendreau)

I put this infographic together while researching how ancient civilizations developed shared systems for building, trade, and administration.

One thing that kept coming back in the sources was the importance of standard measurements. Whether it was the standardized bricks and weights of the Indus Valley, the Egyptian royal cubit, or Mesopotamian systems of weight, these weren't just technical details they made it easier for people to build, trade, and work within larger, more organized societies.

I be interested to hear how archaeologists and historians here view that relationship. Do you think standardized measurement played a major role in the growth of complex societies, or do legal and administrative institutions deserve more of the credit? Are there any excavations, studies, or publications you think I should look into?

I also wrote a longer article exploring the archaeological evidence and historical sources behind the infographic if anyone would like to read more:

https://thehistoricalinsights.page/2026/02/the-engineering-of-trust-ancient-measurement-systems-before-written-law.html

Source: @FranLab

This is the desk-stand version of the gear clocks I make. Everything, the gears, the dials and the wooden axles are laser-cut from 4mm walnut plywood and wooden rods on a 10W laser. The parts are hand sanded and polished with bee wax.
The dial hands are colored with a chrome marker.
Drawn in Illustrator, cut through LightBurn.
The video is the whole build, from flat parts to a clock that runs. It's powered by a normal quartz movement, so keeping the friction low enough for the gears to turn was the tricky part.
Happy to talk through any of the build or the laser settings.

The gears, the Fibonacci dials and the axles are all laser-cut from 4mm walnut plywood on a 10W laser. Designed in Illustrator, cut through LightBurn.

It runs on a single quartz movement — the same kind as a normal wall clock — so the whole gear train has to turn on very little torque. Getting the friction low enough was the hardest part.

In the video I'm turning the gears by hand. Adding two photos of the flat parts before assembly.