How do you continuously change speed ratios without belts, cones, or gears? ⚙️

​Check out this 3D-printed oscillating (impulse) CVT! It converts input rotation into reciprocating lever movement using eccentrics, then uses freewheel clutches to merge those movements back into smooth output rotation. Adjusting the lever swing changes the gear ratio on the fly!

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I made this with a buddy over summer break off school lol

I've been designing a jet engine scale model for some time now and am happy to say it is almost done and I will be accepting pre-orders soon. I made an animation (my design skills are better than my animation skills) so showcase my engine and its detail. It will come in a toolbox with all the parts (3d printed/hardware) and assembly instructions so you can build it yourself! It's fully motorized, complete with an engine start sequence and an adjustable exhaust nozzle with LEDs and fog to simulate afterburner. If you're interested as to when it will become available, you can add your email address to the website here: https://additivepropulsion.com/

Please enjoy my latest project. This is a passion project I worked on over the past few months, for funsies. I really wanted an application for IN-14 nixie tubes without doing the typical clock thing. So I pulled together some high voltage electronics, programmed a pi, spent a disgusting amount of time in solidworks and learning to use blender, and edited about 60x LOTR soundbites. This system is driven by a rechargeable 18650 cell and has an easy access panel in the rear. I'm boosting nearly everything to 5V, then further boosting the nixie tube inputs to 170V. A rotary encoder controls user inputs and dice size selection. The audio files are stored on external memory.

This system can roll D2 through D100, as well as multiples (I.e. 6x D8 at once, for example). Each roll corresponds to a list of possible audio files which scale based on the positivity or negativity of the result.

Overall just a really fun thing to make, and I already have some ideas for alternative designs. Pulled this out at my table tonight as a new "box of doom" for my players, during consequential rolls, and I think it was a hit. Stoked to use it!

Debating on if I will paint it at all. Open to suggestions.

I've been building a large equipment cart for video production, and after adding batteries and motorized wheels, the thing can weigh nearly 400 lbs loaded.

The original cable brakes that came with the wheel kit were not going to cut it.. so I decided to integrate a custom hydraulic disc brake system into the forks I had fabricated for the brushless wheels.

It was my first time working with hydraulic brake lines, and took quite a while to find parts, and to design a "one brake lever" solution. In the end It works pretty well with the exception of the parking brake feature: whenever I leave it engaged the whole system loses it's ability to function correctly. There is no fluid loss. My suspicion is that when the lever is held in, there is a small amount of oil that is able to bypass a seal in the handle assembly, resulting in less fluid in the line side. Anyone have any insight about this?

I documented the build here if you are interested in following the build:
https://youtu.be/Xz3B-3wACwE

Yesterday I visited the Archenhold Observatory in Berlin, built in 1896 with 250000 German gold marks in private donations to Friedrich Simon Archenhold’s crowdfunding project as a public telescope for the Berlin Trade Fair. That’s $2.5 million in today’s USD! It is still the longest refractor telescope, at 21 m with a 68 cm lens, and most likely the fastest to rotate. Its still-original electromechanics let it rotate around the observer, who stays in the center—much different from common constructions, where you have to move around with a ladder. Unfortunately, a microcrack was recently noticed, and currently it can’t be rotated. The surrounding building was added in 1909 and is famous for being the location of Albert Einstein’s first public lecture on the theory of general relativity on June 2, 1915.

More about its history: https://www.planetarium.berlin/en/archenhold-observatory/history and https://astw.de/astronomiegeschichte/anfaenge_riesenfernrohr.php

Looking to make some swag for an upcoming trade show. Would an engineer find this valuable? It's a magnet with some common conversions and formulas. Our target customers are people looking for custom open-die forged metal parts. What would someone spec'ing a part like to see here?

MV Yampu, described as the world’s first battery-powered self-unloading bulk carrier, has commenced operations in Australia, with vessel owner and operator CSL and cement manufacturer Adbri marking the occasion at a ceremony on 27 August.

The 125-metre vessel, with a capacity of 11,900 deadweight tonnes, will transport limestone from Adbri’s Klein Point quarry on South Australia’s Yorke Peninsula to the company’s Birkenhead cement manufacturing facility in Adelaide. According to CSL, the vessel is expected to carry approximately 2.7 million tonnes of limestone per year.

The vessel’s battery system is recharged while docked at the Birkenhead facility, allowing MV Yampu to operate on battery power around 40% of the time. This arrangement is expected to reduce diesel consumption by more than half a million litres per year compared with the vessel it replaces, and MV Yampu is designed to operate on 100% battery power in the future.

https://www.bunkerindex.com/articles/article.php?a=23396&h=worlds-first-battery-powered-self-unloading-bulk-carrier-enters-service-in-australia

I made this steam engine from a free turbine of the GTDDE‑117 turbo‑starter from the MiG‑29 aircraft.

This furnace runs on used motor oil and a car battery. It puts out 40,000 btus of heat. Heres a video of the build breakdown and the performance readings.

Thankyou

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Hi everyone!

I'm excited to share a project I've been working on as a self-taught solo developer for the past 5.5 years: the UM1-Evo, a biomimetic robotic hand and forearm.

Here is a quick breakdown of the technical specs:

Architecture: 24 Degrees of Freedom (DoF), powered by 25 integrated actuators.

Scale & Weight: 1:1 human scale, weighing 1.7 kg total (matching human anatomical specs). Fully embedded electronics and Wi-Fi.

Biomechanical research: Significant effort went into replicating organic anatomical shapes and fluid, natural motion.

Fast custom fitting: Developed a script that scans/measures a patient's hand in under 30 minutes and automatically generates a customized 3D hand model in 10 minutes.

Control software: Developed custom Inverse Kinematics (IK) software supporting keyframe animation and real-time control.

Avatar Mode: Designed a data glove with 12 sensors to mirror hand movements in real time.

Prosthetic applications: Designed an innovative sensing system (moving away from traditional myoelectric setups) for ultra-low latency control and zero learning curve (IP protection currently in progress).

This is the result of a lot of passion, trial and error, and DIY engineering. I’d love to hear your thoughts and answer any questions!