Inside A Dutch Street Organ: The Art Of Mechanical Music-Making

February 18, 2026 by Donald Papp 17 Comments

[James]’ Mechanical Organ of Dutch origin has been around longer than he has, but thanks to being rebuilt over the years and lovingly cared for, it delivers its unique performances just as well as it did back in the day. Even better, we’re treated to a good look at how it works.

The organ produces music by playing notes on embedded instruments, which are themselves operated by air pressure, with note arrangements read off what amounts to a very long punch card. [James] gives a great tour of this fantastic machine, so check it out in the video embedded below along with a couple of its performances.

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3D Printing Pneumatic Channels With Dual Materials For Soft Robots

February 13, 2026 by Maya Posch 3 Comments

Pneumatics are a common way to add some motion to soft robotic actuators, but adding it to a robot can be somewhat of a chore. A method demonstrated by [Jackson K. Wilt] et al. (press release, preprint) involves using a 3D printing to extrude two materials: one elastomeric material and a fugitive ink that is used to create pneumatic channels which are dissolved after printing, leaving the empty channels to be filled with air.

By printing these materials with a rational, multi-material (RM-3DP) custom nozzle it’s possible to create various channel patterns, controlling the effect of compressed air on the elastomeric material. This way structures like hinges and muscles can be created, which can then be combined into more complex designs. One demonstrated design involves a human-like hand with digits that can move and grasp, for example.

In the demonstration the elastomeric material is photopolymerizable polyurethane-acrylate resin, with the fugitive ink being 30 wt% Pluronic F-127 in water. The desired pattern is determined beforehand with a simulation, followed by the printing and UV curing of the elastomeric resin.

As is typical of soft robotics implementations, the resulting robots are more about a soft touch than a lot of force, but could make for interesting artificial muscle designs due to how customizable the printing process is.

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Tech In Plain Sight: Pneumatic Tubes

November 17, 2025 by Al Williams 44 Comments

Today, if you can find a pneumatic tube system at all, it is likely at a bank drive-through. A conversation in the Hackaday bunker revealed something a bit surprising. Apparently, in some parts of the United States, these have totally disappeared. In other areas, they are not as prevalent as they once were, but are still hanging in there. If you haven’t seen one, the idea is simple: you put things like money or documents into a capsule, put the capsule in a tube, and push a button. Compressed air shoots the capsule to the other end of the tube, where someone can reverse the process to send you something back.

These used to be a common sight in large offices and department stores that needed to send original documents around, and you still see them in some other odd places, like hospitals or pharmacy drive-throughs, where they may move drugs or lab samples, as well as documents. In Munich, for example, a hospital has a system with 200 stations and 1,300 capsules, also known as carriers. Another medical center in Rotterdam moves 400 carriers an hour through a 16-kilometer network of tubes. However, most systems are much smaller, but they still work on the same principle.

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A set of three linear actuators set atop a green with yellow grid cutting mat. The electric actuator on the top of the image is silver and has a squarish tube. It is slender compared to the other two. A black, hydraulic actuator sits in the middle and is the largest of the three. A silver pneumatic actuator at the bottom of the image is the middle sized unit.

Linear Actuators 101

August 28, 2025 by Navarre Bartz 16 Comments

Linear actuators are a great help when you’re moving something along a single axis, but with so many options, how do you decide? [Jeremy Fielding] walks us through some of the high level tradeoffs of using one type of actuator over another.

There are three main types of linear actuator available to the maker: hydraulic, pneumatic, and electric. Both the hydraulic and pneumatic types move a cylinder with an attached rod through a tube using pressure applied to either side of the cylinder. [Fielding] explains how the pushing force will be greater than the pulling force on these actuators since the rod reduces the available surface area on the cylinder when pulling the rod back into the actuator.

Electric actuators typically use an electric motor to drive a screw that moves the rod in and out. Unsurprisingly, the electric actuator is quieter and more precise than its fluid-driven counterparts. Pneumatic wins out when you want something fast and without a mess if a leak happens. Hydraulics can be driven to higher pressures and are typically best when power is the primary concern which is why we see them in construction equipment.

You can DIY your own linear actuators, we’ve seen tubular stepper motors, and even a linear actuator inspired by muscles.

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Standing Desk Uses Pneumatics To Do The Job

June 27, 2025 by Lewin Day 7 Comments

Most standing desks on the market use electric motors or hand cranks to raise and lower the deck. However, [Matthias Wandel] found a Kloud standing desk that used an altogether different set up. He set about figuring out how it worked in the old-fashioned way—by pulling it apart.

The Kloud desk relies on pneumatics rather than electrical actuators to move up and down. Inside the desk sits a small tank that can be pressurized with a hand-cranked mechanism. A lever can then be used to release pressure from this tank into a pair of pneumatic cylinders that drive the top of the desk upwards. The two cylinders are kept moving in sync by a tensioned metal ribbon that ties the two sides together. The mechanism is not unlike a gas lift chair—holding the lever and pushing down lets the desk move back down. Once he’s explained the basic mechanism, [Matthias] gets into the good stuff—pulling apart the leg actuator mechanism to show us what’s going on inside in greater detail.

If you’ve ever thought about building your own standing desk, this might be a video worth watching. We’ve featured some other great pneumatics projects before, too. Video after the break.

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Robot Gets A DIY Pneumatic Gripper Upgrade

April 25, 2025 by Lewin Day 2 Comments

[Tazer] built a small desktop-sized robotic arm, and it was more or less functional. However, he wanted to improve its ability to pick things up, and attaching a pneumatic gripper seemed like the perfect way to achieve that. Thus began the build!

The concept of [Tazer]’s pneumatic gripper is simple enough. When the pliable silicone gripper is filled with air, the back half is free to expand, while the inner section is limited in its expansion thanks to fabric included in the structure. This causes the gripper to deform in such a way that it folds around as it fills with air, which lets it pick up objects. [Tazer] designed the gripper so that that could be cast in silicone using 3D printed molds. It’s paired with a 3D printed manifold which delivers air to open and close the gripper as needed. Mounted on the end of [Tazer]’s robotic arm, it’s capable of lifting small objects quite well.

It’s a fun build, particularly for the lovely sounds of silicone parts being ripped out of their 3D printed molds. Proper ASMR grade stuff, here. We’ve also seen some other great work on pneumatic robot grippers over the years.

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DIY Air Bearings, No Machining Required

October 20, 2024 by Dan Maloney 26 Comments

Seeing a heavy load slide around on nearly frictionless air bearings is pretty cool; it’s a little like how the puck levitates on an air hockey table. Commercial air bearings are available, of course, but when you can build these open-source air bearings, why bother buying?

One of the nice things about [Diffraction Limited]’s design is that these bearings can be built using only simple tools. No machining is needed past what can be easily accomplished with a hand drill, thanks to some clever 3D-printed jigs that allow you to drill holes with precision into stainless steel discs you can buy on the cheap. An extremely flat surface is added to the underside of these discs thanks to another jig, some JB Weld epoxy, and a sheet of float glass to serve as an ultra-flat reference. Yet more jigs make it easy to scribe air channels into the flat surface and connect them to the air holes through a bit of plaster of Paris, which acts as a flow restriction. The video below shows the whole process and a demo of the bearings in action.

[Diffraction Limited] mentions a few applications for these air bearings, but the one that interests us most is their potential use in linear bearings; a big CNC cutter using these air bearings would be pretty cool. We seen similar budget-friendly DIY air bearings before, including a set made from used graphite EDM electrodes.

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