FreeCAD 1.1 Tutorial, For Beginners Who Like Clear Instructions

May 13, 2026 by Donald Papp 59 Comments

If you’ve been interested in FreeCAD but haven’t known where to start, here’s a wonderful video tutorial for FreeCAD 1.1 by [Deltahedra] aimed squarely at how to model a 3D part from scratch while also following best engineering practices for part design. It focuses on a concise and meaningful workflow that respects your time and doesn’t make assumptions about skill level. It even starts by taking a few moments to explain how to navigate the interface, a courtesy many will appreciate.

FreeCAD can do quite a lot, so a tutorial that focuses on a specific yet broadly-applicable task with a clear context is a great way to narrow the scope into something manageable, and be comprehensive without getting bogged down in minutiae. [Deltahedra] does this by exclusively using the part design workbench, demonstrating what to do to make a part step-by-step, and showing common mistakes that can happen and how to fix them if they occur. Beyond that, it’s left up to the curious hacker to delve for themselves into what else FreeCAD has to offer.

Since 1.1 is (at this writing) the latest stable release, one can also be confident that the tutorial will match the user interface and features one sees on their own screen. After all, it can be frustrating to attempt to follow a tutorial only to find out things are a few versions behind and nothing is where one expects it to be.

Best practices aren’t just fussy rules about how to do things, and [Deltahedra] demonstrates this by showing how certain procedures just plain make more sense when designing shapes. Our own Arya Voronova has also shared best practices for FreeCAD, so check that out for some added perspective. You’ll be wielding FreeCAD in confidence and comfort in no time.

Thanks for the tip, [Vik Olliver]!

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VTech Toy Becomes PinkPad, The DIY Linux Laptop

May 13, 2026 by Donald Papp 4 Comments

Originally envisioned as a simple DIY laptop project, [kati]’s PinkPad V1 ended up being considerably more involved than expected. But the end result is a perfectly usable, stunningly pink, and remarkably sturdy portable laptop that looks nothing like a hack job.

The PinkPad V1 started as a toy laptop for toddlers, repurposed into a DIY laptop running Linux while keeping the original clamshell design and cute aesthetic. As [kati] herself points out, while it may not seem particularly difficult to yank out a toy’s insides and stuff it with a Raspberry Pi, most of the real challenges were related to actually getting all the necessary parts and connectors and wiring to actually fit in a useful way. As anyone with experience in building something knows, working around existing enclosures or hardware almost always brings unexpected challenges.

The original toy laptop? Produced by none other than VTech, whose products have been hacked to create things like a punch card-reading cyberdeck and Z80 hacking station. Our own [Tom Nardi] has also shared his fondness for these devices in several teardowns over the years.

In the end, [kati]’s PinkPad ended up sporting a mini keyboard (whose black keys were turned pink with a little nail polish) and a 5 inch touchscreen LCD. Combined with a rechargeable power supply, it provides all the comforts of an Arch Linux ARM mini laptop.

Thanks [alex] for the tip!

This Random Number Generator Does It With Neon

May 12, 2026 by Donald Papp 16 Comments

The quest for true randomness has roots in cryptography and is a rabbit hole that gets surprisingly deep with alarmingly rapidity. Still, the generation of random-enough numbers is a popular hacker project. Part of the appeal is the way these devices strive to incorporate physical phenomena, and in [Joshua Coleman]’s case, his Neon Entropy (Pseudo) Random Number Generator uses a trio of vintage neon lamps.

Neon lamps discharge at rates that vary unpredictably. They’re also pretty to look at.

[Joshua] chose neon lamps in part because the discharge rate of an energized lamp is a variable, physical process that makes a good source of entropy. They also have an attractive visual appeal that fits the concept [Joshua] had in mind. Unlike random number generators that kick off by measuring radiation or some other imperceptible thing, it’s possible — at least in a sense — to see this one working.

The small variations in the three neon lamps are measured optically by three TEPT4400 ambient light sensors (isolated from the neon lamps themselves) and turned into analog signals. A Raspberry Pi Pico W reads these signals, then uses them in a process that culminates in SHA-256 64-bit values that can be used as random seeds.

There’s also a web dashboard that shows everything live, furthering the “watch it work” concept [Joshua] is aiming for. The video below shows the project in action if you want to see how the sausage gets made.

Earlier we mentioned how random number generators are popular projects among hackers, and here are a few selected ones. Don’t miss the stylish glow and slick enclosure of this Nixie tube RNG, or the lava lamp RNG which is in fact not a gimmick. And while it is commonly understood that meaningful randomness must come from outside a digital chip, uninitialized internal volatile RAM — if accessed correctly — can be a remarkably good source of entropy.

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Want Driving Simulator Feedback? Make The Robot Do It

May 11, 2026 by Donald Papp 29 Comments

Humanoid robots are a thing now, and here’s an interesting research project that explores using one as a form of haptic media. Specifically, using a humanoid robot to move a chair while one plays a VR driving simulator.

Here’s how it works: a Unitree G1 robot sits behind a player’s chair and grasps it with its hands. Spherical markers on the chair help the robot’s depth camera know the chair’s position, and real-time G-force signals fed from the simulator (Assetto Corsa, running on PC) tell the robot how much and in what direction to shift the chair to match in-simulator events.

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How To Avoid Failed Screw Holes In 3D Printed Parts

May 7, 2026 by Donald Papp 21 Comments

Screws are useful fasteners for 3D prints, but the effectiveness of a screw (not to mention the ease or hassle of insertion) depends on the hole itself. This comprehensive guide on how to design screw holes in 3D printed parts takes guesswork out by providing reference tables as well as useful general tips.

The guide provides handy tables saying exactly how big to design a hole depending on screw type, material (PLA, PETG, or high-flow PETG) and whether the hole is printed in a vertical or horizontal orientation. This takes the guesswork out of screw hole design.

There’s no reason to guess the right size of hole for a screw, just refer to some handy tables.

The reason for different numbers is because multiple (but predictable) variables affect a 3D-printed hole’s final dimensions. Shrinkage, filament properties, and printing orientation can all measurably affect small features like screw holes; accounting for these is the difference between a good fit, and cracking or stripping.

In addition to the tables, there are loads of other useful tips. Designing lead-ins makes screws easier to insert and engage, and while increasing walls is an easy way to add strength it’s also possible to use 3D-printed microfeatures which are more resistant to distortion and don’t depend on slicer settings. There’s even suggested torque amounts for different screw and material types.

Sure, the most reliable way to get a hole of a known size is to drill it out yourself. But that’s an extra step, and drill bits aren’t always at hand in the desired sizes. The guide shows that it is entirely possible to print an ideal screw hole by taking a few variables into account.

If your design calls for screws, be sure to check it out and see if there’s anything you can use in your own designs.

How To Better Enjoy VR On Linux

May 6, 2026 by Donald Papp 18 Comments

Linux folks are used to having to roll many of their own solutions, and better Linux desktop usability is a goal of the WayVR project, which aims to provide desktop control and app launching from within a VR session.

VR applications can already stream from Linux to standalone headsets with projects like WiVRn (check out this WiVRn setup guide for a fuller understanding), but what WayVR does is let one launch programs and access desktop screens within VR. Put another way, instead of the headset being limited to acting as a pseudo-monitor that only receives the output of an already-running VR application, the headset and controllers can now be used to interact with one’s computer as if one were physically sitting at it. Controls and user interface are highly flexible and help users to do anything they need — including clicking, typing, and launching applications. It’s a considerable step forward for convenience and general usability.

Naturally, when it comes to using a computer from within VR there is plenty of unexplored territory regarding user interfaces. It’s fertile ground for experimentation in everything from DIY headsets to ways to input text without a keyboard, so if you enjoy working on the frontiers of such things, it’s a good scene to dive into.

The Threadless Ball Screw Never Took Off, But Don’t Write It Off

April 2, 2026 by Donald Papp 37 Comments

If you’ve never heard of the threadless ball screw, which was invented over sixty years ago, [Angus] of Maker’s Muse has a video demonstrating the whole thing, covering its history and showcasing both its strengths and weaknesses. If you like seeing mechanical assemblies in action, give it a watch.

The device — consisting of little more than a smooth rod and three angled ball bearings — is a way to turn rotational motion into linear motion. Not a single belt, thread, or complex mechanical assembly in sight. While a simple nut on a threaded rod can turn rotation into linear motion, those come with their own issues. The threadless ball screw was one effort at finding a better way.

While it lacks precision, the threadless ball screw nevertheless offers quiet and smooth motion with adjustable tension in a very DIY-friendly design.

Threadless ball screws never really took off, although they were given some consideration for use in 3D printers back in the RepRap days. Today one can purchase quality CNC components without leaving one’s web browser, but back in the early 2000s things like lead screws and ball screws were rather more specialized, less accessible, and more expensive than they are today. RepRap folks had to make their own solutions. But while the threadless ball screw is a very DIY-friendly design, it was ultimately lacking in performance.

The main problem is they’re just not precise enough for anything like CNC work. [Angus] does some back-and-forth tests with a 3D printed unit that shows serious drift after only a few minutes. Now, he knows perfectly well that his 3D-printed test unit is far from ideal, but the rapidity at which it drifted was still a surprise. Making a carriage with two threadless ball screws — one at each end — performed a lot better, but was ultimately still flawed.

It’s not all bad. There’s zero backlash. They are mechanically simple, remarkably smooth, and utterly quiet. Also, [Angus] discovered that the maximum force this setup can be made to apply is surprisingly significant, and is directly related to the tension on the bearings. That means one can trivially adjust how easily the carriage slips (or doesn’t) just by tightening or loosening the screw holding each bearing.

Sure, they’re not precise. But maybe you don’t need precision. Maybe you just need to move something back and forth in a strong & silent sort of way that can still slip gracefully (and quietly) if something goes awry, like bottoming out an axis. 3D printing makes it pretty easy to whip one up, so maybe there’s still a place for the threadless ball screw.

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