It is no secret that we like slide rules around the Hackaday bunker, and among our favorites are the cylindrical slide rules. [Chris Staecker] likes them, too, and recently even 3D printed a version. But spurred by comments on his video, he decided to try something that might be unique: a helical slide rule. You can see how it works in the video below.
With a conventional slide rule, the scale is rotated around a cylinder so that it is the same length as a much longer linear scale. However, this new slide rule bends the entire rule around a cylinder and allows the slide to move, just like a conventional slide rule. If you have a 3D printer, you can make your own.
Adding textures is a great way to experiment with giving 3D prints a different look, and [PandaN] shows off a method of adding a wood grain effect in a way that’s easy to play around with. It involves using a 3D model of a log (complete with concentric tree rings) as a print modifier. The good news is that [PandaN] has already done the work of creating one, as well as showing how to use it.
The model of the stump — complete with concentric tree rings — acts as a modifier for the much-smaller printed object (in this case, a small plate).
In the slicer software one simply uses the log as a modifier for an object to be printed. When a 3D model is used as a modifier in this way, it means different print settings get applied everywhere the object to be printed and the modifier intersect one another.
In the case of this project, the modifier shifts the angle of the fill pattern wherever the models intersect. A fuzzy skin modifier is used as well, and the result is enough to give a wood grain appearance to the printed object. When printed with a wood filament (which is PLA mixed with wood particles), the result looks especially good.
In addition to the 3D models, [PandaN] provides a ready-to-go project for Bambu slicer with all the necessary settings already configured, so experimenting can be as simple as swapping the object to be printed with a new 3D model. Want to see that in action? Here’s a separate video demonstrating exactly that step-by-step, embedded below.
You can buy all sorts of RC cars off the shelf, but doing so won’t teach you a whole lot. Alternatively, you could follow [TRDB]’s example, and design your own from scratch.
The Lizard, as it is known, is a fun little RC car. It’s got a vaguely Formula 1-inspired aesthetic, and looks fetching with the aid of two-tone 3D printed parts. It’s designed for speed and handling, with a rear-wheel-drive layout and sprung suspension at all four corners to soak up the bumps. The majority of the vehicle is 3D printed in PETG, including the body and the gearbox and differential. However, some suspension components are made in TPU for greater flexibility and resistance to impact. [TRDB] specified commercial off-the-shelf wheels to provide good grip that couldn’t easily be achieved with 3D-printed tires. An ESP32 is responsible for receiving commands from [TRDB’s] custom RC controller running the same microcontroller. It sends commands to the speed controller that runs the Lizard’s brushed DC motor from a 3S lithium-polymer battery.
The final product looks sleek and handles well. It also achieved a GPS-verified top speed of 48 km/h as per [TRDB’s] testing. We’ve seen some other great DIY RC cars over the years, too, like this example that focuses on performance fundamentals. Video after the break.
Sometimes, you find yourself in need of a coil. You could sit around winding thousands of turns of copper wire yourself, but that would be remarkably tedious. Thus, instead, you might follow the example of [OJengineering] and choose to get a machine to do it for you.
This build first popped up on on Reddit, with [OJengineering] explaining that they had repurposed an Ender 3 Pro 3D printer to wind a stator for them. The reasoning was sound—a replacement stator for their motorcycle cost $1000 in their local area, so rewinding their own would be much cheaper. The idea was straightforward enough—the 3D printer was a capable motion control platform that really just needed to be retooled to drag wire around instead of squirting hot plastic. In a later update, they explained that they had created a Python program that spits out appropriate stator winding G-code from user-entered parameters. This G-code commands the 3D printer’s head to make rectangle winds around the stator core while moving up and down to appropriately distribute the wire. The device can be seen in action in a video on YouTube.
It’s a hacky build, but one that does nevertheless get the winding done. That’s the thing about 3D printers—they’re really just simple motion systems that can do whatever you tell them. You just need a way to generate the right G-code to do the job.
The OrcaSlicer staggered perimeters in an FDM print, after slicing through the model. (Credit: CNC Kitchen)
The idea of staggered (or brick) layers in FDM prints has become very popular the past few years, with now nightly builds of OrcaSlicer featuring the ‘Stagger Perimeters’ option to automate the process, as demonstrated by [Stefan] in a recent CNC Kitchen video. See the relevant OrcaSlicer GitHub thread for the exact details, and to obtain a build with this feature. After installing, slice the model as normal, after enabling this new parameter in the ‘Strength’ tab.
In the video, [Stefan] first tries out a regular and staggered perimeter print without further adjustments. This perhaps surprisingly results in the staggered version breaking before the regular print, which [Stefan] deduces to be the result of increasing voids within the print. After increasing the extrusion rate to 110% to fill up said voids, this does indeed result in the staggered part showing a massive boost in strength.
What’s perhaps more telling is that a similar positive effect is observed when the flow is increased with the non-staggered part, albeit with the staggered part still showing more of a strength increase. This makes it obvious that just staggering layers isn’t enough, but that the flowrate and possibly other parameters have to be adjusted as well to fully realize the potential of brick layers. That said, it’s encouraging to see this moving forward despite questionable patent claims.
A treadmill-style bed can be a great addition to a 3D printer. It allows prints to be shifted out of the build volume as printing continues, greatly increasing the size and flexibility of what you can print. But [Ivan Miranda] and [Jón Schone] had a question. Instead of making a treadmill to suit a 3D printer, what if you just built a 3D printer on top of a full-size treadmill?
The duo sourced a piece of real gym equipment for this build. They then set about building a large-scale 3D printer on top of this platform. The linear rails were first mounted on to the treadmill’s frame, followed by a gantry for the print head itself and mounts for the necessary stepper motors. The printer also gained a custom extra-large extruder to ensure a satisfactory print speed that was suitable for the scale of the machine. From there, it was largely a case of fitting modules and running cables to complete the printer.
Soon enough, the machine was printing hot plastic on the treadmill surface, thereby greatly expanding the usable print volume. It’s a little tricky to wrap your head around at first, but when you see it in action, it’s easy to see the utility of a build like this, particularly at large scale. [Ivan] demonstrated this by printing a massive girder over two meters long.
The AI effects we know these days were once preceded by CGI, and those were once preceded by true hand-built physical props. If that makes you think of Muppets, this video will change your mind. In a behind-the-scenes look with [Adam Savage], effects designer [Mark Setrakian] reveals the full animatronic glory of Mr. Wink’s mechanical fist from Hellboy II: The Golden Army (2008) – and this beast still flexes.
Most of this arm was actually made in 2003, when 3D printing was very different than what we think of today. Printed on a Stratasys Titan – think: large refrigerator-sized machine, expensive as sin – the parts were then hand-textured with a Dremel for that war-scarred, brutalist feel. This wasn’t just basic animatronics for set dressing. This was a fully actuated prop with servo-driven finger joints, a retractable chain weapon, and bevel-geared mechanisms that scream mechanical craftsmanship.
Each finger is individually designed. The chain reel: powered by a DeWalt drill motor and custom bevel gear assembly. Every department: sculptors, CAD modelers, machinists, contributed to this hybrid of analog and digital magic. Props like this are becoming unicorns.
