Building A Tribute Version Of Mattel’s VertiBird Toy

March 23, 2024 by Lewin Day 8 Comments

Mattel had a ton of hit toys in the 20th century. In the early 1970s, the VertiBird was one of them, letting kids pretend to fly a helicopter in circles on their loungeroom floor. An original VertiBird can be hard to come by these days, but what if you could make your own? Well, [Gord Payne] did just that!

The design of the VertiBird is simple enough that it’s easy to replicate with a 3D printer. It features a helicopter on a rod that spins around a central base. The helicopter itself has a rotor powered by a motor, with variable speed control to vary the lift it produces. The helicopter’s flight can be controlled in a circular path around the base using throttle and pitch controls. [Gord’s] build was inspired by an earlier replica from [Luke J Barker] and borrows some parts from it, too. However, this build uses an ATTiny85 microcontroller to control the helicopter’s tilt and direction with the aid of a servo.

It’s great to see this classic toy recreated from scratch, particularly given the enormous cost of original sets these days. It’s also great fun to watch [Gord] execute an aerial rescue with the toy, too. Video after the break.

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YouTuber Builds Onewheel With Tracks Instead And It’s Not Great

March 22, 2024 by Lewin Day 15 Comments

The one-wheel is a triumph of modern sensor and control technology. That made it possible to sense the acceleration and position of a platform with a single wheel, and to control that single wheel to keep the platform stable and level, even in motion. [RCLifeOn] has now taken that same concept and made it more hilarious by swapping out the wheel for a track.

The original idea was to build an electric snowboard, which worked just okay. Then, it morphed into a tank-based one-wheel instead. It’s a bit silly on the face of it, because a track is more stable than a wheel. That’s because instead of balancing on a small flattened spot of a tire, it’s got a wider, flatter footprint. But that means there’s no real need for balancing control as the track is statically stable.

The 3D-printed track assembly is driven by a powerful brushless motor via a gear drive for additional torque. Riding it is difficult on 48-volt power as it easily throws [RCLifeOn] off the board with its raw torque. At 24 volts, however, it was just barely ridable with some practice. But it was ultimately pretty terrible. It was either not moving at all, or jerking so hard that it was impossible to stay on the thing.

We’d like to see this concept tried again, perhaps with a rubber track and a more refined controller. Video after the break.

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A Binary Version Of The Enigma Machine

March 21, 2024 by Lewin Day 11 Comments

The Enigma machine is the most well-known encryption tool used by German forces in World War II, mostly because it was so famously cracked by the Allies to great effect. Like many hackers, [christofer.jh] was intrigued by the design of the Enigma, and felt compelled to build a binary version of his own design.

The original Enigma machine was designed to scramble the 26 letters in the Latin alphabet. This design is altogether simpler. Instead of 26 letters, it will scramble 1s and 0s of binary code based on the initial settings of the scrambler rings.

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Glow Plug Turned Metal-Capable 3D Printer Hotend

March 15, 2024 by Jenny List 37 Comments

At this point, most readers will be familiar with fused deposition modeling (FDM) 3D printers, and how a plastic filament is pushed through a heater and deposited as liquid through a nozzle. Most of us also know that there are a huge variety of materials that can be FDM printed, but there’s one which perhaps evades us: you can’t load a spool of metal wire into your printer and print in metal, or at least you can’t yet. It’s something [Rotoforge] is working on, with a project to make a hot end that can melt metal. Their starting point is a ceramic diesel engine glow plug, from which they expect 1300 C (2372 F).

The video below the break deals with the process of converting the glow plug, which mostly means stripping off the metal parts which make it a glow plug, and then delicately EDM drilling a hole through its ceramic tip. The video is well worth a watch for the in-depth examination of how they evolved the means to do this.

Sadly they aren’t at the point of printing metal with this thing, but we think the current progress is impressive enough to have a good chance of working. Definitely one to watch.

Previous metal 3D printers we’ve featured have often used a MIG welder.

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Reducing Seams In FDM Prints With Scarf Joint Seams

March 11, 2024 by Maya Posch 11 Comments

One unavoidable aspect of FDM 3D printing is that each layer consists out of one or more lines that have a beginning and an end. Where these join up, a seam is formed, which can be very noticeable if the same joint exists on successive layers. Taking a hint from woodworking, a possible solution is now being worked on that involves scarf joints. This research is covered by [Michael Laws] in a recent Teaching Tech video on YouTube, where he also details his own printing attempts with a custom 3D model, and a guide by [psiberfunk/Adam L].

The idea for a scarf joint was pitched practically simultaneously by [vgdh] on the PrusaSlicer GitHub, and [Noisyfox] on the OrcaSlicer GitHub. The basic idea follows the woodworking and metalworking version of a scarf joint, with the overlap between two discrete parts across two heavily tapered ends. As with the woodworking version, the FDM scarf joint is not a silver bullet, and with the under development OrcaSlicer builds a lot of the parameters are still being tweaked to optimize the result.

If it can be made to work, it could mean that scarf joints will soon be coming to an OrcaSlicer and PrusaSlicer release near you. Theoretically it should mean faster prints than with randomized seams as fewer print head adjustments are needed, and it may provide a smoother result. Definitely an interesting development that we hope to see come to fruition.

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μRepRap: Taking RepRap Down To Micrometer-Level Manufacturing

March 10, 2024 by Maya Posch 30 Comments

When the RepRap project was started in 2005 by [Dr Adrian Bowyer], the goal was to develop low-cost 3D printers, capable of printing most of their own components. The project slipped into a bit of a lull by 2016 due to the market being increasingly flooded with affordable FDM printers from a growing assortment of manufacturers. Now it seems that the RepRap project may have found a new impetus, in the form of sub-millimeter level fabrication system called the μRepRap as announced by [Vik Olliver] on the RepRap project blog, with accompanying project page.

The basic technology is based around the OpenFlexure project’s Delta Stage, which allows for very precise positioning of an imaging element, or conceivably a fabrication tool. As a first step, [Vik] upgrade the original delta stage to a much reinforced one that can accept larger NEMA17 stepper motors. This also allows for standard 3D printer electronics to control the system much like an FDM printer, only at much smaller scales and with new types of materials. The current prototype [Vik] made has a claimed step accuracy of 3 µm, with a range of tools and deposition materials being considered, including photosensitive resins.

It should be noted here that although this is a project in its infancy, it has solid foundations due to projects like OpenFlexure. Will μRepRap kickstart micrometer-level manufacturing like FDM 3D printing before? As an R&D project it doesn’t come with guarantees, but color us excited.

Thanks to [Tequin] for the tip.

How Thermal Post-Curing Resin Prints Affects Their Strength

March 10, 2024 by Maya Posch 6 Comments

Tensile strength of resin parts. (Credit: CNC Kitchen) — Credit: CNC Kitchen

Resin 3D prints have a reputation for being brittle, but [Stefan] over at [CNC Kitchen] would like to dispel this myth with the thing which we all love: colorful bar graphs backed up by scientifically appropriate experiments. As he rightfully points out, the average resin printer user will just cure a print by putting it in the sunshine or in a curing station that rotates the part in front of some UV lights. This theoretically should cause these photosensitive resins to fully cure, but as the referenced Formlabs documentation and their Form Cure station indicate, there’s definitely a thermal element to it as well.

To test the impact of temperature during the UV curing process, the test parts were put into an oven along with the UV lamp. Following this uncured, ambient cured and parts cured at 40 to 80 ºC were exposed to both tensile strength tests as well as impact strength. The best results came from the Siraya Tech Blu resin cured at 80 ºC, with it even giving FDM-printed parts a run for their money, as the following graphs make clear. This shows the value of thermal post-curing, as it anneals the resin prints. This reduces their impact strength somewhat, but massively improves their tensile strength.

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