A 3D printed copper aerospike engine cutaway showing the intricate, organic-looking channels inside. It is vaguely reminiscent of a human torso and lungs.

3D Printed Aerospike Was Designed By AI

We’re still in the early days of generatively-designed objects, but when combined with the capabilities of 3D printing, we’re already seeing some interesting results. One example is this new copper aerospike engine. [via Fabbaloo]

A collaboration between startups Hyperganic (generative AI CAD) and AMCM (additive manufacturing), this 800 mm long aerospike engine may be the most complicated 3D print yet. It continues the exciting work being done with 3D printing for aerospace applications. The complicated geometries of rocket nozzles of any type let additive manufacturing really shine, so the combination of generative algorithms and 3D printed nozzles could result in some big leaps in coming years.

Aerospikes are interesting as their geometry isn’t pressure dependent like more typical bell-shaped rocket nozzles meaning you only need one engine for your entire flight profile instead of the traditional switching mid-flight. A linear aerospike engine was one of the main selling points for the cancelled VentureStar Space Shuttle replacement.

This isn’t the only generative design headed to space, and we’ve covered a few projects if you’re interested in building your own 3D printed rocket nozzles or aerospike engines. Just make sure you get clearance from your local aviation regulator before your project goes to space!

Hackaday Prize 2023: The Realities Of The Homework Machine

For those outside the world of education, it can be hard to judge the impact that ChatGPT has had on homework assignments. If you didn’t know, the first challenge of the 2023 Hackaday Prize is focused on improving education. [Devadath P R] decided that the best way to help teachers and teaching culture was to confront them head-on with our new reality by building the homework machine.

The goal of the machine is to be able to stick in any worksheet or assignment and have it write out the answers in your own handwriting, and so far, the results are pretty impressive. There are already pen holder tools for 3D printers, but they often have a few drawbacks. Existing tools often take quite a while to generate G-Code for long pages of text. Hobby servos to lift the pen up and down take more wear than you’d expect as a single page has thousands of actuations. Vibrations are also a problem as they are a dead giveaway that the text was not human-written. [Devadath] created a small Python GUI to record their particular handwriting style on a graphics tablet and used ChatGPT to generate answers. Continue reading “Hackaday Prize 2023: The Realities Of The Homework Machine”

Laser Triangulation Makes 3D Printer Pressure Advance Tuning Easier

On its face, 3D printing is pretty simple — it’s basically just something to melt plastic while being accurately positioned in three dimensions. But the devil is in the details, and there seems to be an endless number of parameters and considerations that stand between the simplicity of the concept and the reality of getting good-quality prints.

One such parameter that had escaped our attention is “pressure advance,” at least until we ran into [Mike Abbott]’s work on automating pressure advance calibration on the fly. His explanation boils down to this: the pressure in a 3D printer extruder takes time to both build up and release, which results in printing artifacts when the print head slows down and speeds up, such as when the print head needs to make a sharp corner. Pressure advance aims to reduce these artifacts by adjusting filament feed speed before the print head changes speed.

The correct degree of pressure advance is typically determined empirically, but [Mike]’s system, which he calls Rubedo, can do it automatically. Rubedo uses a laser line generator and an extruder-mounted camera (a little like this one) to perform laser triangulation. Rubedo scans across a test print with a bunch of lines printed using different pressure advance values, using OpenCV to look for bulges and thinning caused when the printer changed speed during printing.

The video below gives a lot of detail on Rubedo’s design, some shots of it in action, and a lot of data on how it performs. Kudos to [Mike] for the careful analysis and the great explanation of the problem, and what looks to be a quite workable solution.

Continue reading “Laser Triangulation Makes 3D Printer Pressure Advance Tuning Easier”

Cocoa Press Chocolate 3D Printer Offered As DIY Kit

Ultimately, the goal of Hackaday is to shine a light on the incredible projects coming from the hardware hacking community. In the vast majority of cases, said projects end up being one-off creations — a clever solution that solved a specific problem for the creator, which may or may not be directly applicable to anyone else. But occasionally, perhaps one in every few thousand projects, we see an idea that’s compelling enough to become a commercial product.

Today, we’re happy to add the Cocoa Press to that list. Creator [Ellie Weinstein] has recently unveiled a commercialized version of the chocolate 3D printer she’s been working on for several years, and true to the maker spirit, it’s being offered as a DIY kit. You can currently put a $100 USD deposit on the final product, which is expected to ship before the end of the year. Assembly time is estimated to be around 10 hours and no previous experience with building 3D printers is required, though we’re sure it wouldn’t hurt.

Continue reading “Cocoa Press Chocolate 3D Printer Offered As DIY Kit”

Hinges Live Inside 3D Prints

Since desktop 3D printers have become more common, we’ve seen dramatic shifts in all kinds of areas such as rapid prototyping, antique restoration, mass production of consumer goods, or even household repairs that might not have been possible otherwise. There are a lot of unique manufacturing methods that can be explored in depth with a 3D printer as well, and [Slant 3D] demonstrates how one such method known as the living hinge can be created with this revolutionary new tool.

Living hinges, unlike a metal hinge you might pick up at a hardware store, are integrated into the design of the part and made of the same material. Typically found in plastic containers, they allow for flexibility while keeping parts count and cost low. The major downside is that they create stresses in the materials when used, so their lifespan is finite. But there are a number of ways to extend their life, albeit with a few trade-offs.

The first note is to make sure that you’re using the right kind of plastic, but after that’s taken care of [Slant 3D] builds a few flexible parts starting with longer circular-shaped living hinge which allows greater range of motion and distributes the forces across a wider area, at a cost of greater used space and increased complexity. A few other types of living hinges are shown to use less space in some areas, but make the hinges only suitable for use in other narrower applications.

One of the more interesting living hinges he demonstrates is one that’s more commonly seen in woodworking, known there as a kerf bend. By removing strips of material from a sheet, the entire sheet can be rotated around the cuts. In woodworking this is often done by subtracting material with a CNC machine or a laser cutter, but in 3D printing the voids can simply be designed into the part.

Continue reading “Hinges Live Inside 3D Prints”

Embed Hardware Into 3D Prints, But Not In The Way You’re Thinking

[Christopher Helmke] is doing fantastic work in DIY systems for handling small hardware like fasteners, and that includes robotic placement of hardware into 3D prints. Usually this means dropping nuts into parts in mid-print so that the hardware is captive, but that’s not really the story here.

The really inventive part we want to highlight is the concept of reducing packaging and labor. Instead of including a zip-lock bag of a few bolts, how about embedding the bolts into a void in the 3D print, covered with a little snip-out retainer? Skip ahead to 1:54 in the video to see exactly what we mean. It’s a pretty compelling concept that we hope sparks a few ideas in others.

As clever as that concept is, the rest of the video is also worth a watch because [Christopher] shows off a DIY system that sits on top of his 3D printer and takes care of robotically placing the hardware in mid-print. He talks all about the challenges of such a system. It’s not perfect (yet), but seeing it in action is very cool.

We’ve recently seen a lot of fascinating stuff when it comes to [Christopher Helmke]’s automated handling of fasteners and similar hardware. His system makes rapid and accurate dispensing of bolts look easy, and his work on using compressed air to zip pieces around seems effective.

Continue reading “Embed Hardware Into 3D Prints, But Not In The Way You’re Thinking”

Alternatives To Pins And Holes For 3D Printed Assemblies

When we have two 3D printed parts that need to fit together, many of us rely on pins and holes to locate them and fix them together. [Slant 3D] has explored some alternative ideas in this area that may open up new avenues for your own designs.

Their first idea was to simply chamfer the pins and holes. This allows the object to be printed in a different orientations without compromising the fit. It also makes the features less brittle and creates a broader surface for gluing. Another alternative is using fins and slots, which again add robustness compared to flimsy pins. By chamfering the edges of the fins, they can be printed vertically for good strength and easy location without the need for support material.

Neither option requires much extra fuss compared to typical pin-and-hole designs. Plus, both are far less likely to snap off and ruin your day. Be honest, we’ve all been there. Meanwhile, consider adding folded techniques to your repertoire, too.

Continue reading “Alternatives To Pins And Holes For 3D Printed Assemblies”