Hackaday Prize 2023: The Realities Of The Homework Machine

May 8, 2023 by Matthew Carlson 83 Comments

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

May 6, 2023 by Dan Maloney 8 Comments

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

May 1, 2023 by Tom Nardi 19 Comments

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

May 1, 2023 by Bryan Cockfield 5 Comments

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

April 30, 2023 by Donald Papp 9 Comments

[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

April 29, 2023 by Lewin Day 35 Comments

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” →

Cheap Deburring Tool Is Game Changer For 3D Printing

April 27, 2023 by Lewin Day 54 Comments

3D printing’s real value is that you can whip up objects in all kinds of whacky geometries with a minimum of fuss. However, there’s almost always some post-processing to do. Like many manufactured plastic objects, there are burrs, strings, and rough edges to deal with. Fussing around with a knife to remove them is a poor way to go. As explained by [Adrian Kingsley-Hughes] on ZDNet, a deburring tool is the cheap and easy solution to the problem.

If you haven’t used one before, a deburring tool simply consists of a curved metal blade that swivels relative to its straight handle. You can drag the curved blade over the edge of a metal, wooden, or plastic object, and it neatly pulls away the burrs. There’s minimal risk of injury, unlike when pulling a regular blade towards yourself. The curved, swiveling blade is much less liable to slip or jump, and if it does, it’s far less likely to cut you.

For plastic use, just about any old deburring tool will do. They last a long time with minimal maintenance. They will wear out faster when used on metals, but you can get replacement blades cheap if you happen to need them. It’s a tool every workshop should have, particularly given they generally cost less than $20.

Given the ugly edges and rafts we’re always having to remove from our 3D prints, it’s almost egregious that printers don’t come with them bundled in the box. They’re just a bit obscure when it comes to tools; this may in fact be the first time Hackaday’s ever covered one. If you’ve got your own quality-of-life hacks for 3D printing, sound off below, or share them on the tipsline! We have able staff waiting for your email.