3d Printer hacks

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DIY High Flow 3D Printing

December 25, 2021 by 5 Comments

Sometimes we’re impressed by the sheer audacity of a project. [Stefan] rarely disappoints in that area, and his latest video shows him making an adapter to convert a normal 3D printed nozzle into a high-flow nozzle, similar to one you’d find on a Volcano. We say similar because [Stefan] took the trouble to drill three holes in the adapter to increase the melting surface area. The audacious part is that he doesn’t really have the machine shop to drill three tiny precision holes in close proximity — and he shows us the pictures to prove that he didn’t get it right the first (or fifth) time. But he did stick with it and got good results.

Why do such a thing? He wanted to mount the high-efficiency nozzles he’s been experimenting with on the Volcano extruder. The commercial one, in particular, doesn’t come in the extended size. To simplify things, he started with a long brass insert. The conical hex cut offers a natural center point if you are satisfied with a single hole through the center of the adapter. The hex cutout allows you to use a key to install or remove the spacer easily.

The idea behind the longer nozzles is that the filament has more time at temperature and can therefore move faster and still melt. The additional surface area should help, too. Of course, [Stefan] does plenty of testing and you can see the results in the video. A Volcano nozzle started misbehaving around 25 mm/s but at 30 mm/s, things started going bad. The CHT nozzle on the homemade standard spacer stayed working up to 30 mm/s and even at 60 mm/s was doing better than the standard nozzle at 45 mm/s. Sadly, the multiple holes in the special adapter caused worse extrusion performance, presumably by increasing pressure in the extrusion system. However, it did work well in real-life printing. Since the single bore adapter and the CHT nozzle worked great we don’t think it would be worth making the more complex one, as impressive a feat as that was.

[Stefan] thinks a lot about nozzles. He worries about wear, of course. He also built his own version of the high-flow nozzle.

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3D Printing Gets Tiny

December 25, 2021 by 6 Comments

Using a process akin to electroplating, researchers at the University of Oldenburg have 3D printed structures at the 25 nanometer scale. A human hair, of course, is thousands of time thicker than that. The working medium was a copper salt and a very tiny nozzle. How tiny? As small as 1.6 nanometers. That’s big enough for two copper ions at once.

Tiny nozzles are prone to every 3D printer’s bane: clogged nozzles. To mitigate this, the team built a closed-loop control that measured electrical current between the work area and inside the nozzle. You can read the full paper online.

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3D Prints With A Mirror Finish

December 25, 2021 by 15 Comments

As anyone who has used a 3D printer before knows, what comes off the bed of your regular FSD printer is by no means a mirror finish. There are layers in the print simply by the nature of the technology itself, and the transitions between layers will never be smooth. In addition, printers can use different technology for depositing layers, making for thinner layers (SLA, for example). With those challenges in mind, [AlphaPhoenix] set out to create an authentic mirror finish on his 3D prints. (Video, embedded below.)

As the intro hints, mirrors need very flat/smooth surfaces to reflect light. To smooth his prints, [AlphaPhoenix] first did a light sanding pass and then applied very thick two-part epoxy, allowing surface tension to do the smoothing work for him. Once dried, silver was deposited onto the pieces via a few different sprays. First, a wetting agent is applied, which prevents subsequent solutions from beading up. Next, he sprays the two precursors, and they react together to deposit elemental silver onto the object’s surface. [AlphaPhoenix] asserts that he isn’t a chemist and then explains some of the many chemical reactions behind the process and theorizes why the solutions break down a while after being mixed.

He had an excellent first batch, and then subsequent batches came out splotchy and decided un-mirror-like. As we mentioned earlier, the first step was a wetting agent, which tended to react with the epoxy that He applied. Then, using a grid search with four variables, [AlphaPhoenix] trudged through the different configurations, landing on critical takeaways. For example, the curing time for the epoxy was essential and the ratio between the two precursor solutions.

Recently we covered a 3D printed mirror array that concealed a hidden message. Perhaps a future version of that could have the mirror integrated into the print itself using the techniques from [AlphaPhoenix]?

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Do You Need A Cycloidal Drive?

December 25, 2021 by 10 Comments

A cycloidal gear drive is one of the most mesmerizing reduction gears to watch when it is running, but it’s not all just eye-candy. Cycloidals give decent gearing, are relatively compact and back-drivable, and have low backlash and high efficiency. You probably want one in the shoulder of your robot arm, for instance.

But designing and building one isn’t exactly straightforward. Thanks, then, to [How To Mechatronics] for the lovely explanation of how it works in detail, and a nice walkthrough of designing and building a cycloidal gear reducer out of 3D printed parts and a ton of bearings. If you just want to watch it go, check out the video embedded below.

The video is partly an ad for SolidWorks, and spends a lot of time on the mechanics of designing the parts for 3D printing using that software. Still, if you’re using any other graphical CAD tool, you should be able to translate what you learned.

It’s amazing that 3D printing has made sophisticated gearbox designs like this possible to fabricate at home. This stuff used to be confined to the high-end machine shops of fancy robotics firms, and now you can make one yourself this weekend. Not exotic or unreliable enough for you? Well, then, buy yourself some flexible filament and step on up to the strain wave, aka “harmonic drive”, gearbox.

Thanks to serial tipster [Keith] for the tip!

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Belt-drive 3D-printer extruder

Back-to-Back Belts Drive Filament In This Unique Extruder Design

December 23, 2021 by 18 Comments

It’s hard to say when inspiration will strike, or what form it’ll take. But we do know that when you get that itch, it’s a good idea to scratch it, because you might just end up with something like this cool new design for a 3D printer extruder as a result.

Clearly, the world is not screaming out for new extruder designs. In fact, the traditional spring-loaded, toothed drive wheel on a stepper really does the job of feeding filament into a printer’s hot end just fine, all things considered. But [Jón Schone], aka Proper Printing on YouTube, got the idea for his belt-drive extruder from seeing how filament manufacturers handle their products. His design is a scaled-down version of that, and uses a pair of very small timing belts that run on closely spaced gears. The gears synchronize the movement of the two belts, with the filament riding in the very narrow space between the belts. It’s a simple design, with the elasticity of the belt material eliminating the need for spring pre-loading of the drive gears.

Simple in design, but not the easiest execution. The video below tells [Jón]’s tale of printing woe, from using a viscous specialty SLA resin that was really intended for a temperature-controlled printer, to build tank damage. The completed extruder was also a bit too big to mount directly on the test printer, so that took some finagling too. But at the end of the day, the idea works, and it looks pretty cool doing it.

As for potential advantages of the new design, we suppose that remains to be seen. It does seem like it would eliminate drive gear eccentricity, which we’ve seen cause print quality issues before.

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Concrete With 3D Printed Foam Forms

December 20, 2021 by 17 Comments

The latest 3D printing application?  Forming concrete. That’s according to a team at ETH Zurich who claims that construction with foam forms cuts concrete usage up to 70%. It also offers improved insulation properties. You can see a video about the process, below.

Typical concrete work relies on a form often made with wood, steel, or plastic. That’s easy to do, but hard to make complex shapes. However, if you can create complex shapes you can easily put material where it adds strength and omit material where it doesn’t carry load. Using a robotic-arm 3D print technique, the researchers can lay out prefabricated blocks of foam that create forms with highly complex shapes. Continue reading “Concrete With 3D Printed Foam Forms” →

Wire ECM built from an Ender 3

Simple Mods Turn 3D Printer Into Electrochemical Metal Cutter

December 17, 2021 by 30 Comments

We’re not aware of any authoritative metrics on such things, but it’s safe to say that the Ender 3 is among the most hackable commercial 3D printers. There’s just something about the machine that lends itself to hacks, most of which are obviously aimed at making it better at 3D printing. Some, though, are aimed in a totally different direction.

As proof of that, check out this Ender 3 modified for electrochemical machining. ECM is a machining process that uses electrolysis to remove metal from a workpiece. It’s somewhat related to electric discharge machining, but isn’t anywhere near as energetic. [Cooper Zurad] has been exploring ECM with his Ender, which he lightly modified by replacing the extruder with a hypodermic needle electrode. The electrode is connected to a small pump that circulates electrolyte from a bath on the build platform, while a power supply connects to the needle and the workpiece. As the tool traces over the workpiece, material is electrolytically removed.

The video below is a refinement of the basic ECM process, which [Cooper] dubs “wire ECM.” The tool is modified so that electrolyte flows down the outside of the needle, which allows it to enter the workpiece from the edge. Initial results are encouraging; the machine was able to cut through 6 mm thick stainless steel neatly and quickly. There does appear to be a bit of “flare” to the cut near the bottom of thicker stock, which we’d imagine might be mitigated with a faster electrolyte flow rate.

If you want to build your own Ender ECM, [Cooper] has graciously made the plans available for download, which is great since we’d love to see wire ECM take off. We’ve covered ECM before, but more for simpler etching jobs. Being able to silently and cleanly cut steel on the desktop would be a game-changer.

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