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

December 23, 2021 by Dan Maloney 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 Al Williams 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” →

Simple Mods Turn 3D Printer Into Electrochemical Metal Cutter

December 17, 2021 by Dan Maloney 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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Tesla Model S Gets Boost With Jet Engine Upgrade

December 16, 2021 by Matthew Carlson 72 Comments

Tesla is well known for making cars that can accelerate quickly, but there’s always room for improvement. [Warped Perception] decided that his Tesla Model S P85D needed that little bit of extra oomph (despite the 0-60 MPH or 0-97 km/h time of 3.1 seconds), so he did what any sensible person would: add three jet turbines to the back of his car.

The best part of this particular build is the engineering and fabrication that made this happen. With over 200 pieces and almost all personally fabricated, this is a whirlwind of a build. The control panel is first, and there’s a particularly clever technique of 3D printing the lettering directly onto the control panel for the flat stuff. Then for the pieces with angles that would prevent the head from moving freely, he printed onto a plastic sheet in reverse, applied glue, then stuck the letters to the plate as a sheet. A top layer of clear coat ensures the letters won’t come off later.

Using a 3D printer to apply lettering on the control panel.

He installed the control electronics in the trunk with wiring strung from the car’s front to the rear. Three Arduinos serve as controllers for the jets. Afterward, came the bracket to hold the engines and attach it to the car’s underside. Unfortunately, supplies were a little hard to come by, so he had to make do with what was on hand. As a result it didn’t come out as strong as he would have hoped, but it’s still pretty impressive.

[Warped Perception] does a few tests before taking it out on the road. Then, he shifted the car into neutral and could drive the car solely on jet power, which was one of his goals. While we don’t love the idea of testing a jet engine on public roads, it certainly would discourage tailgaters.

Next, he finds a quieter road and does some speed tests. Unfortunately, it was drizzling, and the pavement was damp, putting a damper on his 0-60 standing times. Electric-only he gets 4.38 seconds, and turning on the jets plus electric shaves that down to 3.32 seconds. Overall, an incredible build that’s sure to draw a few curious glances whenever you’re out on the town.

If you’re looking to upgrade your Tesla, perhaps instead of jet engines, you might opt for a robot to plug it in for you?

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Resin Stacking Proves Messy And Difficult

December 12, 2021 by Lewin Day 15 Comments

3D printers are typically the tool you use when you want a one-off quick prototype. However, more and more, they’re being used to produce things in quantity. [Uncle Jessy] decided to try out the resin stacking technique in order to quickly produce many figurines on his resin printer. However, not everything went exactly to plan.

The technique is simple. The idea is to produce many copies of an object in a single continuous print on a resin 3D printer. To achieve this, the object is cloned many times, and scaffolding is created to allow the stacking of multiple objects on top of each other. This must be done carefully to avoid ruining the geometry of the object, and similarly to support material, uses more resin in the process.

[Uncle Jessy] experimented several times, but ran into multiple issues with the process when trying to print out some small Magneto figurines. An initial experiment using a raft failed when the print fell off the build plate. With the raft removed, the second print failed as the scaffolding didn’t print quite right. Further tweaks and beefing up the scaffold improved things, and [Jessy] managed to print 93 figurines in a single operation.

It’s a useful technique if you want to print a ton of models on a resin printer in as short a time as possible. However, expect to spend plenty of resin as you refine the technique. You’ll also need a big wash tank to clean the prints during post-processing. Video after the break.

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Customize These 3D Printed Cases

December 12, 2021 by Al Williams 27 Comments

Building something, of course, requires your electronics skills. But packaging it is often an exercise in mechanics. You can buy off the shelf, of course, but sometimes it is hard to find just the right enclosure. You probably have a 3D printer, too, but sometimes 3D printing an entire case can be time consuming and isn’t always completely attractive. Enter [Johannes-Bosch] and Fusion 360. These 3D printed frames assemble into boxes and are easy to customize. The panels are aluminum, although we imagine you could substitute wood, acrylic, or even a 3D printed sheet of plastic, if you wanted to.

The video below shows some examples. If your German isn’t up to snuff, ask YouTube to automatically translate the subtitles and you’ll get the idea.

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Vacuum Forming With 3D Printer Filament

December 11, 2021 by Tom Nardi 17 Comments

Even if they don’t have one themselves, we’d wager the average Hackaday reader is at least vaguely aware of how a vacuum former works on a fundamental level. You heat up a plastic sheet until it’s soft, then use a vacuum pump to pull the ductile material down onto an object and hold it there while it cools off. It’s easy to build a vacuum forming rig yourself, but small commercial units are cheap enough that it might not be worth your time. If everything goes to plan, the technique is a quick and effective way of duplicating items around the home and shop.

But we were recently tipped off to a variation of this classic technique that’s certainly worth further research. As demonstrated in a recent video, [Nathan Martinez] shows how 3D printed sheets can be used in place of the 5″ x 5″ squares of thermoplastic film that his imported vacuum former was designed to use. It’s easy enough to do: just model up a square with the appropriate 2D dimensions in your CAD package of choice, and extrude it to a height of about .5 mm.

A printed mesh pattern could be used to form custom shaped filters or strainers.

So what’s the advantage? Well for one thing, it’s cheaper. Though admittedly, not by much. Going rate on Amazon seems to be about 90 cents per sheet for the real stuff, and some back of the envelope math shows the printed version coming in at around 30 cents given nominal filament costs. Whether or not those savings are worth the extra effort is certainly debatable.

But that’s not really the most interesting part. With printed sheets loaded into the vacuum former, you’ve got access to a much wider array of materials to work with. For example, [Nathan] shows off some very interesting flexible pieces he was able to produce using sheets of TPU. You can also experiment with different surface textures. These can not only be used to give your vacuum formed pieces a bit of interesting visual flair, but could actually have some practical applications. In the video we see how a printed mesh could be formed over a piece to create a conformal air vent or filter.

To be sure, there’s some room for improvement here. Not all the pulls were successes, and [Nathan] says getting the printed sheets up to the proper temperature can be tricky. But when it works, it works quite well, and we think there could be some untapped potential in this unexpected melding of new and old methods of at-home plastic production.

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