Build Your Own Concrete 3D Printer

October 25, 2022 by Al Williams 18 Comments

We didn’t notice [Nikita]’s post about building a concrete 3D printer, a few months ago, but the idea seems sound: build a basic CNC XY axis and then add a mortar pump and hose to deposit concrete. The video, below, shows the machine in operation.

While it looks interesting, there is essentially no real Z-axis, so this would be limited to some sort of relatively thin forms unless you, perhaps, did a few layers and then further lifted the machine. We also assume wet concrete won’t bridge at all. Still, this might be an interesting project, especially if you have a spare CNC XY axis floating around.

If you buy everything, though, you are looking at an estimated cost of around $7,000 USD. We presume there is enough weight in the concrete that a conventional 3D printer probably isn’t going to cut it. We did wonder, though, if there would be any merit to connecting a conventional plastic-extruding nozzle to be able to lay down support for the concrete.

This might be a good jumping-off point for a more sophisticated machine. In particular, [Nikita] points out that a progressive cavity pump with a variable frequency drive is ideal, because it allows you to vary the extrusion rate and provides a steady flow of concrete. Armed with that knowledge, you could probably figure out the rest pretty easily if you’ve ever built a 3D printer or CNC machine.

Not the first concrete printer we’ve seen, of course. The one we saw before was capable of some pretty amazing things.

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DIY Heat-Set Insert Press Says Complicated = Comfort

October 23, 2022 by Donald Papp 16 Comments

Heat-set inserts are a great way to embed mechanically-strong, threaded parts into a 3D print. For installation, all that is required is an economical soldering iron; something most of us already have.

The carriage and counterweight use a v-wheel gantry, GT2 belt, and other common hardware.

That’s fine for a handful of occasional inserts, but when a large number need to be inserted reliably and cleanly, something a little more refined is called for. That’s where [virchow]’s threaded insert press design comes in. It adds 3D-printed parts to an aluminum extrusion frame to create a press that smoothly lowers a soldering iron directly up and down, with minimal effort by the user.

The holder for the soldering iron is mounted to a small v-wheel gantry that rides along the vertical extrusion. The gantry features a counterweight to take care of resetting the position of the iron. [Virchow] admits that the design could be considered unnecessarily complicated (hence the “UC” in the name) but on the other hand, there’s nothing like doing a hundred or so inserts to make one appreciate every bit of comfort and stability.

Heat-set inserts aren’t difficult to use, but a little technique goes a long way. Spend a few minutes reading Joshua Vasquez’s guide on the optimal way to use them in 3D-printed parts to make sure yours not only go in straight but end up looking great as well.

ERRF 22: Baby Belt Promises Infinite Z For Under $200

October 23, 2022 by Tom Nardi 20 Comments

Hackaday has been reporting on belt printers for around a decade now, since MakerBot released (and then quickly pulled) an automated build platform for their very first Cupcake printer. Turns out that not only has the concept been difficult to pull off from a technical perspective, but a murky patent situation made it tricky for anyone who wanted to bring their own versions to market. For a long time they seemed like the fusion reactors of desktop 3D printing — a technology that remains perennially just outside of our grasp.

But finally, things have changed. The software has matured, and there are now several commercial belt printers on the market. The trick now, as it once was for traditional desktop 3D printing, is to bring the costs down. Enter the Baby Belt, created by [Rob Mink]. This open-source belt printer relies on light-duty components and a largely 3D printed structure to get the price point down, though some will find its diminutive dimensions a bit too limiting…even if one of its axes is technically infinite.

If you’ve already got a printer and filament to burn, [Rob] is selling the part kit for just $130 USD. But even if you opt for the full ready-to-build kit, it will only set you back $180. Considering even the cheapest belt printers on the market now have a sticker price of more than $500, that’s an impressive accomplishment.

Of course, it’s hard to compare the Baby Belt with anything else on the market. For one thing, save for a few metal rods, its frame is made almost entirely from 3D-printed parts. Rather than the NEMA 17 stepper motors that are standard on even the cheapest of traditional desktop 3D printers, this little fellow is running on the dinky 28BYJ-48 steppers that you’d expect to find in a cheap toy. Then again, considering the printer only offers 85 x 86 mm in the X and Y axis, the structure and motors don’t exactly need to be top of the line.

What really sets this machine apart is the belt — while we’ve seen other makers go all out with their belt material, [Rob] has come up with an impressively low-tech solution. It’s a simple stack-up of construction paper, carpet tape, and fabric that you could probably put together with what you’ve got laying around the house right now.

Between that outer cloth layer and the printed frame, the Baby Belt offers a lot of room for customization, something which was on clear display at the 2022 East Coast RepRap Festival. The machines dotted several tables on the show floor, and you could tell their builders had a lot of fun making each one their own

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Build This Halloween-Themed TensEGGrity Sculpture

October 21, 2022 by Lewin Day 5 Comments

Tensegrity sculptures are fun things, and often sold as office desk toys or scientific novelties. You can build your own too, and [seabirdhh] has whipped up a fun holiday-themed version.

The first part to build is the egg-hat-stand. This consists of the base of the structure, with the “hat” of the egg character hanging in the center. The other half of the structure is built separately, with the rest of the “egg head” sitting in a cup in the bottom of the upper structure. A series of nylon threads are then tied between the components. These can then be tensioned to give the structure its shape, allowing the egg’s “hat” to hover above its “head”. [seabirdhh] passes the nylon threads through small pieces of rubber that allow the tension to be adjusted just right. Too little and the structure falls down, but too much, and it will bend over time. Tuning it carefully is key.

It’s a fun build, and a cheap way to experiment with tensegrity concepts at home. You can even use these same techniques to build a quadcopter, or apply them in the world of LEGO. Video after the break.

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A 3D Printer With Quadruple The Output

October 19, 2022 by Bryan Cockfield 8 Comments

While the polygraph is colloquially associated with pseudoscientific lie detector tests, the actual invention of the first polygraph was designed to mechanically duplicate the pen strokes of someone writing. Famously, a polygraph was used by former US President Thomas Jefferson in his “modern office”, a replica of which still sits in the Smithsonian museum. Few of us have a need for a pen-based polygraph anymore, but inspiration from the centuries-old invention can still be gleaned from the machine, like in this 3D printer which can output four identical prints at once.

The printer is a Core XY design with four separate print heads, which are all locked together. The printer behaves as if there is a single print head which keeps it simpler than it otherwise could be. Some extra consideration needs to be paid to the print bed to ensure it’s level and flat, and it also includes a unique Z-axis designed to prevent Z-banding from poor quality leadscrews. It has a fairly wide print area, but a noticeable restriction is that it’s essentially quartered, so while it can produce many parts at once, it can’t produce a single part that uses the entire area of the print bed.

Every printed part used to make this printer was designed by [Rick] in OpenSCAD. He also built a custom electronics board with the printer drivers, and all other associated circuitry in KiCad. For anyone who prints large volumes of parts, this might be just the trick to increase output without having to manage more printers. If you already have more printers and need an easier way to manage them all, take a look at this dedicated Raspberry Pi set up to do just that.

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3D Printering: Managing Multiple Printing Profiles

October 18, 2022 by Al Williams 7 Comments

I know people who have 3D printers that are little more than appliances. They buy it, they print with it, and they don’t change much of anything. That doesn’t describe me and, I’m guessing, it doesn’t describe you either. This does lead to a problem, though, when it comes to slicers. You have to keep changing profiles and modifying them. It can be hard to keep things straight. For example, if you have profiles for different nozzles, you get to make a choice: keep one profile and edit the parts that change, or keep multiple profiles and any common changes have to be propagated to the other profiles.

Part of the reason I want to manage multiple profiles has to do with this mystery object…

I’ve long wanted to create a system that lets me have baseline profiles and then just use specific profiles that change a few items in the baseline. Turns out, I didn’t need to do it. Prusa Slicer and its fork, SuperSlicer, have the capability already. Both of these, of course, are based on Slic3r, but the scripting languages are different and what I’m doing does require G-code scripting. The problem is, this capability is not documented very well and the GUI doesn’t really support it directly, which requires a little sidestepping. I’ll show you how I have things set up and where the limitations are. If you want to try your hand at it, I highly suggest you backup your configuration directory or switch to a new one.

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3D Printing With A Drone Swarm?

October 18, 2022 by Dave Rowntree 14 Comments

Even in technical disciplines such as engineering, there is much we can still learn from nature. After all, the endless experimentation and trials of life give rise to some of the most elegant solutions to problems. With that in mind, a large team of researchers took inspiration from the humble (if rather annoying) wasp, specifically its nest-building skills. The idea was to explore 3D printing of structures without the constraints of a framed machine, by mounting an extruder onto a drone.

As you might expect, one of the most obvious issues with this attempt is the tendency of the drone’s to drift around slightly. The solution the team came up with was to mount the effector onto a delta bot carrier hanging from the bottom of the drone, allowing it to compensate for its measured movement and cancel out the majority of the positional error.

The printing method relies upon the use of two kinds of drone. The first done operates as a scanner, measuring the print surface and any printing already completed. The second drone then approaches and lays down a single layer, before they swap places and repeat until the structure is complete.

Multiple drones can print simultaneously, by flying in formation. Prints were demonstrated using a custom cement-like material, as well as what appeared to be expanding foam, which was impressive feat to say the least.

The goal is to enable the printing of large, complex shaped structures, on any surface, using a swarm of drones, each depositing whatever material is required. It’s a bit like a swarm of wasps building a nest, into whatever little nook they come across, but on the wing.

We’ve been promised 3D printed buildings for some time now, and while we’re not sure this research is going to bring us any closer to living in an extruded house, we’re suckers for a good drone swarm here at Hackaday.

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