Sand Plotter Built With 3D Printer Parts

January 13, 2021 by Lewin Day 23 Comments

Sand plotters are beautiful machines. They can make endless patterns, over and over again, only to wipe away their own creation with each new pass. Having seen the famous Sisyphus sand sculpture online, [Simon] decided to make his own.

The build came together quickly, thanks to [Simon]’s well-stocked workshop and experience with CNC motion platforms. The frame was built out of wood, with a combination of hand-cut and lasercut parts. After fabric-wrapping the outer rim turned out poorly, rope was substituted instead for a stylish, organic look. LEDs were installed inside to light the sand for attractive effect. The metal ball is moved through the sand via a magnet attached to an XY platform mounted on the back of the table. The platform is built out of old 3D printer parts, with a Creality CR10S Pro chosen for its ultra-quiet stepper drivers. Initial attempts to make the system near-silent were hung up by the crunching sound of the ball rolling over the sand; this was fixed by instead mounting the ball on a foam pad. While the ball is now dragged instead of rolling, the effect is one of blissful quiet instead of crunching aggravation.

The final build is incredibly attractive, and something we’d love to have as a coffee table as a conversation piece. We’ve seen [Simon]’s work around here before, too – with the water-walking RC car a particular highlight. Video after the break.

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3D Printing In Five Axes Makes The World Flat

January 12, 2021 by Al Williams 23 Comments

Just when you thought your 3D printer was hot stuff, along comes a 5D printer. Two doctoral students at Penn State want to add two more axes to get rid of overhangs. This means that instead of supports or breaking objects into pieces, the printer simply orients the print so each region of the part is printing as if it were flat. Of course, 5D printers aren’t really new, even though you don’t hear much about them. However, the paper details a new algorithm that eliminates manually defining print regions and rotations.

You do this all the time manually when you’re setting the print up. For example, if you want to print a letter T, you could print it with supports under the cross pieces or flip it upside down and print it with no support at all. The difference here is the printer can flip the workpiece itself to different angles and can change it on the fly during printing. The printer might print the shaft of the T, rotate it to draw half of the crossbar, then rotate it 180 degrees to print the other half. In all three zones, the print head is depositing materials flat with no overhang. In a simple case like a T that doesn’t really require a special machine or an algorithm, but in the general case, you often can’t just rotate a model to avoid using supports.

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Industrial Stack Light Keeps An Eye On Prusa Mini

January 9, 2021 by Tom Nardi 17 Comments

When most people want to keep tabs on what their 3D printer is up to while they’re out and about, they’ll install OctoPrint on a Pi and be done with it. But what if you’re just on the other side of the room? Inspired by the stack lights used on factory floors, [Jeff Glass] decided to add a similar system to his Prusa Mini so he could see what it’s up to at a glance.

It turns out you can get these lights pretty cheaply online from the usual retailers, and as [Jeff] explains in the video after the break, driving them is about as easy as it gets. Rather than being some kind of addressable device, they generally have a single common 12 or 24 volt DC wire and ground lines for each color. With a USB controlled relay board, kicking on the appropriate light is simple from your operating system of choice.

What ended up being a bit harder was finding out what the Prusa Mini was up to. The printer offers up a simple status web page, but it has a few oddball quirks that make it difficult to scrape; such as presenting a little pop-up message that you have to manually close each time you load the page. But after spending some time with the powerful Selenium library for Python, he was able to create a script that worked its way through the UI and pulled the relevant status messages. Obviously the resulting code is Prusa specific, but the general concept would work on other printers assuming you can find a reliable way to pull the device’s current status.

After coming up with a wall mounted enclosure for the electronics that doubles as a mount for the light itself, [Jeff] can now see if his printer needs attention from clear across the room. An especially nice feature when the printer is all buttoned up inside of its enclosure.

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Turning A CMM Into A 3D Printer

January 6, 2021 by Matthew Carlson 47 Comments

There are two paths to owning a 3D printer: purchasing one or crafting your own 3D printer designed to your own exacting specifications. [Roetz 4.0] has decided to go this latter route and converted a 1.3-ton air-bearing Coordinate-measuring machine (CMM) into an FDM 3D printer. (Video, embedded below.)

A CMM is a tool used to precisely measure the geometry of an object via gently lowering a calibrated probe. We’ve seen scratch build printers before, but this particular build benefits from having the CMM machinery and its 18 air bearings. The CMM head is moved by [Roetz 4.0]’s own custom system, but it takes advantage of the bearings. After some careful CAD planning as well as a fair bit of milling, lathing, and prototyping, he had buttery smooth controlled motion.

With an off the shelf driver board wired together with a large red button, he was ready for a maiden test print. A determination to finish before the year was out pushed things along. There are still a few quirks to fix, like the hole in the air drying system but those can be tackled next year. Ultimately, we think the results are stunning and it was a journey we were glad to go on with [Roetz 4.0]. The final episode of the series is after the break.

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Heat Turns 3D Printer Filament Into Springs

January 6, 2021 by Donald Papp 11 Comments

The next time you find yourself in need of some large-ish plastic springs, maybe consider [PattysLab]’s method for making plastic springs out of spare filament. The basic process is simple: tightly wind some 3D printer filament around a steel rod, secure it and wrap it in kapton tape, then heat it up. After cooling, one is left with a reasonably functional spring, apparently with all the advantages of annealed plastic.

The basic process may be simple, but [PattysLab] has a number of tips for getting best results. The first is to use a 3D-printed fixture to help anchor one end of filament to the steel rod, then use the help of an electric drill to wind the filament tightly. After wrapping the plastic with kapton tape (wrap counter to the direction of the spring winding, so that peeling the tape later doesn’t pull the spring apart), he suspends it in a pre-heated oven at 120 C for PLA and 160 C for PETG. How long does it stay in there? [PattysLab] uses the following method: when the spring is wound, he leaves a couple inches of filament sticking out to act as a visual indicator. When this segment of filament sags down, that’s his cue to begin the retrieval process. After cooling, the result is a compression or extension spring, depending on how it was wound before being heated.

[PattysLab] shared a short video on this Reddit post that shows both springs in action, and the process is all covered in the video, embedded below.

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Burned Out SKR E3 Mini Gets New Stepper Driver

January 5, 2021 by Tom Nardi 19 Comments

It didn’t take long to figure out that a dead X axis and an message saying “TMC CONNECTION ERROR” meant that one of the stepper drivers on the SKR E3 Mini 3D printer control board had released the magic smoke. Manufacturer BigTreeTech replaced the board under warranty, and the printer was back up and running in short order. But instead of tossing it in the trash, [Simon] wondered how hard it would be to repair the dead board.

Removing the original stepper driver IC.

The short answer is, not very hard. There was no question as to which of the four TMC2209 drivers was shot, since the X motor was the only one experiencing a problem. The drivers unfortunately aren’t socketed on this board, but after a little kiss with the hot air, the old chip was off.

[Simon] didn’t have any spare TMC2209 chips, but the TMC2208 has the same pinout and is a drop-in replacement. The TMC2208 is rated for a bit less current, but it shouldn’t be a problem under normal circumstances.

Other than the stepper connector getting a little toasty during the installation, the swap went off without a hitch and the board was up and running again. [Simon] ended up putting the now repaired SKR E3 Mini in his Ender 3; a nice 32-bit upgrade compared to the ATmega1284 that was originally running the show. Though in the past, he’s managed to squeeze a bit more performance out of the older 8-bit board as well.

Xolography: A Method To Improve The Accuracy Of Volumetric 3D Printing

January 4, 2021 by Maya Posch 7 Comments

Over the past years, additive manufacturing (AM) has become a common tool for hackers and makers, with first FDM and now SLA 3D printers becoming affordable for the masses. While these machines are incredibly useful, they utilize a slow layer-by-layer approach to produce objects. A relatively new technology called Volumetric Additive Manufacturing (VAM) promises to change all that by printing the entire object in one go, and according to a recent article in Nature, it just got a big resolution boost.

The concept is similar to SLA printing, but instead of curing the resin by projecting a 2D image of the current layer into the container, VAM uses multiple lasers to create intersecting points within the liquid. After exposing the resin to this projection for several seconds, the 3D model is built all at once. Not only is this far faster, but it removes the need for support materials and even a traditional build plate is unnecessary.

Visualization of the dual-color printing process as used by Regehly et al. (Credit: Nature)

Up till now the resolution and maximum object size of VAM has left a lot to be desired, but in this new research by Regehly et al. claim to have accomplished a feature resolution of ‘up to 25 micrometers’ and a solidification rate of ‘up to 55 cm³/s’. They used two crossing laser beams of different wavelengths, one to form the ‘light sheet’ (blue in the graphic) and a second beam (in red) to project the slide onto this light sheet. They refer to this technique as ‘xolography’, as a mesh-up of ‘holo’ (Greek for ‘whole’) and the ‘X’ shape formed by the crossing laser beams.

Key to making this work is the chemistry of the resin: the first wavelength excites the molecules called DCPI (Dual-Color Photo Initiators) that are dissolved in the resin. The second wavelength when hitting the same molecules initiates the resin polymerization process. The object pictured at the top of the page was a test print; producing such a design on a traditional 3D printer would have required a considerable amount of difficult to remove support material.

While this is obviously not a technology hobbyists will be using to replace their FDM and SLA printers with any time soon, there are still many companies and institutes working on various VAM technologies and approaches. As more and more of the complexities and challenges are dealt with, who knows when VAM may become a viable replacement for at least some SLA applications?

Thanks to [Qes] for the tip.