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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Ask Hackaday: Are Extruders The Only Feasible Tools For Toolchanging?

December 13, 2021 by Donald Papp 34 Comments

Toolchanging in 3D printers is no longer something from the bleeding edge; it’s going mainstream. E3D has a high-quality kit for a toolchanger and motion system, our own Joshua Vasquez has shared details about the open-source toolchanging Jubilee design, and just recently Prusa3D formally announced the Prusa XL, which promises toolchanging with up to five different extruders.

It’s safe to say toolchanging on 3D printers has stepped to the front, but what comes next? What kind of tools other than extruders make sense on a 3D printer?

First, let’s explain what makes separate extruders such fantastic tools. Being able to change extruders on-demand during a print enables things like true multi-material printing. Printing in more than one color or material will no longer be done by pushing different filaments through a single nozzle, which limits a print to materials that extrude under similar conditions and temperatures. Toolchanging means truly being able to print in multiple materials, even if they have different requirements, because each material has its own extruder. That’s a clear benefit, but what about tools other than extruders?

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Image Credit: https://3dp.se/2018/04/17/3dmeetup-lockade-entusiaster-i-alla-aldrar/

Remembering Sanjay Mortimer, Pioneer And Visionary In 3D Printing

December 1, 2021 by Sonya Vasquez 25 Comments

Over the weekend, Sanjay Mortimer passed away. This is a tremendous blow to the many people who he touched directly and indirectly throughout his life. We will remember Sanjay as pioneer, hacker, and beloved spokesperson for the 3D printing community.

If you’ve dabbled in 3D printing, you might recall Sanjay as the charismatic director and co-founder of the extrusion company E3D. He was always brimming with enthusiasm to showcase something that he and his company had been developing to push 3D printing further and further. But he was also thoughtful and a friend to many in the community.

Let’s talk about some of his footprints.

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Fifty Shades Of Brown: 3D Printing With Sugar

November 25, 2021 by Dave Rowntree 20 Comments

[Norbert Heinz] has been busy for the 2021 Hackaday Prize entry, working on the design of a direct granule extruder for 3D printing with waste materials, or materials that are not provided in the form of a filament. Sugar is pretty common in most households, so since that’s already available in granular form, [Norbert] gave 3D printing with granulated sugar a try. (Video, embedded below.)

[Editor’s note: He earned fifth place for this one! Well, not the sugar in particular, but the overall great work on granular extruders.]

Success was somewhat variable, as the gloopy material is notoriously fickle to work with, but the setup did produce some structures that stayed in one piece, at least for a while. Initially [Norbert] tried it real slow, effectively printing with the liquified sweet stuff, by dragging a molten blob of it around on the end of the extruder nozzle. Whilst this did work, the resulting print resolution did leave something to be desired. The next thing tried was increased print speed. This produced clearer prints, as the sugar did not have time to caramelise, or form a noticeable blob, but as soon as the bed started to cool, it caused it to crack badly.

Going slow seemed to be the way forward, as more time to cool may have reduced the stresses in the structure due to the increased cooling time. But anyway, the way we see it, is it’s fun trying, and if it fails, you can just eat it, so long as you disregard all that food safety stuff anyway.

[Norbert] documents the granule extruder journey on the project Hackaday.io page, so it should be straightforward enough to duplicate this is you were so inclined.

We’ve covered a few sugary hacks before; Need a renewable bed adhesive? out of glue stick? try sugar as a bed adhesive! Printing in gloopy, sloppy materials is nothing new at all, we covered it nearly ten years ago.

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Spinning Threads Put The Bite On Filament In This Novel Extruder Design

October 20, 2021 by Dan Maloney 29 Comments

When it comes to innovation in FDM 3D printing, there doesn’t seem to be much room left to move the needle. Pretty much everything about filament printing has been reduced to practice, with more or less every assembly available off the shelf. Even the business end — the extruder — is so optimized that there’s not much room left for innovation.

Or is there? The way [David Leitner] sees it, there is, which is why he built this rolling-screw extruder (if you can get to the Thingiverse link, [David] cross-posted on reddit, too). Standard extruders work on the pinch-roller principle, where the relatively soft filament is fed past a spring-loaded gear attached to a stepper motor. The stepper rotates the gear, which either advances the filament into or retracts it from the hot end. [David]’s design instead uses a trio of threaded rods mounted between two rings. The rods are at an angle relative to the central axis of the rings, forming a passage that’s just the right size for the filament to fit in. When the rings spin, the threads on the rods engage with the filament, gripping it around its whole circumference and advancing or retracting it depending on which way it’s spinning. The video below shows it working; we have to admit it’s pretty mesmerizing to watch.

[David] himself admits there’s not much advantage to it, perhaps other than a lower tendency to skip since the force is spread over the entire surface of the filament rather than just a small pinch point. Regardless, we like the kind of thinking that leads to something like this, and we’ll bet there are probably unseen benefits to it. And maybe the extruder actually is a place for innovation after all; witness this modular nozzle swapping system.

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Inconsistent layer heights in a 3D print

An Easy Fix For Inconsistent Layers In Cheap 3D Printers

October 17, 2021 by Dan Maloney 26 Comments

If there’s one thing you can say about [Stefan] from CNC Kitchen, it’s that he’s methodical when he’s working on an improvement to his 3D printing processes, or when he’s chasing down a problem with a printer. Case in point: this root-cause analysis of extrusion inconsistencies with an entry-level 3D printer.

The printer in question is a Cetus MK3, a printer that found its way onto many benches due to its ridiculously low price and high-quality linear bearings. Unfortunately, there’s still a lot to be desired about the printer, and its tendency for inconsistent layers was chief among [Stefan]’s gripes. Such “blubbiness” can be pinned on any number of problems, but rather than guess, [Stefan] went through a systematic process of elimination to find the root cause. We won’t spoil the ending, but suffice it to say that the problem was subtle, and could probably be the cause of similar problems with other printers. The fix was also easy, and completely mechanical — just a couple of parts to replace. The video below shows the whole diagnosis process, as well as the before and after comparisons. [Stefan] also teases an upcoming treatment on how he converted the Cetus from the stock proprietary control board, which we’re interested in seeing.

If you haven’t checked out any of [Stefan]’s other 3D printing videos, you really should take a look. Whether it’s vibration damping with a concrete paver, salt annealing prints for strength, or using finite element analysis to optimize infills, he’s always got an interesting take on 3D printing.

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Retrotechtacular: 3D-Printed Buildings, 1930s Style

October 6, 2021 by Dan Maloney 35 Comments

Here we are in the future, thinking we’re so fancy and cutting edge with mega-scale 3D printers that can extrude complete, ready-to-occupy buildings, only to find out that some clever inventor came up with essentially the same idea back in the 1930s.

The inventor in question, one [William E. Urschel] of Valparaiso, Indiana, really seemed to be onto something with his “Machine for Building Walls,” as his 1941 patent describes the idea. The first video below gives a good overview of the contraption, which consists of an “extruder” mounted on the end of a counterweighted boom, the length of which determines the radius of the circular structure produced. The boom swivels on a central mast, and is cranked up manually for each course extruded. The business end has a small hopper for what appears to be an exceptionally dry concrete or mortar mix. The hopper has a bunch of cam-driven spades that drive down into the material to push it out of the hopper; the mix is constrained between two rotating disks that trowel the sides smooth and drive the extruder forward.

The device has a ravenous appetite for material, as witnessed by the hustle the workers show keeping the machine fed. Window and door openings are handled with a little manual work, and the openings are topped with lintels to support the concrete. Clever tools are used to cut pockets for roof rafters, and the finished structure, complete with faux crenellations and a coat of stucco, looks pretty decent.

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