See This Hybrid Approach To Folded 3D Printed Mechanisms

July 27, 2021 by Donald Papp 6 Comments

3D printers are quite common nowadays, but we’re still far from exhausting new ideas to try with them. [Angus] of [Maker’s Muse] recently got interested in 3D printing small mechanical assemblies that can be put together by folding them up, and also depend on folding linkages for the moving parts. (Video, embedded below.) The result would be lightweight, functional assemblies that would be simple to manufacture and require very few parts; but how to make the hinges themselves is the tricky part. As a proof-of-concept, [Angus] designed a clever steering linkage that could be printed flat and folded together, and shows his work on trying to make it happen.

[Angus] points out that that 3D-printed hinges have a lot of limitations that make then less than ideal for small and lightweight assemblies. Printing hinge pieces separately and assembling after the fact increases labor and part count, and print-in-place hinges tend to have loose tolerances. A living hinge made from a thin section of material that folds would be best for a lightweight assembly, but how well it works depends a lot of the material used and how it is made.

[Angus] tries many different things, and ultimately decided on a hybrid approach, combining laser cutting with 3D printing to create an assembly that consists of a laser-cut bottom layer with 3D printed parts on top of it to create a durable and lightweight device. He hasn’t quite sorted it all out, but the results show promise, and his video is a fantastic peek at just how much work and careful experimentation can go into trying something new.

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Open Source CAM Software In The Browser

March 1, 2021 by Danie Conradie 24 Comments

3D printers, desktop CNC mills/routers, and laser cutters have made a massive difference in the level of projects the average hacker can tackle. Of course, these machines would never have seen this level of adoption if you had to manually write G-code, so CAM software had a big part to play. Recently we found out about an open-source browser-based CAM pack created by [Stewert Allen] named Kiri:Moto, which can generate G-code for all your desktop CNC platforms.

To get it out of the way, Kiri:Moto does not run in the cloud. Everything happens client-side, in your browser. There are performance trade-offs with this approach, but it does have the inherent advantages of being cross-platform and not requiring any installation. You can click the link above and start generating tool paths within seconds, which is great for trying it out. In the machine setup section you can choose CNC mill, laser cutter, FDM printer, or SLA printer. The features for CNC should be perfect for 90% of your desktop CNC needs. The interface is intuitive, even if you don’t have any previous CAM experience. See the video after the break for a complete breakdown of the features, complete with timestamp for the different sections.

All the required features for laser cutting are present, and it supports a drag knife. If you want to build an assembly from layers of laser-cut parts, Kiri:Moto can automatically slice the 3D model and nest the 2D parts on the platform. The slicer for 3D printing is functional, but probably won’t be replacing our regular slicer soon. It places heavy emphasis on manually adding supports, and belt printers like the Ender CR30 are already supported.

Kiri:Moto is being actively improved, and it looks as though [Stewart] is very responsive to community inputs. The complete source code is available on GitHub, and you can run an instance on your local machine if you prefer to do so. Continue reading “Open Source CAM Software In The Browser” →

3D Printer? Laser Cutter? CNC? Yes, Please

February 10, 2021 by Al Williams 60 Comments

Most of us have, or, would like to have a 3D printer, a laser engraver, and a CNC machine. However, if you think about it naively, these machines are not too different. You need some way to move in the XY plane and, usually, on the Z axis, as well.

Sure, people mount extruders on CNCs, or even lasers or Dremel tools on 3D printers. However, each machine has its own peculiarities. CNCs need rigidity. 3D printers should be fast. Laser engravers and CNCs don’t typically need much Z motion. So common sense would tell you that it would be tough to make a machine to do all three functions work well in each use case. [Stefan] thought that, too, until he got his hands on a Snapmaker 2.0.

As you can see in the video below, the machine uses different tool heads for each function. The motion system stays the same and, curiously, there are three identical linear motion modules, one for each axis.

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Cleaner Laser Cutting With A 3D-Printed Nozzle

November 25, 2020 by Donald Papp 24 Comments

[Nervous System] does a lot of laser cutting, and [Jesse] shared a fascinating experimental improvement to their laser cutter that consists of a 3D-printed nozzle for cleaner cuts. You can see the results for yourself above, where the difference between the two cuts is striking.

[Jesse]’s modification doesn’t affect the laser beam itself; it is an improvement on the air assist, which is the name for a constant stream of air that blows away smoke and debris as the laser burns and vaporizes material. An efficient air assist is one of the keys to getting nice clean laser cuts, but [Jesse] points out that a good quality air assist isn’t just about how hard the air blows, it’s also about how smoothly it does so. A turbulent air assist can make scorch marks worse, not better.

3D-printed nozzle to promote laminar air flow on the left, stock nozzle on the right.

As an experiment to improve the quality of the air flowing out the laser nozzle, [Jesse] researched ways to avoid turbulence by creating laminar flow. Laminar flow is the quality of a liquid having layers flowing past one another with little or no mixing. One way to do this is to force liquid through individual, parallel channels as it progresses towards a sharply-defined exit nozzle. While [Jesse] found no reference designs of laminar flow nozzles for air assists, there were definitely resources on making laminar flow nozzles for water. It turns out that interest in such a nozzle exists mainly as a means of modifying Lonnie Johnson’s brilliant invention, the Super Soaker.

Working from such a design, [Jesse] created a custom nozzle to help promote laminar flow. Sadly, a laser cutter head carries design constraints that make some compromises unavoidable; one is limited space, and another is the need to keep the laser’s path unobstructed. Still, after 3D printing it in rigid heat-resistant resin, [Jesse] found a dramatic improvement in the feel of the air exiting the nozzle. Some test cuts confirmed a difference in performance, which results in a noticeably cleaner kerf without scorching around the edges.

One of the things [Nervous System] does is make their own custom puzzles, so any improvement to laser cutting helps reliability and quality. When production is involved, just about everything matters; a lesson [Nervous System] shared when they discussed making the best plywood for creating their puzzles.

Making A Gorgeously-Twisty Sculpture, Using Only Flat Pieces

May 11, 2020 by Donald Papp 2 Comments

Closeup of unique pieces that make up the final scuplture.

The sculpture shown here is called Puzzle Cell Complex and was created by [Nervous System] as an art piece intended to be collaboratively constructed by conference attendees. The sculpture consists of sixty-nine unique flat panel pieces, each made from wood, which are then connected together without the need for tools by using plastic rivets. Everything fits into a suitcase and assembly documentation is a single page of simple instructions. The result is the wonderfully-curved gyroid pattern you see here.

The sculpture has numerous layers of design, not the least of which was determining how to make such an organically-curved shape using only flat panels. The five-foot assembled sculpture has a compelling shape, which results from the sixty-nine individual panels and how they fit together. These individual panel shapes have each been designed using a technique called variational surface cutting to minimize distortion, resulting in their meandering, puzzle-piece-like outlines. Each panel also has its own unique pattern of cutouts within itself, which makes the panels lighter and easier to bend without sacrificing strength. The short video embedded below shows the finished sculpture in all its glory.

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This Dibbling Plate Will Grow Your Love For Sowing

October 7, 2019 by Kristina Panos 13 Comments

One of the best things about 3D printers and laser cutters is their ability to produce specialized tools that steal time back from tedious processes. Seed sowing is a great example of this. Even if you only want to sow one tray with two dozen or so seeds, you still have to fill the tray with soil, level it off, compress it evenly, and poke all the holes. When seed sowing is the kernel of your bread and butter, doing all of that manually will eat up a lot of time.

There are machines out there to do dibbling on a large scale, but [Michael Ratcliffe] has been dabbling in dibbling plates for the smaller-scale farm. He’s created an all-in-one tool that does everything but dump the soil in the tray. Once you’ve done that, you can use edge to level off the excess soil, compress it with the back side, and then flip to the bed-of-nails side to make all the holes at once. It comes apart easily, so anyone can replace broken or dulled dibblers.

[Michael] is selling these fairly cheaply, but you can find all the files and build instructions out there in the Thingiverse. We planted the demo video after the break.

More into micro-greens? 3D printing can feed that fixation, too.

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Plastics: Acrylic

January 16, 2019 by Dan Maloney 32 Comments

If anything ends up on the beds of hobbyist-grade laser cutters more often than birch plywood, it’s probably sheets of acrylic. There’s something strangely satisfying about watching a laser beam trace over a sheet of the crystal-clear stuff, vaporizing a hairs-breadth line while it goes, and (hopefully) leaving a flame-polished cut in its wake.

Acrylic, more properly known as poly(methyl methacrylate) or PMMA, is a wonder material that helped win a war before being developed for peacetime use. It has some interesting chemistry and properties that position it well for use in the home shop as everything from simple enclosures to laser-cut parts like gears and sprockets.

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