This 3D Printed LED Softbox Really Shines

February 10, 2019 by Tom Nardi 8 Comments

Generally speaking, objects made on desktop 3D printers are pretty small. This is of course no surprise, as filament based printers are fairly slow and most don’t have very large beds to begin with. Most people don’t want to wait days for their project to complete, so they use 3D printed parts where it makes sense and supplement them with more traditional components such as aluminum extrusion wherever possible. But not always…

This 3D printed photography softbox created by [Nicholas Sherlock] doesn’t take the easy way out for anything. With the exception of the LEDs and the electronics to drive them, everything in the design has been printed on his Prusa i3. It wasn’t the easiest or fastest way to do it, but it’s hard to argue with the end result. Perhaps even more impressive than the final product is what it took to get there: he actually had to develop a completely new style of part infill he’s calling “Scattered Rectilinear” to pull it off.

Overall the design of the light itself isn’t that complex, ultimately it’s just a box with some LEDs mounted at the back and a pretty simple circuit to control their intensity. The critics will say he could have just used a cardboard box, or maybe wood if he wanted something a little bit stronger. But the point of this project was never the box itself, or the LEDs inside it. It’s all about the diffuser.

[Nicholas] forked Prusa’s version of Slic3r to add in his “Scattered Rectilinear” infill pattern, which is specifically designed to avoid the standard “ribs” inside of a 3D printed object. This is accomplished with randomized straight infill passes, rather than the traditionally overlapped ones. The inside of the print looks very reminiscent of fiberglass mat, which is perhaps the best way to conceptualize its construction. In terms of the final part strength, this infill is abysmal. But on the plus side, the light from the LEDs passing through it emerges with a soft pleasing look that completely obscures the individual points of light.

Anyone with a big enough 3D printer can run off their own copy of his light, as [Nicholas] has released not only his forked version of Slic3r but all of the STL files for the individual components. He’s also put together an exceptionally well documented Thingiverse page that has instructions and detailed build photos, something that’s unfortunately very rare for that platform.

If you’re in the market for a DIY softbox and don’t have a 3D printer handy, fear not. We’ve covered a few that you can build with more traditional methods, as well as several tips and tricks which you can use to get the most out of your photos and videos.

Kinematic Mount For 3D Printer Bed Shows Practical Design

February 9, 2019 by Donald Papp 8 Comments

Aluminum bed with new kinematic mount and base on printer *Son of Megamax*, at the Milwaukee Makerspace

[Mark Rehorst] has been busy designing and building 3D printers, and Son of Megamax — one of his earlier builds — needed a bed heater replacement. He took the opportunity to add a Kelvin-type kinematic mount as well. The kinematic mount and base efficiently constrain the bed in a controlled way while allowing for thermal expansion, providing a stable platform that also allows for removal and repeatable re-positioning.

After a short discussion regarding the heater replacement, [Mark] explains the design and manufacture of his kinematic mount. Of particular note are the practical considerations of the design; [Mark] aimed to use square aluminum tubing as much as possible, with machining requirements that were easily done with the equipment he had available. Time is a resource after all, and design decisions that help one get something working quickly have a value all their own.

If you’re still a bit foggy on kinematic mounts and how they work, you’re not alone. Check out our coverage of this 3D-printed kinematic camera mount which should make the concept a bit clearer.

Play Chess Like Harry Potter

February 9, 2019 by Al Williams 10 Comments

If you are a Harry Potter fan, you might remember that one of the movies showed an Isle of Lewis chess set whose pieces moved in response to a player’s voice commands. This feat has been oft replicated by hackers and [amoyag00] has a version that brings together a Raspberry Pi, Arduino, Android, and the Stockfish chess engine in case you want to play by yourself. You can see a video of the game, below.

Interestingly, the system uses Marlin — the 3D printing software — to handle motion using the Arduino. We suppose moving chess pieces over a path isn’t much different than moving a print head. It is certainly a novel use of GCode.

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3D Printed Diffusers Make More Natural Light

February 9, 2019 by Richard Baguley 11 Comments

A strip of LEDs may be a simple and flexible way to add light to a project, but they don’t always look natural. There is an easy way to make them look better, though: add a diffuser. That’s what [Nate Damen] did using a 3D printer. He created a diffuser using PETG giving a standard string of LEDs a softer and more natural look that makes them look more like older light sources such as fluorescent strips or EL wire, but with the flexible colors of LEDs. The PETG material he used has a naturally somewhat cloudy look, so it acts as a diffuser without needing any extra treatment.

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A Crash Course In 3D Printed Venturi Pumps

February 8, 2019 by Tom Nardi 15 Comments

Venturi pumps, commonly referred to as aspirators, are a fantastic way of moving around things which you might not want spinning around inside of a pump, and one of the easiest ways to create a vacuum. According to his research, [Tuval Ben Dosa] believed such a device would be a good way to move corrosive gasses which would normally eat up a blower fan; all he had to do was figure out how to 3D print one to his specifications.

Put simply: if you take a “T” shaped pipe and pass a fluid (such as air or water) through the straight section, a vacuum will be created on the shorter side due to the Venturi effect. As long as you don’t mind the substance you wish to pump getting mixed into your working fluid, it’s a simple way to bring something “along for the ride” as the fluid makes its way through the pipe.

[Tuval] needed a way to remove the chlorine gasses produced by his PCB etching station, and an aspirator seemed like the perfect solution. He just needed to pump clean air through a Venturi, which would suck up the chlorine gas on the way through, and ultimately carry it outside. But he soon found that while a pump based on the Venturi effect is simple conceptually, getting it to work in the real world is a bit trickier. Especially when you’re dealing with something like 3D printing, which brings in its own unique challenges.

He tried modeling a few designs he found online in 3D and printing them out, but none of them worked as expected. The most common problem was simply that no vacuum was being generated, air was freely moving out of both sides. While [Tuval] doesn’t claim to have any great knowledge of fluid dynamics, he reasoned that the issue was due to the fact that most Venturi pumps seem designed to move water rather than air. So he designed a new version of the pump which had a more pronounced nozzle on the inlet surrounded by a cavity in which the gases could mix.

His modified design worked, and now anyone with a 3D printer can run off their own Venturi device for quickly and easily giving potentially harmful fumes or gases the boot. If this is one of those things you’d feel more comfortable buying than building, don’t worry, we’ve previously covered using a low-cost aspirator as a vacuum source in the home lab.

Purge Buckets To Help With Multimaterial Printing

February 7, 2019 by Lewin Day 7 Comments

3D printing is cool, but most basic fused deposition printers just print in a single color. This means that if you want a prettier, more vibrant print, you need to paint or perform some other kind of finishing process. Multimaterial printers that can switch filaments on the fly exist, but they often have an issue with waste. [3DMN] decided to attempt building a purge bucket as a solution.

[3DMN] was previously familiar with using a purge block when running multimaterial prints. A basic block model is printed along side the actual desired part. The block is printed so that it is at the same layer height as the desired part, so the nozzle can purge cleanly without stringing plastic all over the print bed.

Tired of the waste, [3DMN] designed a purge bucket which moves with the Z-axis of his Geeetech A20M printer. The bucket attaches to the Z-axis with lock nuts and is always at the same height relative to the nozzle, regardless of the stage of printing. When a material change is required, the nozzle moves to the bucket, purges the filament, and then moves back to the print. The bucket features a 3mm silicone wiper to help ensure there is no material left clinging to the nozzle after the purge is complete, and aluminium tape which helps prevent the purged filament sticking to the walls of the bucket.

[3DMN] notes there’s also a speed increase for some prints, due to no longer needing to print purge objects along with the main part. The parts are available on Thingiverse for those of you wishing to experiment with your own setup.

Multimaterial printing can have some great visual results, and it’s great to see the community providing solutions to improve the process and reduce the waste involved. We’ve also seen filament splicing, which is another unique approach to multimaterial prints. Video after the break.

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Finite Element Analysis Results In Smart Infill

February 6, 2019 by Brian Benchoff 16 Comments

If you would like to make a 3D print stronger, just add more material. Increase the density of the infill, or add more perimeters. The problem you’ll encounter though is that you don’t need to add more plastic everywhere, only in the weak areas of the part that will be subjected to the most stress. Studying where parts will be the weakest is the domain of finite element analysis, and yes, you can do it in Fusion 360. With the right techniques, you can make a stronger part on your 3D printer, and [Stefan] is here to show you how to do it.

The inspiration for this build comes from [Adrian Bowyer]’s blog, where he talks about adding ‘fibers’ to the interior of 3D printed objects to increase strength. These ‘fibers’ aren’t really fibers at all, but long, thin, cylindrical voids. The theory of this is that the slicer will interpret this as a hole and place perimeters around these voids, effectively increasing the density of the infill in a local area in the print. Combine this with finite element analysis, and you get a part that is stronger where it needs to be, and doesn’t waste plastic.

However, there is an easier way. Fusion 360 and ANSYS Finite Element Simulation are both free-ish tools that allow for some amount of finite element analysis on an imported 3D object. This can be used to find the weakest part of any 3D print, and it can this can be exported as a 3D mesh. Slic3r has a modifier mesh function, and combining this finite element analysis mesh (printed at 100% infill) with the original part (printed at 10% or so infill) results in something that’s strong where it needs to be, doesn’t waste plastic, and is much easier to set up than [Adrian Bowyer]’s ‘fiber’ technique.

After printing a few 3D printed hooks with varying degrees and techniques of infill, [Stefan] found the baseline of 2 perimeters failed in a test hook at about 50kg load. The Smart Infill hook failed at about 100kg. Not bad, and the fancy-pants hook only weighs about 30% more.

You can check out a video of the entire toolchain and testing below. Thanks [Keith] for sending this one in.

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