Holograms: The Future Of Speedy Nanoscale 3D Printing?

April 9, 2023 by Dave Rowntree 7 Comments

3D printing by painting with light beams on a vat of liquid plastic was once the stuff of science fiction, but now is very much science-fact. More than that, it’s consumer-level technology that we’re almost at the point of being blasé about. Scientists and engineers the world over have been quietly beavering away in their labs on the new hotness, nanoscale 3D printing with varying success. Recently IEESpectrum reports some promising work using holographic imaging to generate nanoscale structures at record speed.

Current stereolithography printers make use of UV laser scanned over the bottom of a vat of UV-sensitive liquid photopolymer resin, which is chemically tweaked to make it sensitive to the UV frequency photons. This is all fine, but as we know, this method is slow and can be of limited resolution, and has been largely superseded by LCD technology. Recent research has focussed on two-photon lithography, which uses a resin that is largely transparent to the wavelength of light concerned, but critically, can be polymerized with enough energy density (i.e. the method requires multiple photons to be simultaneously absorbed.) This is achieved by using pulsed-mode lasers to focus to a very tight point, giving the required huge energy density. This tight focus, plus the ability to pass the beam through the vat of liquid allows much tighter image resolution. But it is slow, painfully slow.

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Fast Scanning Bed Leveling

April 6, 2023 by Al Williams 29 Comments

The bane of 3D printing is what people commonly call bed leveling. The name is a bit of a misnomer since you aren’t actually getting the bed level but making the bed and the print head parallel. Many modern printers probe the bed at different points using their own nozzle, a contact probe, or a non-contact probe and develop a model of where the bed is at various points. It then moves the head up and down to maintain a constant distance between the head and the bed, so you don’t have to fix any irregularities. [YGK3D] shows off the Beacon surface scanner, which is technically a non-contact probe, to do this, but it is very different from the normal inductive or capacitive probes, as you can see in the video below. Unfortunately, we didn’t get to see it print because [YGK3D] mounted it too low to get the nozzle down on the bed. However, it did scan the bed, and you can learn a lot about how the device works in the video. If you want to see one actually printing, watch the second, very purple video from [Dre Duvenage].

Generally, the issues with probes are making them repeatable, able to sense the bed, and the speed of probing all the points on the bed. If your bed is relatively flat, you might get away with probing only 3 points so you can understand how the bed is tilted. That won’t help you if your bed has bumps and valleys or even just twists in it. So most people will probe a grid of points.

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Magic 8 Ball Provides Tech Support

March 28, 2023 by Bryan Cockfield 15 Comments

ChatGPT might be making the news these days for being able to answer basically any question it’s asked, those of us who are a little older remember a much simpler technology that did about the same thing. The humble “Magic 8 Ball” could take nearly the same inputs, provided they were parsed in simple yes/no form, and provide marginal help similar to the AI tools of today. For a toy with no battery or screen, this was quite an accomplishment. But the small toy couldn’t give specific technical support help, so [kodi] made one that can.

The new 8 Ball foregoes the central fluid-filled chamber for an STM32 Blue Pill board with a few lithium batteries to power it. The original plastic shell was split in two with a hacksaw and fitted with a 3D printed ring which allows the two halves to be reconnected and separated again when it needs to charge. It uses a circular OLED to display the various messages of tech support, which are displayed when an accelerometer detects that the toy has been shaken.

Granted, most of the messages are about as helpful to solving a tech support issue as the original magic 8 Ball’s would have been, but we appreciate the ingenuity and carefree nature of a project like this. It also did an excellent job at operating in a low-power state as well, to avoid needing to charge it often. There have been a few other digital conversions of these analog fortune tellers as well, like this one which adds GIFs to each of the original answers.

A Comprehensive Look At FDM Supports

March 27, 2023 by Al Williams 13 Comments

When we first started 3D printing, we used ABS and early slicers. Using supports was undesirable because the support structures were not good, and ABS sticks to itself like crazy. Thankfully today’s slicers are much better, and often we can use supports that easily detach. [Teaching Tech] shows how modern slicers create supports and how to make it even better than using the default settings.

The video covers many popular slicers and their derivatives. If you’ve done a lot with supports, you might not find too much of this information surprising, but if you haven’t printed with supports lately or tried things like tree supports, you might find a few things that will up your 3D printing game.

One thing we really like is that the video does show different slicers, so regardless of what slicer you like to use, you’ll probably find exactly what different settings are called. Of course, because slicers let you examine what they produce layer-by-layer, you can do like the video and examine the results without printing. [Michael] does do some prints with various parameters, though, and you can see how hard or easy the support removal is depending on some settings. The other option is to add support to your designs, as needed manually, or — even better — don’t design things that need support.

This video reminded us of a recent technique we covered that added a custom support tack to help the slicer’s automatic support work better. If you want a longer read on supports that also covers dissolvable support, we’ve seen that, too.

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Advanced 3D Printing Tips

March 17, 2023 by Al Williams 23 Comments

One of the best things about hanging around with other hackers is you hear about the little tricks they use for things like 3D printing. But with the Internet, you can overhear tips from people you’ll probably never meet, like [3D Printer Academy]. His recent video has a little bit of a click-bait title (“10 Secret 3D Printing Tricks…“) but when we watched it, we did see several cool ideas. Of course, you probably know at least some of the ten tips, but it is still interesting to see what he’s been up to, which you can do in the video below.

At one point he mentions 11 tips, but the title has 10 and we had to stretch to get to that number since some of them have some overlap. For example, several involve making printed threads. However, he also shows some C-clips, a trick to add walls for strength, and printing spur gears. Of course, some of these, like the gears, require specific tools, but many of them are agnostic.

Some of the tips are about selecting a particular infill pattern, which you’d think would be pretty obvious, but then again, your idea of what’s novel and what’s old hat might be different than ours. The explanation of how a print-in-place hinge works is pretty clear (even if it isn’t really a live hinge) and also applies to making chains to transfer power. We also thought the threaded containers were clever.

So if you can overlook the title and you don’t mind seeing a few tips you probably already know, you can probably take something away from the video. What’s your favorite “expert” trick? Let us know in the comments.

A lot of what we print tends to be enclosures and there are some good tips for those floating around. Of course, the value of tips vary based on your experience level. But if you are just starting out, you should check out [Bald Engineer]’s video of things he wished someone had told him when he started 3D printing.

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FDM Printing With Resin Update

March 4, 2023 by Al Williams 15 Comments

[Proper Printing] is at it again. He’s trying to perfect his hybrid printer that works like an FDM printer but uses UV-curable resin gel instead of filament. You can see the latest update video below. If you missed our take on his early attempts, you might want to catch up with those earlier videos first.

The latest update brings a new nozzle, an improved light source, and changes to the formula of the resin. The nozzle and light source improvements hinge on conical lenses that convert the laser beams from a spot to a ring. The initial nozzles looked like the business end of a syringe, but this wasn’t very stable. The new video shows a conventional nozzle which also had some issues. This resulted in a custom-made nozzle that solved all the issues with the conventional nozzle and the syringe tips.

The resin formula is particularly crucial. The second attempt used resin with glass beads to give thickness. That wasn’t without problems, though, so it was switched this time with fused silica, as suggested by some comments on a previous video. They also used aggressive mixing and air removal. The consistency of the previous resins was that of a paste, but according to the video, the new mixture is more like a gel.

At some point, things started going badly. There were several equipment failures. Exasperated, he was ready to give up and was editing the video when he had an epiphany. We’re glad he didn’t give up because the new results are pretty impressive.

These printers remind us of some strange laser CNC. It also reminds us a little of people curing resin outside of the normal print process.

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Arc Overhangs In PrusaSlicer Are A Simple Script Away

February 28, 2023 by Donald Papp 21 Comments

Interested in the new hotness of printing previously-impossible overhangs? You can now integrate Arc Overhangs into PrusaSlicer and give it a shot for yourself. Arc overhangs is a method of laying filament into a pattern of blossoming concentric rings instead of stringing filament bridges over empty space (or over supports).

These arcs are remarkably stable, and result in the ability to print overhangs that need to be seen to be believed. We covered this clever technique in the past and there are now two ways for the curious hacker to try it out with a minimum of hassle: either run the Python script on a G-code file via the command line, or integrate the functionality into PrusaSlicer directly by adding it as an automatic post-processing script. The project’s GitHub repository has directions for both methods.

Here’s how it works: the script looks for layers with a “bridge infill” tag (which PrusaSlicer helpfully creates) and replaces that G-code with that for arc overhangs. It is still a work in progress, so keep a few things in mind for best results. Arc overhangs generally work best when the extruded plastic cools as fast as possible. So it is recommended to extrude at the lowest reliable temperature, slowly, and with maximum cooling. It’s not fast, but it’s said to be faster than wrestling with supports and their removal.

A few things could use improvement. Currently the biggest issue is warping of the arc overhangs when new layers get printed on top of them. Do you have a solution or suggestion? Don’t keep it to yourself; discuss in the comments, or consider getting involved in the project.