Stop Ironing 3D Prints

If you want smooth top surfaces on your 3D printed parts, a common technique is to turn on ironing in your slicer. This causes the head to drag through the top of the part, emitting a small amount of plastic to smooth the surface. [Make Wonderful Things] asserts that you don’t need to do this time-consuming step. Instead, he proposes using statistical analysis to identify the optimal settings to place the top layer correctly the first time, as shown in the video below.

The parameters he thinks make a difference are line width, flow ratio, and print speed. Picking reasonable step sizes suggested that there were 19,200 combinations of settings to test. Obviously, that’s too many, so he picked up techniques from famous mathematician [George E. P. Box] and also used Bayesian analysis to reduce the amount of printing required to converge on the perfect settings.

Did it work? Judging from the video, it appears to have done so. The best test pieces looked as good as the one that used traditional ironing. Compared to ironing, the non-ironed parts saved about 34% of print time. Not bad.

Of course, there are variations on traditional ironing, so your results may vary.

Continue reading “Stop Ironing 3D Prints”

Sub-Second Volumetric 3D Printing

One of the more promising 3D printing technologies that hasn’t quite yet had its spotlight is volumetric 3D printing. Researchers from the Department of Automation, Tsinghua University, have developed a new method that uses a high-speed periscope instead of rotating the printing volume — resulting in print times of less than one second.

Normal volumetric printing uses a rotating volume of photosensitive resin to print nearly any geometry desired. However, this method presents issues when printing at high speeds. If you rapidly rotate a liquid, it won’t exactly stay still. So why not rotate the projector itself? This change also allows the use of less viscous resins, which is particularly useful if you want to pump fluid around.

Why would you want to pump around liquid? Scalability of course! Printing in seconds while pumping the results into a collection vessel would allow for mass production more flexible than traditional ejection methods. The researchers manage to keep quality high with some fancy algorithmic correction, which allows for accuracy on the scale of μm.

While this technology still doesn’t find a common space among average hobbyists, this may soon change…especially with these mass manufacturing capabilities. For similar volumetric printing capabilities, check out xolography.

There’s Always Room For 3D Printed Batteries

There are many applications where you have limits on how much you can cram into a particular space. There are also many applications where you need as much battery as you can get. At the intersection of those applications, you may soon be able to 3D print custom batteries to fit into oddly shaped spaces that might otherwise go to waste.

Commercial batteries are typically cylindrical or rectangular. In theory, you could build tooling to make batteries of any size or shape you want, but it’s an expensive process in small quantities. [Lawrence Ulrich] on Spectrum talks about a new process, developed by [Gabe Elias], that can print anodes, cathodes, separators, and casings for custom battery shapes with no costly tooling.

As an example, consider an unmanned aerial vehicle crammed with avionics. You could put off-the-shelf batteries in the wings, but you’ll end up wasting a lot of space. A custom battery could fill the wing’s interior completely. The post also mentions batteries shaped like the earpieces of a pair of smart glasses.

A prototype showed that in the space of 48 cylindrical cells, the new process could deliver a printed battery that uses 35% more of the available volume and a 50% boost in energy density.

Could you do this yourself? Maybe, but it won’t be trivial. The current process requires a liquid electrolyte and the ability to produce thin layers of exotic materials. What oddly-shaped battery would you like to see? Us? We’d like to have a battery for a laptop that was spread uniformly so there wasn’t a heavy side that has the battery.

Thermoforming: Shaping Curvy Grilles With No Supports

Making sure the heatgun is on 'low' and gloves are on while pushing on the mold. (Credit: Zion Brock)
Making sure the heatgun is on ‘low’ and gloves are on while pushing on the mold. (Credit: Zion Brock)

Although hobbyists these days most often seem to use thermoplastics as a print-and-done material in FDM printers, there’s absolutely nothing stopping you from taking things further with thermoforming. Much like forming acrylic using a hot wire or hot air, thermoplastics like PLA can be further tweaked with a similar method. This can be much less complex than 3D printing the design with supports, as demonstrated by [Zion Brock].

For this classically styled radio project the front grille was previously 3D printed with the curved shape, but to avoid an ugly edge it had to be printed with most of the grille off the print bed, requiring countless supports and hours of printing time. To get around this, [Zion] opted to print the grille flat and then thermoform its curved shape. Of course, due to the unusual shape of the grille, this required a bit more effort than e.g. a spherical form.

This is similar to what is used with sheet metal to get detailed shaped, also requiring a mold and a way to stretch the flat shape over the mold. With the flat form designed to have all the material in the right places, it was able to be printed in less than an hour in PLA and then formed with a heatgun aimed at the part while the two-section mold is slid together to create the final form.

You can find the design files and full instructions on the website for the radio project.

Continue reading “Thermoforming: Shaping Curvy Grilles With No Supports”

Art of 3D printer in the middle of printing a Hackaday Jolly Wrencher logo

Does Carbon Fiber PLA Make Sense?

Carbon fiber (CF) has attained somewhat of a near-mystical appeal in consumer marketing, with it being praised for being stronger than steel while simultaneously being extremely lightweight. This mostly refers to weaved fibers combined with resin into a composite material that is used for everything from car bodies to bike frames. This CF look is so sexy that the typical carbon-fiber composite weave pattern and coloring have been added to products as a purely cosmetic accent.

More recently, chopped carbon fiber (CCF) has been added to the thermoplastics we extrude from our 3D printers. Despite lacking clear evidence of this providing material improvements, the same kind of mysticism persists here as well. Even as evidence emerges of poor integration of these chopped fibers into the thermoplastic matrix, the marketing claims continue unabated.

As with most things, there’s a right way and a wrong way to do it. A recent paper by Sameh Dabees et al. in Composites for example covered the CF surface modifications required for thermoplastic integration with CF.

Continue reading “Does Carbon Fiber PLA Make Sense?”

Touchless Support Leaves No Mark

[Clough42] created a 3D print for a lathe tool and designed in some support to hold the piece on the bed while printing. It worked, but removing the support left unsightly blemishes on the part. A commenter mentioned that the support doesn’t have to exactly touch the part to support it. You can see the results of trying that method in the video below.

In this case [Cloug42] uses Fusion, but the idea would be the same regardless of how you design your parts. Originally, the support piece was built as a single piece along with the target object. However, he changed it to make the object separate from the support structure. That’s only the first step, though. If you import both pieces and print, the result will be the same.

Instead, he split the part into the original two objects that touch but don’t blend together. The result looks good.

We couldn’t help but notice that we do this by mistake when we use alternate materials for support (for example, PETG mixed with PLA or PLA with COPE). Turns out, maybe you don’t have to switch filament to get good results.

Continue reading “Touchless Support Leaves No Mark”

Multi-material Parts The Easy Way

You have a part that needs different colors or different material properties — with a multi-color 3D printer, no problem. You can also laboriously switch filaments on a single-color printer. But [anonymous kiwi] points out a different way, which is surprisingly obvious once you think about it. You simply add a previously made part to another one.

If you’ve ever experimented with adding a nut or a magnet into a print in the middle, the idea is exactly the same: you print one piece and then print a second piece, pausing in the middle to insert the completed first piece. The video example shows TPU robot wheels with PLA hubs. Of course, the same idea could apply to using different colors or even multiple materials or parts. You could imagine a hub with a steel nut embedded in it, then further being embedded in a TPU wheel, for example.

With multi-material printers becoming more commonplace, this technique might seem antiquated. But even if you have one of such a printer, this technique could save time and reduce waste. Not every part would work out this cleanly, but it is something to remember for the times when it does.

Continue reading “Multi-material Parts The Easy Way”