PreFlight Slicer Brings Added Part Strength Feature, And Many More

May 15, 2026 by Donald Papp 38 Comments

Interested in taking some wild new 3D printing features for a test drive? preFlight is a free and open source slicer that brings a host of processing improvements as well as fascinating new features and interesting twists on old ones. There are almost too many to list, so here are a few that caught our eye.

Cross-sectional view of *Interlocking Perimeters*, which increases Z-strength. Unlike brick layers, layer height stays constant.

Want to mix and match different support types on the same object? No problem. How about use Nip & Tuck seams to better hide where layers start and stop? You can emboss images directly onto print surfaces with a real-time preview and use smart bridging for counter-bored holes. We particularly like the ability to preview a sliced object from the side instead of just by layer. That’s not all, either.

Those features alone are pretty intriguing, but there’s one in particular that is particularly relevant to creating stronger parts. Interlocking Perimeters increases layer bonding to increase object strength. Unlike brick layers, which staggers layers vertically, interlocking perimeters plays with spacing and compression to increase bonding in the Z axis while keeping layer heights constant. This is possible thanks in part to the greater control offered by Athena, the new perimeter generator.

There are plenty more features — like a full Python runtime embedded directly into the slicing pipeline, and a host of export pathways — so check out the GitHub repository for added detail and let us know in the comments if you give it a try.

Slicer Settings For “Indestructible” Battle-Bot Worthy PLA Parts

April 25, 2026 by Tyler August 15 Comments

If you follow [Maker’s Muse] on YouTube, you know he’s as passionate about robot fights these days as he is about the tools he uses to make the robots. Luckily for us, he’s still got fame as a 3D printing YouTuber, as this has given him the platform to share his trade secrets for strong, robot-combat-worthy prints.

He fights robots in a ‘plastic ant-weight’ division, which restricts not only the weight of the robot but also the materials used. Not only must they be primarily plastic, but only certain plastics are allowed: PLA is in, but engineering filaments, Nylon, and TPU are out. Since necessity is the mother of invention, this has led to strong evolutionary pressure to figure out how to print the most impact-resilient PLA parts for armor and spinners.

He’s using the latest OrcaSlicer and shares the profile as a pay-what-you-want 3MF file. It’s all about solidity: a solid part with solidly fused walls and solidly linked layers. It makes sense: if you’re going to be hammering on or with these parts, you don’t want any internal voids that could either collapse or pull open.

The infill density is obviously 100%, and you’ll want a concentric pattern — this makes it look like you’re just printing walls, but it allows you to use another trick. To make sure those walls don’t all align, creating a potential weakness, OrcaSlicer’s “alternate extra wall” will put one extra wall every second layer. The extra wall causes the infill pattern to stagger and lock together.

Also helping lock it together, he’s playing with extrusion widths, with the suggested rule-of-thumb being the line width on the walls be one-half that of the internal fill — and as wide as possible. In his case, with a 0.4 mm nozzle, that means 0.4 mm wide walls and 0.8 mm for the infill. OrcaSlicer 2.3.2 also lets you play with specific flow ratios, allowing you to overextrude only the internals for strength, without overextruding on the walls and potentially ruining dimensional accuracy. He also irons all top surfaces, but admits that that’s mostly about aesthetics. The iron may make those layers a little bit stronger, though, so why not?

Would brick layers make these parts even stronger? That’s very likely; [Maker’s Muse] mentions them in the video but does not use them because they’re not implemented in-slicer, and he wants something accessible to all. On the other hand, this post-processing script seems accessible enough for our crowd.

This video/profile is exclusively about fully-solid parts. When you want strong parts that aren’t fully solid, it looks like the answer is walls.

, Continue reading “Slicer Settings For “Indestructible” Battle-Bot Worthy PLA Parts” →

Removing Infill To Make 3D Printed Parts Much Stronger

October 12, 2025 by Maya Posch 21 Comments

When it comes to FDM 3D prints and making them stronger, most of the focus is on the outer walls and factors like their layer adhesion. However, paying some attention to the often-ignored insides of a model can make a lot of difference in its mechanical properties. Inspired by a string of [Tom Stanton] videos, [3DJake] had a poke at making TPU more resilient against breaking when stretched and PLA resistant to snapping when experiencing a lateral force.

Simply twisting the TPU part massively increased the load at which it snapped. Similarly, by removing the infill from the PLA part before replacing it with a hollow cylinder, the test part also became significantly more resilient. A very noticeable result of hollowing out the PLA part: the way that it breaks. A part with infill will basically shatter. But the hollowed-out version remained more intact, rather than ripping apart at the seams. The reason? The hollow cylinder shape is printed to add more walls inside the part. Plus cylinders are naturally more able to distribute loads.

All of this touches on load distribution and designing a component to cope with expected loads in the best way possible. It’s also the reason why finite element analysis is such a big part of the CAD world, and something which we may see more of in the world of consumer 3D printing as well in the future.

Continue reading “Removing Infill To Make 3D Printed Parts Much Stronger” →

3D Print Smoothing, With Lasers

October 2, 2025 by Fenix Guthrie 10 Comments

As anyone who has used an FDM printer can tell you, it’s certainly not the magical replicator it’s often made out to be. The limitations of the platform are numerous — ranging from anisotropic material characteristics to visual imperfections in the parts. In an attempt to reduce the visual artifacts in 3D prints, [TenTech] affixed a small diode laser on a 3D printer.

Getting the 1.5 watt diode laser onto the printer was a simple matter of a bracket and attaching it to the control board as a fan. Tuning the actual application of the laser proved a little more challenging. While the layer lines did get smoothed, it also discolored the pink filament making the results somewhat unusable. Darker colored filaments seem to not have this issue and a dark blue is used for the rest of the video.

The smoothing process begins at the end of a 3D print and uses non-planar printer movements to keep the laser at an ideal focusing distance. The results proved rather effective, giving a noticeably smoother and shiner quality than an unprocessed print. The smoothing works incredibly well on fine geometry which would be difficult or impossible to smooth out via traditional mechanical means. Some detail was lost with sharp corners getting rounded, but not nearly as much as [TenTech] feared.

For a final test, [TenTech] made two candle molds, one smoothed and one processed. The quality difference between the two resulting candles was minimal, with the smoothed one being perhaps even a little worse. However, a large amount of wax leaked into the 3D print infill in the unprocessed mold, with the processed mold showing no signs of leaking.

If you are looking for a bit safer of a 3D print post-processing technique, make sure to check out [Donal Papp]’s UV resin smoothing experiments!

Continue reading “3D Print Smoothing, With Lasers” →

MorPhlex: The TPU Filament That Goes Soft After You Print It

August 16, 2025 by Maya Posch 7 Comments

In FDM 3D printing cycles TPU is a bit of a special filament. Not so much because of its properties, but because it’s rather stretchy even as a filament, which makes especially printing certain hardness grades of TPU into somewhat of an nightmare. An interesting new contender here comes from a company called BIQU, who reckon that their ‘MorPhlex’ TPU solves many of those problems. Recently the [ModBot] channel on YouTube got sent a spool of the filament for testing.

The BIQU MorPhlex TPU filament being turned into squishy slippers. (Credit: ModBot, YouTube)

The ‘magic’ here is that this TPU claims to be a 90A TPU grade while on the spool, but after printing it becomes 75A, meaning a lot softer and squishier. Perhaps unsurprisingly, a big selling point on their product page is that you can print squishy shoes with it. Beyond this is claims to be compatible with ‘most FDM printers’, and the listed printing parameters are typical for TPU in terms of extruder and bed temperature.

After drying the filament as recommended for TPU in general, test prints were printed on a Bambu Lab H2D. Here BIQU recommends not using the AMS, but rather the dedicated TPU feeding channel. For the test prints some slippers were printed over the course of two days. In hindsight glue stick should have been applied to make parts removal easier.

The slippers were indeed squishy, but the real test came in the form of a Shore A hardness meter and some test cube prints. This showed an 80 – 85A for the BIQU MorPhlex test cube depending on whether to test the side or top. As the product datasheet indicates a final hardness of 75A +/- 3A, one could argue that it’s kind-of in spec, but it mostly raises questions on how parameters like temperature and extrusion speed affect the final result.

How To Design 3D-Printed Parts With Tolerance In Mind

August 4, 2025 by Maya Posch 12 Comments

One of the continuing struggles with FDM printing is making sure that parts that should fit together actually do. While adding significant tolerance between parts is an option, often you want to have a friction fit or at least a gap that you cannot drive a truck through. In a video by [Slant 3D] a number of tips and tricks to improve parts design with tolerance in mind are provided.

Starting with the fairly obvious, such as avoiding sharp corners, rounding off edges and using chamfered edges and filets for e.g. lids to make getting started easy, the video then moves into more advanced topics. Material shrinkage is a concern, which is where using thin walls instead of solid blocks of material helps, as does using an appropriate infill type. Another interesting idea is to use a compliant mechanism in the lid to get a friction fit without getting all print parameters just right.

On the opposing side to the lid – or equivalent part – you’d follow many of the same tips, with the addition of e.g. slots that allow for the part to flex somewhat. All of this helps to deal with any variability between prints, with the suggested grip fins at the end of the video being probably the most extreme.

Continue reading “How To Design 3D-Printed Parts With Tolerance In Mind” →

Destructive Testing Of ABS And Carbon Fiber Nylon Parts

July 28, 2025 by Maya Posch 10 Comments

PAHT-CF part printed at 45 degrees, with reinforcing bolt, post-failure. (Credit: Functional Print Friday, YouTube)

The good part about FDM 3D printing is that there are so many different filament types and parameters to choose from. This is also the bad part, as it can often be hard to tell what impact a change has. Fortunately we got destructive testing to provide us with some information here. Case in point [Functional Print Friday] on YouTube recently testing out a few iterations of a replacement part for a car.

The original part was in ABS, printed horizontally in a Bambu Lab FDM printer, which had a protruding element snapped off while in use. In addition to printing a replacement in carbon fiber-reinforced nylon (PAHT-CF, i.e. PA12 instead of the typical PA6), the part was now also printed at a 45° angle. To compare it with the original ABS filament in a more favorable way, the same part was reprinted at the same angle in ABS.

Another change was to add a machine screw to the stop element of the part, which turned out to make a massive difference. Whereas the original horizontal ABS print failed early and cleanly on layer lines, the angled versions put up much more of a fight, with the machine screw-reinforced stop combined with the PA12 CF filament maxing out the first meter.

The take-away here appears to be that not only angles are good, but that adding a few strategic metal screws can do wonders, even if you’re not using a more exotic filament type.

Continue reading “Destructive Testing Of ABS And Carbon Fiber Nylon Parts” →