3D-Printing A Full-Sized Kayak In Under A Day

August 12, 2025 by Lewin Day 25 Comments

If you want to get active out on the water, you could buy a new kayak, or hunt one down on Craigslist, Or, you could follow [Ivan Miranda]’s example, and print one out instead.

[Ivan] is uniquely well positioned to pursue a build like this. That’s because he has a massive 3D printer which uses a treadmill as a bed. It’s perfect for building long, thin things, and a kayak fits the bill perfectly. [Ivan] has actually printed a kayak before, but it took an excruciating 7 days to finish. This time, he wanted to go faster. He made some extruder tweaks that would allow his treadmill printer to go much faster, and improved the design to use as much of the belt width as possible. With the new setup capable of extruding over 800 grams of plastic per hour, [Ivan] then found a whole bunch of new issues thanks to the amount of heat involved. He steps through the issues one at a time until he has a setup capable of extruding an entire kayak in less than 24 hours.

This isn’t just a dive into 3D printer tech, though. It’s also about watercraft! [Ivan] finishes the print with a sander and a 3D pen to clean up some imperfections. The body is also filled with foam in key areas, and coated with epoxy to make it watertight. It’s not the easiest craft to handle, and probably isn’t what you’d choose for ocean use. It’s too narrow, and wounds [Ivan] when he tries to get in. It might be a floating and functional kayak, just barely, for a smaller individual, but [Ivan] suggests he’ll need to make changes if he were to actually use this thing properly.

Overall, it’s a project that shows you can 3D print big things quite quickly with the right printer, and that maritime engineering principles are key for producing viable watercraft. Video after the break.

Continue reading “3D-Printing A Full-Sized Kayak In Under A Day” →

2025 One Hertz Challenge: Abstract Aircraft Sculpture Based On Lighting Regulations

August 12, 2025 by Lewin Day 9 Comments

The 2025 One Hertz Challenge is really heating up with all kinds of projects that do something once every second. [The Baiko] has given us a rather abstract entry that looks like a plane…if you squint at it under the right conditions.

It’s actually quite an amusing abstract build. If you’ve ever seen planes flying in the night sky, you’ve probably noticed they all have similar lights. Navigation lights, or position lights as they are known, consist of a red light on the left side and a green light on the right side. [The Baiko] assembled two such LEDs on a small sliver of glass along with an ATtiny85 microcontroller.

Powered by a coin cell, they effectively create a abstract representation of a plane in the night sky, paired with a flashing strobe that meets the requirements of the contest. [The Baiko] isn’t exactly sure of the total power draw, but notes it must be low given the circuit has run for weeks on a 30 mAh coin cell.

It’s an amusing piece of PCB art, though from at least one angle, it does appear the red LED might be on the wrong side to meet FAA regulations. Speculate on that in the comments.

In any case, we’ve had a few flashers submitted to the competition thus far, and you’ve got until August 19 to get your own entry in!

Continuous-Path 3D Printed Case Is Clearly Superior

August 12, 2025 by Lewin Day 9 Comments

[porchlogic] had a problem. The desire was to print a crystal-like case for an ESP32 project, reminiscent of so many glorious game consoles and other transparent hardware of the 1990s. However, with 3D printing the only realistic option on offer, it seemed difficult to achieve a nice visual result. The solution? Custom G-code to produce as nice a print as possible, by having the hot end trace a single continuous path.

The first job was to pick a filament. Transparent PLA didn’t look great, and was easily dented—something [porchlogic] didn’t like given the device was intended to be pocketable. PETG promised better results, but stringing was common and tended to reduce the visual appeal. The solution to avoid stringing would be to stop the hot end lifting away from the print and moving to different areas of the part. Thus, [porchlogic] had to find a way to make the hot end move in a single continuous path—something that isn’t exactly a regular feature of common 3D printing slicer utilities.

The enclosure itself was designed from the ground up to enable this method of printing. Rhino and Grasshopper were used to create the enclosure and generate the custom G-code for an all-continuous print. Or, almost—there is a single hop across the USB port opening, which creates a small blob of plastic that is easy to remove once the print is done, along with strings coming off the start and end points of the print.

Designing an enclosure in this way isn’t easy, per se, but it did net [porchLogic] the results desired. We’ve seen some other neat hacks in this vein before, too, like using innovative non-planar infill techniques to improve the strength of prints.

Continue reading “Continuous-Path 3D Printed Case Is Clearly Superior” →

Physical Aimbot Shoots For Success In Valorant

August 11, 2025 by Lewin Day 17 Comments

Modern competitive games have a great deal of anti-cheat software working to make sure you can’t hack the games to get a competitive advantage. [Kamal Carter] decided to work around this by building a physical aimbot for popular FPS Valorant.

The concept is straightforward enough. [Kamal] decided to hardmount an optical mouse to a frame, while moving a mousepad around beneath it with an off-the-shelf Cartesian CNC platform, but modified to be driven by DC motors for quick response. This gave him direct control over the cursor position which is largely undistinguishable from a human being moving the mouse. Clicking the mouse is achieved with a relay. As for detecting enemies and aiming at them, [Kamal] used an object detection system called YOLO. He manually trained the classifier to detect typical Valorant enemies and determine their position on the screen. The motors are then driven to guide the aim point towards the enemy, and the fire command is then given.

The system has some limitations—it’s really only capable of completing the shooting range challenges in Valorant. The vision model isn’t trained on the full range of player characters in Valorant, and it would prove difficult to use such a system in a competitive match. Still, it’s a neat way to demonstrate how games can be roboticized and beaten outside of just the software realm. Video after the break. Continue reading “Physical Aimbot Shoots For Success In Valorant” →

Building A Trash Can Reverb

August 11, 2025 by Lewin Day 6 Comments

These days, if you want a reverb effect, you just dial up whatever software plugin most appeals to you and turn the dials to taste. However, [Something Physical] specialises in… physical things… and thus built a reverb the old fashioned way. Using a trashcan, of course.

The concept is simple enough—the method of operation is exactly the same as any old plate reverb. Audio is played through a speaker connected to the plate (or trashcan), causing it to vibrate. The sound is then picked up at another point on the plate (or trashcan) with some kind of microphonic pickups, amplified, and there you have your reverb signal.

Given it’s built around a piece of street furniture, [Something Physical] has dubbed this the Street-Verb. It uses a class D amp to drive a speaker with a bolt stuck to it. The bolt is then put in contact with the trashcan itself to transfer the vibration. A pair of piezo elements are used as the pickups, run through a preamps built with a humble BC109C transistor. Since there are two pickups, the Street-Verb is effectively a stereo reverb unit, though the input is only mono. [Something Physical] set up the speaker driver and pickups to be easily movable, and was able to test the device with all kinds of street furniture, like gates and street signs, but the trashcan ‘verb setup is by far the most compelling.

We’ve featured other plate reverb builds before, too, albeit less garbage-themed. Video after the break.

Continue reading “Building A Trash Can Reverb” →

The Trials Of Trying To Build An Automatic Filament Changer

August 11, 2025 by Lewin Day 17 Comments

Running out of filament mid-print is a surefire way to ruin your parts and waste a lot of time. [LayerLab] was sick of having this problem, and so sought to find a proper solution. Unfortunately, between off-the-shelf solutions and homebrew attempts, he was unable to solve the problem to his satisfaction.

[LayerLab] had a simple desire. He wanted his printer to swap to a second spool of filament when the first one runs out, without ruining or otherwise marring the print. It sounds simple, but the reality is more complicated. As an Australian, he couldn’t access anything from InfinityFlow, so he first attempted to use the “auto refill” features included on the Bambu Labs AMS 2. However, it would routinely make filament changes in outside wall areas of a print, leaving unsightly marks and producing poorer quality parts.

His next effort was to use the Wisepro Auto Refill Filament Buffer. It’s a feeder device that takes filament from two spools, and starts feeding the backup spool in to your printer when the primary spool runs out. Unfortunately, [LayerLab] had a cavalcade of issues with the device. It would routinely feed from the secondary spool when there was still primary filament available, jamming the device, and it didn’t come with a proper mounting solution to work with consumer printers. It also had bearings popping out the top of the housing. Attempts to rework the device into a larger twin-spool rig helped somewhat, but ultimately the unreliability of the Wisepro when changing from one spool to another meant it wasn’t fit for purpose. Its feeder motors were also to trigger the filament snag cutters that [LayerLab] had included in his design.

Ultimately, the problem remains unsolved for [LayerLab]. They learned a lot along the way, mostly about what not to do, but they’re still hunting for a viable automatic filament changer solution that suits their needs. Filament sensors help, but can only do so much. If you reckon you know the answer, or a good way forward, share your thoughts in the comments. Video after the break.

Continue reading “The Trials Of Trying To Build An Automatic Filament Changer” →

2025 One Hertz Challenge: Using Industrial Relays To Make A Flasher

August 10, 2025 by Lewin Day 8 Comments

These days, if you want to flash some LEDs, you’d probably grab a microcontroller. Maybe you’d go a little more old-school, and grab a 555. However, [Jacob] is even more hardcore than that, as evidenced by this chunky electromechanical flasher build.

[Jacob] goes into great detail on his ancillary write-up, describing how the simple building blocks used by industrial control engineers can be used to make a flasher circuit that cycles once per second. Basically, two relays are paired with two 0.5-second delay timers. The two relays tag each other on and off on delay as their timers start and expire, with the lamp turned on and off in turn.

We’ve had lots of other great entries to our One Hertz Challenge, too — from clocks to not-clocks. There’s still time to get an entry in — the deadline for submission is Tuesday, August 19 at 9:00AM Pacific time. Good luck out there!