Cookie Launcher Makes You Catch Your Own Snack

December 25, 2025 by Donald Papp 2 Comments

Holiday cookies are a joy, and to make things a bit more fun, [The Skjegg] created the Cookie Launcher. At the touch of a button, a door opens and the tin launches a cookie (and perhaps a few crumbs) skyward. Catching it is up to the operator, but since the tin can hold up to 40 cookies at once (39 in a magazine and 1 in the launcher), there’s enough to get some practice in.

The design is a real thing of beauty, from the rotary cookie holder to the ejector. Individual cookies are held in a pan-style magazine that rotates until a tasty disk is lined up with the ejector. The red separators aren’t just for show, either. The little inward protrusion on each one interacts with an optical sensor to ensure the system always knows when things are lined up.

The launcher design is pretty neat, too. There’s a platform that uses two smooth bolts as guides, and elastic bands to store energy. A motor cranks it downward, where it locks into place. The rotary magazine then turns to line up a cookie, which gravity feeds into the launcher by rolling down an incline. When a cookie is in place, a door in the lid opens and the launcher platform releases, sending the cookie skyward.

The original concept for the Cookie Launcher involved voice activation, but training the voice module to trigger on custom Norwegian commands wasn’t very reliable. Luckily, a button is far more obedient. It may be a bit less magical to use, but in our opinion the physicality of a button push meshes perfectly well with the requirement to catch your own cookie.

You can get a good look at the operation and a detailed tour of the insides in the video, embedded below. Thanks to [Rohit] for sending in the tip!

If airborne cookies aren’t your bag, check out one a very different approach to hands-free cookie dispensing.

Continue reading “Cookie Launcher Makes You Catch Your Own Snack” →

Treating Functions As Vectors In Hilbert Space

December 25, 2025 by Maya Posch 5 Comments

Perhaps the most beautiful aspect of mathematics is that it applies to literally everything, even things that do not exist in this Universe. In addition to this there are a number of alternative ways to represent reality, with Fourier space and its related transforms being one of the most well-known examples. An alternative to Euclidian vector space is called Hilbert space, as a real or complex inner product space, which is used in e.g. mathematical proofs. In relation to this, [Eli Bendersky] came up with the idea of treating programming language functions as vectors of a sort, so that linear algebra methods can be applied to them.

Of course, to get really nitpicky, by the time you take a function with its arguments and produce an output, it is no longer a vector, but a scalar of some description. Using real numbers as indices also somewhat defeats the whole point and claim of working in a vector space, never mind Hilbert space.

As with anything that touches upon mathematics there are sure to be many highly divisive views, so we’ll leave it at this and allow our esteemed readers to flex their intellectual muscles on this topic. Do you think that the claims made hold water? Does applying linear algebra to every day functions make sense in this manner, perhaps even hold some kind of benefit?

Redneck Spaceship From Trash

December 25, 2025 by Al Williams 7 Comments

Facebook Marketplace provides you with a free grain silo, so what do you do with it? If you are [saveifforparts], you mix it with other materials and produce a retro-style rocket ship prop. Art project? Sure, we’ll call it that.

We have to admit, we also see rockets in everyday objects, and the silo does look the part. He also had some junk that looked like a nose cone, some tanks, and other assorted trash.

Continue reading “Redneck Spaceship From Trash” →

FibreSeeker 3: Continuous Carbon Fiber Vs Chopped CF

December 25, 2025 by Maya Posch 6 Comments

Although you can purchase many types of FDM filaments containing ‘carbon fiber’ these days, they are in no way related to the carbon fiber (CF) composite materials used for rocket hulls and light-weight bicycles. This is because the latter use continuous fibers, often in weaved CF mats, whereas the FDM filaments just use small, chopped, fragments of CF. Obviously this will not result in the same outcome, which makes it interesting that a company called Fibre Seek is now running a KickStarter for a very affordable co-extrusion FDM printer that can add continuous CF to any part. They also sent a few test parts to [Dr. Igor Gaspar] for testing against regular FDM CF prints.

It should be noted here that continuous CF with FDM is not new, as Markforged already does something similar, though at a ‘Contact us for a price quote’ level. The advantage of the Fibre Seek solution is then the co-extrusion that would make printing with continuous CF much more flexible and affordable. Based on the (sponsored) [CNC Kitchen] video of a few weeks ago at a tradeshow, the FibreSeeker 3 printer is effectively a standard CoreXY FDM printer, with the special co-extrusion dual print head that allows for CF to be coated with the target thermoplastic before being printed as normal.

Continue reading “FibreSeeker 3: Continuous Carbon Fiber Vs Chopped CF” →

Born To Burn: The Battle Born LFP Battery

December 25, 2025 by Maya Posch 36 Comments

Would you feel confident in buying US-made LiFePO₄ (LFP) batteries? While the answer here is generally expected to be ‘yes’, especially compared to getting an unbranded LFP battery off eBay from a random seller, the outcome may not be that different. Case in point the 100 Ah, 12 VDC LFP Battle Born battery that [Will Prowse] took a look at to see why its positive terminal gets positively crispy.

Battle Born battery positive terminal. (Credit: Will Prowse, YouTube)

Once the lid was cut off, it’s easy to see what the problem is: the positive terminal is only loosely attached to the bus bar, leading to extremely poor contact. It also appears that there’s a plastic spacer which has properly melted already in this well-used battery that [Will] obtained from a viewer.

This overheating issue with Battle Born batteries has been reported for years now, which makes it a great idea to take a good look at any Battle Born LFP batteries you may have kicking around, as they may be plagued by the same design flaw. Trying to make use of the manufacturer’s warranty could be complicated based on the commentators in the DIY Solar Forum thread, as Battle Born likes to claim that the overheating issue is an external problem and not a design flaw.

Either way, it looks like an incredibly sketchy way to design a battery terminal on an LFP battery that is supposed to surge 100+A. [Will] is requesting that anyone affected posts details in the forum or similar to get all information together, as he looks to push Battle Born on this issue.

What makes this issue worse is that shortly after releasing that first video, Battle Born responded to some concerned customers with a response that claims that their terminal design is a ‘thermal fail-safe’, but as can be seen in [Will]’s follow-up video, it absolutely doesn’t look like one.

Continue reading “Born To Burn: The Battle Born LFP Battery” →

Twelve Days Of Christmas As Performed By 1980s Speech Chip

December 25, 2025 by Tyler August 5 Comments

In a curious historical twist, the “Twelve days of Christmas” are actually the days of revelry that followed the 25th. The preceding period, Advent, was traditionally a fast, not unlike Lent. When and why a fast became an excuse for chocolate calendars we cannot say, but this historical information is presented to explain that this great hack by [Kevin], making a vintage speech synthesizer chip sing the classic carol will remain relevant at least until January 5th — or perhaps even the 19th, for the Orthodox amongst us.

The chip in question is an SP0256A-AL2, which you may remember from various speech projects for 8-bit computers back in the day. It can talk, after a fashion, by reproducing 56 “allophones” — the sounds that make up English speech — from ROM. Singing, though? We cannot recall much of that back in the day, but then, a talking computer was impressive enough.

As it turns out this is building on an earlier hack [Kevin] did in which he used an Arduino to make the venerable speech chip MIDI controllable. In that project’s write-up it is revealed that a Si5351 programmable clock module is used to give a variable pitch signal to the speech synthesizer. In this way he’s able to get about an octave an a half, which is good enough when the carol in question only spans one octave.

Of course the pitch signal needs to be varied by something and for that the venerable Arduino once again takes the place of an 8-bit computer. In this case it’s pre-programmed, but can also be set up for MIDI control.Of course nothing says you can’t use true retro hardware or a more-capable RP2040 instead of the Amtel chip.

It’s sad to think how much compute power has been wasted this year on AI-generated novelty carols when a little bit of 1980s silicon and some ingenuity can do nearly as good — or better, depending on your tastes. Continue reading “Twelve Days Of Christmas As Performed By 1980s Speech Chip” →