Can You Homebrew A Running Shoe?

October 25, 2024 by Dave Rowntree 8 Comments

Unless you spend all your time lounging on the sofa, you probably own at least one pair of shoes. But have you ever thought to make your own to improve some aspect of your life? YouTube channel Answer in Progress set out to do precisely that, but it didn’t quite work out.

When you (well, other people) get into running, it’s tempting to believe a lot of the shoe company hype and just drop hundreds of dollars on the latest ‘super shoe’ and hope that will help you break your target time. But do you actually need to buy into all this, or can you make something yourself? The project aimed to get the 5k time down significantly, at any cost, but primarily by cheating with technology. The team set out to look at the design process, given that there is indeed a fair amount of science to shoe design. Firstly, after a quick run, the main issues with some existing shoes were identified, specifically that there are a lot of pain points; feet hurt from all the impacts, and knees take a real pounding, too. That meant they needed to increase the sole cushioning. They felt that too much energy was wasted with the shoes not promoting forward motion as much as possible; feet tended to bounce upwards so that a rocker sole shape would help. Finally, laces and other upper sole features cause distraction and some comfort issues, so those can be deleted.

A thicker mid-sole allows for a rolled shape

The plan was to make a ‘sock’ shoe style, with an upper in one piece and stretchy enough to slip on without laces. The process started by wrapping the foot in cling film and then a few layers of duct tape to fix the shape. This was split down the top to extract the foot, open out the pattern, and transfer it to some nylon fabric. The outer profile was transferred and cut out with simple hand tools in a fashion that would allow the shape to be reconstructed as it was glued to a sole. It sounds simple, but it’s pretty fiddly work.
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‘Upgrading’ A Microwave Oven To 20 KW

October 25, 2024 by Dave Rowntree 38 Comments

Whilst microwave plasmas are nothing new around here, we were curious to see what happens at 20x the power, and since YouTuber [Styropyro] had put out a new video, we couldn’t resist seeing where this was going. Clearly, as your bog standard microwave oven can only handle at most one kilowatt; the ‘oven’ needed a bit of an upgrade.

A 16 kW water-cooled magnetron. Why not over-drive it to 20 kW for fun?

Getting hold of bigger magnetrons is tricky, but as luck — or perhaps fate — would have it, a 16 kW, water-cooled beast became available on eBay thanks to a tip from a Discord user. It was odd but perhaps not surprising that this Hitatch H0915 magnetron was being sold as a ‘heat exchanger.’

[Styropyro] doesn’t go into much detail on how to supply the anode with its specified 16 kW at 9.5 kVDC, but the usual sketchy (well down-right terrifying) transformers in the background indicate that he had just what was needed kicking around the ‘shop. Obviously, since this is a [Styropyro] video, these sorts of practical things have been discussed before, so there is no need to waste precious time and get right on to blowing stuff up!

Some classic microwave tricks are shown, like boiling water in five seconds, cooking pickles (they really do scream at 20 kW) and the grape-induced plasma-in-a-jar. It was quite clear that at this power level, containing that angry-looking plasma was quite a challenge. If it was permitted to leak out for only a few seconds, it destroyed the mica waveguide cover and risked coupling into the magnetron and frying it. Many experiments followed, a lot of which seemed to involve the production of toxic brown-colored nitrogen dioxide fumes. It was definitely good to see him wearing a respirator for this reason alone!

Is it purple or is it indigo? Beauty is in the eye of the beholder!

The main star of the demonstration was the plasma-induced emissions of various metal elements, with the rare indigo and violet colors making an appearance once the right blend of materials was introduced into the glassware. Talking of glassware, we reckon he got through a whole kitchen’s worth. We lost count of the number of exploded beakers and smashed plates. Anyway, plasma science is fun science, but obviously, please don’t try any of this at home!

For those who didn’t take an ‘electron devices’ course at college, here’s a quick guide to how magnetrons work. Plasma physics is weird; here’s how the plasma grape experiment works. Finally, this old hack is a truly terrible idea. Really don’t do this.

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Putting The New CryoGrip Build Plate To The Test

October 25, 2024 by Dave Rowntree 14 Comments

BIQU has released a new line of low-temperature build plates that look to be the next step in 3D printing’s iteration—or so YouTuber Printing Perspective thinks after reviewing one. The Cryogrip Pro is designed for the Bambu X1, P1, and A1 series of printers but could easily be adapted for other magnetic-bed machines.

The bed adhesion strength when cold is immense!

The idea of the new material is to reduce the need for high bed temperatures, keeping enclosure temperatures low. As some enclosed printer owners may know, trying to print PLA and even PETG with the door closed can be troublesome due to how slowly these materials cool. Too high an ambient temperature can wreak havoc with this cooling process, even leading to nozzle-clogging.

The new build plate purports to enable low, even ambient bed temperatures, still with maximum adhesion. Two versions are available, with the ‘frostbite’ version intended for only PLA and PETG but having the best adhesion properties. A more general-purpose version, the ‘glacier’ sacrifices a little bed adhesion but gains the ability to handle a much wider range of materials.

An initial test with a decent-sized print showed that the bed adhesion was excellent, but after removing the print, it still looked warped. The theory was that it was due to how consistently the magnetic build plate was attached to the printer bed plate, which was now the limiting factor. Switching to a different printer seemed to ‘fix’ that issue, but that was really only needed to continue the build plate review.

They demonstrated a common issue with high-grip build plates: what happens when you try to remove the print. Obviously, magnetic build plates are designed to be removed and flexed to pop off the print, and this one is no different. The extreme adhesion, even at ambient temperature, does mean it’s even more essential to flex that plate, and thin prints will be troublesome. We guess that if these plates allow the door to be kept closed, then there are quite a few advantages, namely lower operating noise and improved filtration to keep those nasty nanoparticles in check. And low bed temperatures mean lower energy consumption, which is got to be a good thing. Don’t underestimate how much power that beefy bed heater needs!

Ever wondered what mini QR-code-like tags are on the high-end build plates? We’ve got the answer. And now that you’ve got a pile of different build plates, how do you store them and keep them clean? With this neat gadget!

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Hands On With A Giant Nixie Tube

October 24, 2024 by Dave Rowntree 9 Comments

[Sam Battle] is no stranger to these pages, nor is his Museum is not Obsolete. The museum was recently gifted an enormous Nixie tube created by Dalibor Farný, a B-grade (well, faulty) unit that could not be used in any of their commissioned works but was perfectly fine for displaying in the museum’s retro display display. This thing is likely the largest Nixie tube still being manufactured; although we read that it’s probably not the largest ever made, it’s still awesome.

Every hacker should have their own museum.

It is fairly simple to use, like all Nixie tubes, provided you’re comfortable with relatively high DC voltages, albeit at a low current. They need a DC voltage because if you drive the thing with AC, both the selected cathode digit plate and the anode grid will glow, which is not what you need.

Anyway, [Sam] did what he does best, clamped the delicate tube in some 3D printed mounts and hooked up a driver made from stuff he scraped out of a bin in the workshop. Obviously, for someone deeply invested in ancient electromagnetic telephone equipment, a GPO (British General Post Office, now BT) uniselector was selected, manually advanced with an arcade-style push button via a relay. This relay also supplies the ~140 V for the common anode connection on the Nixie tube. The individual digit cathodes are grounded via the uniselector contacts. A typically ancient GPO-branded snubber capacitor prevents the relay contacts from arcing over and ruining the display unit. There isn’t much more to it, so if you’re in the Ramsgate, UK, area anytime soon, you can pop in and play with it for yourself.

Nixies are cool, we’ve covered Nixie projects for years, like this DIY project from ages ago. Bringing such things into the modern area is the current specialty of Dalibor Farný, with this nice video showing some of the workmanship involved. By the way — the eagle-eyed will have noticed that we covered this particular Nixie tube before, shown in the format of a large art installation. But it doesn’t hurt to get close up and play with it on the bench.\

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Seven New Street Fighter 2 Arcade Rom Hacks

October 23, 2024 by Dave Rowntree 2 Comments

[Sebastian Mihai] is a prolific programmer and hacker with a particular focus on retrocomputing and period games, and this latest hack, adding new gameplay elements to Capcom’s Street Fighter II – Champion Edition, is another great one. [Sebastian] was careful to resist changing the game physics, as that’s part of what makes this game ‘feel’ the way it does, but added some fun extra elements, such as the ability to catch birds, lob barrels at the other player, and dodge fire.

The title screen was updated for each of the different versions, so there is no doubt about which was being played. This work was based on their previous hacks to Knights of the Round. Since both games shared the same Capcom CPS-1 hardware, the existing 68000 toolchain could be reused, reducing the overhead for this new series of hacks. Continue reading “Seven New Street Fighter 2 Arcade Rom Hacks” →

A 3D Printed, Open Source Lathe?

October 23, 2024 by Dave Rowntree 35 Comments

[Chris Borge] has spent the last few years creating some interesting 3D printed tools and recently has updated their 3D printable lathe design to make a few improvements. The idea was to 3D print the outer casing of the lathe in two parts, adding structural parts where needed to bolt on motors and tool holders, and then fill the whole thing with concrete for strength and rigidity.

The printed base is initially held together with two lengths of studding, and a pile of bolts are passed through from below, mating with t-nuts on the top. 2020 extrusion is used for the motor mount. The headstock is held on with four thread rods inserted into coupling nuts in the base. The headstock unit is assembled separately, but similarly; 3D printed outer shell and long lengths of studding and bolts to hold it together. Decent-sized tapered roller bearings make an appearance, as some areas of a machine tool really cannot be skrimped. [Chris] explains that the headstock is separate because this part is most likely to fail, so it is removable, allowing it to be replaced.

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Tridora: A Full-Custom CPU Designed For Pascal

October 23, 2024 by Dave Rowntree 13 Comments

[Sebastian Lederer] has created Tridora: an unusual stack-based CPU core intended for FPGA deployment, co-developed with its own Pascal compiler. The 32-bit word machine is unusual in that it has not one but three stacks, 16-bit instruction words, and a limited ISA, more like those of the 8-bit world. No multiply or divide instructions will be found in this CPU.

The design consists of about 500 lines of Verilog targeting the Digilent Arty-A7 FPGA board, which is based around the Xilinx Artix-7 FPGA line. [Sebastian] plans to support the Nexys A7 board, which boasts a larger FPGA array but has less RAM onboard. The CPU clocks in at 83 MHz with four clock cycles per instruction, so over 20 MIPS, which is not so shabby for a homebrew design. Wrapped around that core are a few simple peripherals, such as the all-important UART, an SD card controller and a VGA display driver. On the software side, the Pascal implementation is created from scratch with quite a few restrictions, but it can compile itself, so that’s a milestone achieved. [Sebastian] also says there is a rudimentary operating system, but at the moment, it’s a little more than a loader that’s bundled with the program image.

The Tridora Gitlab project hosts the Verilog source, an emulator (written in Golang, not Pascal) and a suite of example applications. We see quite a few custom CPUs, often using older or less popular programming languages. Here’s an FPGA-based Forth machine to get you started. Implementing programming languages from scratch is also a surprisingly common hack. Check out this from-scratch compiler for the Pretty Laughable Programming language.