pet

41 Articles

Deceptively Simple Process Turns Bottles Into Filament

August 25, 2021 by 68 Comments

If you know that most soda bottles are made from PET plastic, you’ve probably thought about how you could make filament from them and have an endless supply of cheap printing material. [Mr3DPrint] says he has a method and shares a few videos that make it look easy. We wonder if the quality of the filament is up to par with commercial products, but assuming the videos are accurate, it appears that the resulting filament gets the job done.

The details are a little sketchy, but it looks simple enough. THe first step is to get any indentations out of the bottle. He has several demonstrations of this some using pressurized air in the bottle and some without. In each case, though, a drill holds the bottle through the cap and spins it over a flame until the surface is smooth.

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“Paper” Bottles For Your Fizzy Drinks (And Bottle Rockets)

April 23, 2021 by 144 Comments

A story that passed almost unnoticed was that the Coca-Cola company plan to run a limited trial of paper bottles. Wait, paper for a pressurized beverage? The current incarnation still uses a plastic liner and cap but future development will focus on a “bio-based barrier” and a bio composite or paper cap tethered to the vessel.

Given that plastic pollution is now a major global concern this is interesting news, as plastic drinks bottles make a significant contribution to that problem. But it raises several questions, first of all why are we seemingly unable to recycle the bottles in the first place, and given that we have received our milk and juice in paper-based containers for decades why has it taken the soda industry so long?

Plastic soft drink bottles are made from Polyethylene terephthalate or PET, the same polyester polymer as the one used in Dacron or Terylene fabrics. They’re blow-moulded, which is to say that an injection-moulded preform something like a plastic test tube with a screw top fitting is expanded from inside in a mould by compressed gas. As anyone who has experimented with bottle rockets will tell you, they are immensely strong, and as well as being cheap to make and transport they are also readily recyclable when separated from their caps.

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Hamster Goes On Virtual Journey

April 9, 2021 by 19 Comments

Hamsters are great pets, especially for those with limited space or other resources. They are fun playful animals that are fairly easy to keep, and are entertaining to boot. [Kim]’s hamster, [Mr. Fluffbutt], certainly fits this mold as well but [Kim] wanted something a little beyond the confines of the habitat and exercise wheel and decided to send him on a virtual journey every time he goes for a run.

The virtual hamster journey is built on an ESP32 microcontroller which monitors the revolutions of the hamster wheel via a hall effect sensor and magnet. It then extrapolates the distance the hamster has run and sends the data to a Raspberry Pi which hosts a MQTT and Node.js server. From there, it maps out an equivalent route according to a predefined GPX route and updates that information live. The hamster follows the route, in effect, every time it runs on the wheel. [Mr Fluffbutt] has made it from the Netherlands to southeastern Germany so far, well on his way to his ancestral home of Syria.

This project is a great way to add a sort of augmented reality to a pet hamster, in a similar way that we’ve seen self-driving fish tanks. Adding a Google Streetview monitor to the hamster habitat would be an interesting addition as well, but for now we’re satisfied seeing the incredible journey that [Mr Fluffbutt] has been on so far.

PET 2001 Emulator On $2 Of Hardware

December 9, 2020 by 20 Comments

Since the late 60s, Moore’s law has predicted with precision that the number of semiconductors that will fit on a chip about doubles every two years. While this means more and more powerful computers, every year, it also means that old computers can be built on smaller and cheaper hardware. This project from [Bjoern] shows just how small, too, as he squeezes a PET 2001 onto the STM32 Blue Pill.

While the PET 2001 was an interesting computer built by Commodore this project wasn’t meant to be a faithful recreation, but rather to test the video output of the Blue Pill, with the PET emulation a secondary goal. It outputs a composite video signal which takes up a good bit of processing power, but the PET emulation still works, although it is slightly slow and isn’t optimized perfectly. [Bjoern] also wired up a working keyboard matrix as well although missed a few wire placements and made up for it in the software.

With his own home-brew software running on the $2 board, he has something interesting to display over his composite video output. While we can’t say we’d emulate an entire PC just to get experience with composite video, we’re happy to see someone did. If you’d like to see a more faithful recreation of this quirky piece of computing history, we’ve got that covered as well.

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Who Says Solder Paste Stencils Have To Be CNC Cut?

December 9, 2020 by 19 Comments

Imagine having a surface mount kit that you’d like to stencil with solder paste and reflow solder, but which doesn’t come with a solder stencil. That was what faced [Honghong Lu], and she rose to the challenge by taking a piece of PET sheet cut from discarded packaging and hand-cutting her own stencil. It’s not a huge kit, the Technologia Incognita 2020 kit, but her home-made stencil still does an effective job.

So how does one create a solder stencil from household waste? In the video we’ve put below the break, she starts with her packaging, and cuts from it a square of PET sheet. It’s 0.24mm thick, which is ideal for the purpose. She then lays it over the PCB and marks all the pads with a marker pen, before cutting or drilling the holes for the pads. The underside is then sanded to remove protruding swarf, and the stencil can then be used in the normal way. She proves it by stenciling the solder paste, hand placing the parts, and reflowing the solder on a hotplate.

It’s clear that this is best suited to smaller numbers of larger components, and we’ll never use it to replace a laser-cut stencil for a thousand tiny 0201 discretes. But that’s not the point here, it’s an interesting technique for those less complex boards, and it’s something that can be tried by anyone who is curious to give stenciling and reflowing a go and who doesn’t have a project with a ready-cut stencil. And for that we like it.

Making your own stencils doesn’t have to include this rather basic method. They can be etched, or even 3D printed.

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Twenty Five Years Since The End Of Commodore

May 2, 2019 by 81 Comments

This week marks the twenty-five year anniversary of the demise of Commodore International. This weekend, pour one out for our lost homies.

Commodore began life as a corporate entity in 1954 headed by Jack Tramiel. Tramiel, a Holocaust survivor, moved to New York after the war where he became a taxi driver. This job led him to create a typewriter repair shop in Bronx. Wanting a ‘military-style’ name for his business, and the names ‘Admiral’ and ‘General’ already taken, and ‘Lieutenant’ simply being a bad name, Tramiel chose the rank of Commodore.

Later, a deal was inked with a Czechoslovakian typewriter manufacture to assemble typewriters for the North American market, and Commodore Business Machines was born. Of course, no one cares about this pre-history of Commodore, for the same reason that very few people care about a company that makes filing cabinets. On the electronics side of the business, Commodore made digital calculators. In 1975, Commodore bought MOS, Inc., manufacturers of those calculator chips. This purchase of MOS brought Chuck Peddle to Commodore as the Head of Engineering. The calculators turned into computers, and the Commodore we know and love was born.

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Redeem Your Irresponsible 90s Self

October 18, 2018 by 5 Comments

If you were a youth in the 90s, odds are good that you were a part of the virtual pet fad and had your very own beeping Tamagotchi to take care of, much to the chagrin of your parents. Without the appropriate amout of attention each day, the pets could become sick or die, and the only way to prevent this was to sneak the toy into class and hope it didn’t make too much noise. A more responsible solution to this problem would have been to build something to take care of your virtual pet for you.

An art installation in Moscow is using an Arduino to take care of five Tamagotchis simultaneously in a virtal farm of sorts. The system is directly wired to all five toys to simulate button presses, and behaves ideally to make sure all the digital animals are properly cared for. Although no source code is provided, it seems to have some sort of machine learning capability in order to best care for all five pets at the same time. The system also prints out the statuses on a thermal printer, so you can check up on the history of all of the animals.

The popularity of these toys leads to a lot of in-depth investigation of what really goes on inside them, and a lot of other modifications to the original units and to the software. You can get a complete ROM dump of one, build a giant one, or even take care of an infinite number of them. Who would have thought a passing fad would have so much hackability?

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