Getting Started With Polypropylene (PP) 3D Printing

September 6, 2024 by Maya Posch 25 Comments

Polypropylene (PP) is a thermoplastic that has a number of properties that sets it apart from other thermoplastics which see common use with 3D printing, including PLA, ABS and nylon (PA). Much like ABS (and the similar ASA), it is a pretty touchy material to print, especially on FDM printers. Over at the [All3DP] site [Nick Loth] provides a quick start guide for those who are interested in using PP with 3D printing, whether FDM, SLS or others.

A nice aspect of printing with PP is that it requires similar temperatures for the extruder (205 – 275 °C) and print bed (80 – 100 °C) as other common FDM filaments. As long as airflow can be controlled in the (enclosed) printer, issues with warping and cracking as the extruded filament cools should not occur. Unlike ABS and ASA which also require an enclosed, temperature-controlled printing space, PP has an advantage that printing with it does not produce carcinogenic fumes (styrene, acrylonitrile, etc.), but it does have the issue of absolutely not wanting to adhere to anything that is not PP. This is where the article provides some tips, such as the use of PP-based adhesive tape on the print bed, or the use of PP-based print plates.

As far as PP longevity and recyclability goes, it compares favorably with ABS and PA, meaning it’s quite resilient and stable, though susceptible to degradation from UV exposure without stabilizers. Recycling PP is fairly easy, though much like with polymers like PLA, the economics and logistics of recycling remain a challenge.

Bluetooth Version 6.0 Core Specification Released

September 6, 2024 by Maya Posch 15 Comments

The Bluetooth SIG recently released the core specification for version 6.0 of Bluetooth. Compared to 5.x, it contains a number of changes and some new features, the most interesting probably being Channel Sounding. This builds upon existing features found in Bluetooth 5.x to determine the angle to, and direction of another device using Angle of Arrival (AoA) and Angle of Departure (AoD), but uses a new approach to much more precisely determine these parameters. as defined in the Technical Overview document for this feature.

In addition to this feature, there are also new ways to filter advertising packets, to reduce the number of packets to sift through (Decision-Based Advertising Filtering) and to filter out duplicate packets (Monitoring Advertisers). On a fundamental level, the Isochronous Adaptation Layer (ISOAL) received a new framing mode to reduce latency and increase reliability, alongside frame spacing now being negotiable and additional ways to exchange link layer information between devices.

As with any Bluetooth update, it will take a while before chipsets supporting it become widely available, and for the new features to be supported, but it gives a glimpse of what we can likely expect from Bluetooth-enabled devices in the future.

Hot Water Heater Hacked To Run On Solar Juice

September 6, 2024 by Lewin Day 39 Comments

It’s 2024, and there’s no getting around it. Grid energy is expensive. [Darrell] realized that a lot of his money was going on water heating, and he came up with a neat solution. What if he could hack in some solar power to slash his bills at a minimum of fuss? It worked so well for him, he’s whipped up a calculator to help others do the same.

[Darrell]’s idea was simple enough. He hooked up solar panels to just the bottom heating element of his hot water heater. This cut his power bill in half. His calculator is now up at pvh20.com, and it’s designed to help you figure out if it’s feasible for you. It takes into account your location, local power prices, and the amount of sun your area tends to get on a regular basis. It also takes into account the solar panels you intend to use and your water heater to determine how many panels you’ll need for properly hot water. Key all that in, and you’re well on your way to speccing a decent solar hot water setup. From there you’ll just need to buy the right stuff and wire it all up properly.

If you live in an area where the sun shines freely and the power is more expensive than printer ink, this could be a project well worth pursuing. Cheaper hot water is a grand thing, after all. [Darrell’s] calculator is really only the first step, and it doesn’t deal with the practicalities of installation, but that’s half the fun of a good project, right? Happy hacking!

An Automatic Cat Feeder Built With A 4060 Binary Counter

September 6, 2024 by Lewin Day 14 Comments

We’ve seen a great many cat feeders over the years. Some rely on the Internet of Things, and some rely on fancy microcontrollers. [Larry Cook], on the other hand, built his using a simple 4060 binary counter chip.

The feeder is built out of old plywood, and the whole thing runs off an old 12-volt DC wall wart and a lead-acid battery to keep it going in a power outage. The dry cat food is stored in hopper above a drum, with the drum rotated by a 12-volt DC gearmotor. The gearmotor is activated on a schedule—either every 4 hours, or every 5.5 hours, depending on setting. There’s then a four-digit 7-segment display for counting the total number of feedings.

The manner of operation is simple. The 4060 binary counter slowly counts up to 8,196 on a 1.11 Hz or 0.83 Hz clock, for four hour or 5.5 hour operation respectively. When it hits that threshold, it fires the gear motor. The gear motor then rotates the drum for one revolution, dumping a preset amount of food. At the end of a revolution, it triggers a hall sensor which resets the circuit.

The best thing about this design? It’s been in service for ten years. [Larry’s] original video is a big contrast to his latest one, but it shows the same feeder doing the same job, all this time.

We love a good cat feeder, and it’s great to see one built with simple old-school parts, too. Video after the break.

Continue reading “An Automatic Cat Feeder Built With A 4060 Binary Counter” →

How Much Resolution Does Film Really Have?

September 6, 2024 by Lewin Day 27 Comments

Have you ever scanned old negatives or print photographs? Then you’ve probably wondered about the resolution of your scanner, versus the resolution of what you’re actually scanning. Or maybe, you’ve looked at digital cameras, and wondered how many megapixels make up that 35mm film shot. Well [ShyStudios] has been pondering these very questions, and they’ve shared some answers.

The truth is that film doesn’t really have a specific equivalent resolution to a digital image, as it’s an analog medium that has no pixels. Instead, color is represented by photoreactive chemicals. Still, there are ways to measure its resolution—normally done in lines/mm, in the simplest sense.

[ShyStudios] provides a full explanation of what this means, as well as more complicated ways of interpreting analog film resolution. Translating this into pixel equivalents is messy, but [ShyStudios] does some calculations to put a 35mm FujiColor 200 print around the 54 megapixel level. Fancier films can go much higher.

Of course, there are limitations to film, and you have to use it properly. But still, it gives properly impressive resolution even compared to modern cameras. As it turns out, we’ve been talking about film a lot lately! Video after the break.

Continue reading “How Much Resolution Does Film Really Have?” →

Ask Hackaday, What’s Next?

September 6, 2024 by Jenny List 39 Comments

Writing for Hackaday involves drinking from the firehose of tech news, and seeing the latest and greatest of new projects and happenings in the world of hardware. But sometimes you sit back in a reflective mood, and ask yourself: didn’t this all used to be more exciting? If you too have done that, perhaps it’s worth considering how our world of hardware hacking is fueled, and what makes stuff new and interesting.

Hardware projects are like startup fads

An AliExpress page of Nixie clock kits — When AliExpress has hundreds of kits for them, Nixie clocks are a mature project sector, by any measure.

Hardware projects are like startup fads, they follow the hype cycle. Take Nixie clocks for instance, they’re cool as heck, but here in 2024 there’s not so much that’s exciting about them. If you made one in 2010 you were the talk of the town, in 2015 everyone wanted one, but perhaps by 2020 yours was simply Yet Another Nixie Clock. Now you can buy any number of Nixie clock kits on Ali, and their shine has definitely worn off. Do you ever have the feeling that the supply of genuinely new stuff is drying up, and it’s all getting a bit samey? Perhaps it’s time to explore this topic.

I have a theory that hardware hacking goes in epochs, each one driven by a new technology. If you think about it, the Arduino was an epoch-defining moment in a readily available and easy to use microcontroller board; they may be merely a part and hugely superseded here in 2024 but back in 2008 they were nothing short of a revolution if you’d previously has a BASIC Stamp. The projects which an Arduino enabled produced a huge burst of creativity from drones to 3D printers to toaster oven reflow and many, many, more, and it’s fair to say that Hackaday owes its early-day success in no small part to that little board from Italy. To think of more examples, the advent of affordable 3D printers around the same period as the Arduino, the Raspberry Pi, and the arrival of affordable PCB manufacture from China were all similar such enabling moments. A favourite of mine are the Espressif Wi-Fi enabled microcontrollers, which produced an explosion of cheap Internet-connected projects. Suddenly having Wi-Fi went from a big deal to built-in, and an immense breadth of new projects came from those parts. Continue reading “Ask Hackaday, What’s Next?” →

Hackaday Podcast Episode 287: Raspberry Pi Woes, Blacker Than Black, And Printing With Klipper

September 6, 2024 by Al Williams No comments

Elliot Williams is back from vacation, and he and Al Williams got together to talk about the best Hackaday posts from the last week. Of course, the Raspberry Pi RP2350 problem generated a bit of discussion.

On a lighter note, they saw laser lawn care, rooting WiFi devices, and some very black material made from wood. Need more current-sinking capability from a 555? They talked about that, too, along with a keyboard you use with your feet.

The guys had a lot to say about Klipper, why you might want to move your 3D printer to it, and the FCC’s stance on ham radio antennas in restricted neighborhoods. Oh, and don’t forget to play “What’s that Sound?”