A man with dark skin in a red shirt and khaki shorts sits in a chair. His left leg has a prosthetic below the knee. The upper half of the prosthethic is an off white plastic socket with flecks of different off white plastic throughout hinting at the recycled nature of the plastic. The lower half is a metal tube attached to an artificial foot in black sandals.

Precious Plastic Prosthetics

February 20, 2023 by Navarre Bartz 8 Comments

Plastic waste is a major problem, but what if you could turn the world’s trash into treasure? [Yayasan Kaki Kita Sukasada (YKKS)] in Indonesia is doing this by using recycled plastic to make prosthetic legs.

Polypropylene source material is shredded and formed into a sheet which is molded into the required shape for the socket. A layer of cloth and foam is used to cushion the interface between the patient and the socket itself. Using waste plastic to make parts for the prosthetics lowers the price for patients as well as helps to keep this material out of the landfill.

What makes this project really exciting is that [YKKS] employs disabled people who develop the prosthetics and also trains patients on how to maintain and repair their prosthetics with easily sourced tools and materials. With some medical device companies abandoning their devices, this is certainly a welcome difference.

We’ve previously covered the Precious Plastic machines used to make the plastic sheets and the organization’s developments at small scale injection molding.

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A round clock with a color-coded face, with its name "Pingo" across it, together with a 3D animated mouse

Pingo Is An Analog Clock That Uses Colors Instead Of Hands

February 20, 2023 by Robin Kearey 8 Comments

The purpose of a clock is to show the time, obviously. But if you’ve followed Hackaday for some time, you’ll know there are about a million different ways of achieving this. [illusionmanager] added yet another method in his Pingo Color Clock, which, as the name suggests, uses color as the main indicator.

The clock’s face is divided into three concentric circular zones. The zone at the center shows the hours, while the outer ring indicates the minutes. Both change their color such that they match the zone in between, which always shows a complete rainbow, at the desired location. In the picture above for example, the magenta inner circle matches the rainbow at the 10 o’clock position, while the yellow outer circle matches it at 10 minutes past the hour, meaning it’s currently 10:10.

The rainbow ring is also moving however, and by adjusting its rotation through time you can get some interesting effects. [illusionmanager] programmed it in such a way that the outer ring is always yellow during the day, purple at night, and red at sunrise and sunset. The overall brightness is also adjusted to a day/night schedule.

As complex as the clock’s appearance may be, inside it’s quite a simple design. Nine concentric circular LED strips are driven by an ESP8266, which retrieves the time and sunrise information through its WiFi connection. A piece of translucent white acrylic acts as a diffuser, while a 3D-printed enclosure holds everything together.

Encoding the time using different colors of light has been done before in various different ways, and while we haven’t seen Pingo in real life, we believe it should be somewhat easier to read than most of those examples. It might actually form a nice complement to a recent analog LED ring clock.

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