3 ms·

I've been working on something similar for several years. (Alas, I don't have MIT's PR budget.) I call it "PinThing" and implement the pins as DC motor powered,

by hugs 11y ago

I've been working on something similar for several years. (Alas, I don't have MIT's PR budget.) I call it "PinThing" and implement the pins as DC motor powered, 3D printable linear actuators. I use limit switches to detect end-of-travel, and a shaft encoder to measure distance traveled. Current goal is to make an array of four 3x5 pin blocks to make a digital clock display. One of these days I really need to finish and formally publish this project! One big challenge in the project is driving down the cost per pin to make a large array affordable -- that's why I focus on using 3D printable parts and cheap motors. Here's a demo of one pin powered by Arduino and an H-bridge motor driver circuit: https://youtu.be/pLzDHLm01wM https://youtu.be/pLzDHLm01wM Three.js software demo: http://pinthing.com http://pinthing.com

gene-h 11y ago
well you can buy a chinese knock-off of the actuators the MIT people used from spark fun: https://www.sparkfun.com/products/10976 https://www.sparkfun.com/products/10976
- hugs 11y ago
  I'm trying to drive the cost down to $1-2 per pin. It's obvious the MIT team did not optimize for cost. At $20/pin (from the SparkFun link), a 28-pin display (the minimum you'd need for a 4 digit, 7-segment display clock would cost $560. To so anything interesting, you'd want dozens or hundreds of pins. Cost is a huge reason keeping this idea from being more wide-spread.
  - gene-h 11y ago
    Well if you really want to drive down the cost, the best thing to do would be to mass produce the actuators for the purpose. The actuators MIT used aren't really intended as actuators, they're some weird part for moving knobs around on high end audio equipment. Now as it turns out, there really are linear actuators that cost about $1 per actuator, they're just tiny: http://www.alibaba.com/product-detail/Goteck-1-5g-Super-Micro-Analog_60006747818.html http://www.alibaba.com/product-detail/Goteck-1-5g-Super-Micr...

by hugs 11y ago

gene-h 11y ago

well you can buy a chinese knock-off of the actuators the MIT people used from spark fun: https://www.sparkfun.com/products/10976 https://www.sparkfun.com/products/10976

hugs 11y ago
I'm trying to drive the cost down to $1-2 per pin. It's obvious the MIT team did not optimize for cost. At $20/pin (from the SparkFun link), a 28-pin display (the minimum you'd need for a 4 digit, 7-segment display clock would cost $560. To so anything interesting, you'd want dozens or hundreds of pins. Cost is a huge reason keeping this idea from being more wide-spread.
- gene-h 11y ago
  Well if you really want to drive down the cost, the best thing to do would be to mass produce the actuators for the purpose. The actuators MIT used aren't really intended as actuators, they're some weird part for moving knobs around on high end audio equipment. Now as it turns out, there really are linear actuators that cost about $1 per actuator, they're just tiny: http://www.alibaba.com/product-detail/Goteck-1-5g-Super-Micro-Analog_60006747818.html http://www.alibaba.com/product-detail/Goteck-1-5g-Super-Micr...