PRBS Generator

This CAD model was designed by Oskar van Deventer, copyright (c), 23 December 2023.

PRBS Generator is a piece of kinetic art that mechanically generates a Pseudo-Random Binary Sequence (PRBS, https://en.wikipedia.org/wiki/Pseudorandom_binary_sequence ). When I learned about PRBS at my university, I designed a mechanism for it on 10 January 1987. The mechanism was as simple as the algorithm to generate a PRBS. It uses a shift register, where a new bit is the exclusive OR (XOR) of two earlier bits. I implemented this mechanism 37 years later, where the shift register is a set of seven "bits" on a rotating disk. At one point, a bit flips when its neighbour is "0", whereas it stays the same when the neighbour is "1". The flipping is pushed by gears at the bottom of a bit. The flipping is blocked when the neighbour is in its "1" state. Then the magnets decouple the rotation of the gear from the bit. The mechanism cycles through 127 different seven-bit sequences, only skipping the "1111111" sequence.

The mechanism uses 28 3x3-millimeter disk magnets: https://www.supermagnete.de/eng/disc-magnets-neodymium/disc-magnet-3mm-3mm_S-03-03-N and eight M3 flat cheese head screws.

Here are some links about this design.
https://www.youtube.com/watch?v=Cpiy-KPjsxI
https://i.materialise.com/en/shop/item/prbs-generator
https://www.shapeways.com/product/2AV7JT5GN/prbs-generator
https://i.materialise.com/forum/t/prbs-generator-by-oskar/3552
https://www.shapeways.com/forum/t/prbs-generator-by-oskar.102620/
https://twistypuzzles.com/forum/viewtopic.php?t=39220

Feel free to 3D-print an extra sample to give to a friend, as long as you mention the designer and don't charge money.

If you are planning to sell some samples, then please contact me for a license agreement. The royalty fee is 10% of your selling price.

Please do not upload the design to a commercial service, or redistribute the design in any way other than linking to the YouTube video: https://www.youtube.com/watch?v=Cpiy-KPjsxI

Enjoy!

Oskar
3 February 2024

Contact: 
https://oskarvandeventer.nl/index_contact.php?subject=Print%20It%20Yourself


