An Autumn 2021 project to provide 10 sets of wearable lights for Peloton Liverpool Joy Ride winter cycling events (e.g. https://youtu.be/Y08svOdIMxA) produced by a group of volunteers from DoES Liverpool and Peloton Liverpool. It uses the MCQN My Bike's Got LED board which was originally designed by Adrian McEwen for lights attached to bike frames but is equally good for most situations involving battery powered addressable LEDs.
The lights consist of large circular disks on the front and back of each cyclist, attached with webbing straps. Each contains a disk of 93 addressable LEDs. The board and battery (4 x 18650) are in a waterproof(ish) pouch which is taped to the back of the front disk with VHB tape. Leads go from the board to the lights through holes in the back of the disks. These are taped over with plumbing tape to increase water resistance. The leads to the back disk are taped to one of the shoulder straps.
I started prototyping based on the children's backpacks shown on pages 10 and 11 of this document as these had been donated to DoES Liverpool. I quickly found that the combination of electrical leads and cross over straps made them very confusing to put on and ended up using separate straps for each shoulder and both sides of the body. I was able to reuse the webbing and clips from this project though, as well as some leftover hook and loop tape and marking tape from a visor project.
I vacuum formed the front face of the disks with help from Matt and Jimmy of the University of Liverpool School of Engineering (Matt is a member of the cycling group). The face of the front disks is made of 1mm thick white HIPS plastic giving a very diffused efffect to the lights underneath. The face of the back disks is made of 1mm clear PETG. The Engineering Department made a former from MDF which led to a slightly rough surface giving a slight but useful diffused effect to the clear side. The back face of all the disks was laser cut from 1mm HIPS. As this was quite thin, I decided to cut the front face to the same shape, hoping that this would help reinforce it.
Originally we were going to use strips of lights set out in a grid, but this turned out to be too time consuming and difficult to lay out and solder. We then ordered some disks in the form of concentric rings (similar to these. The ones we got had 93 lights. When they arrived, they had leads soldered on to each ring so that the rings could be split up and used separately. Although they worked like this, they wouldn't fit into the available space, so Paul H and Sean J desoldered them and resoldered them together. The light disks take less space than the original grid, but we decided to go ahead with the original size of container, as these had already been produced. In addition I tried a modified version of the attachment points, using vertical and horizontal attachments instead of diagonal - this was a slight improvement, but I decided to use the existing laser cut backs as these had alreday been made, and we might see need for further changes when they are in use.