The chimes are made out of 1-1/4" square tubing with 1/16" wall thickness. Tube lengths are 20", 17-7/8", 16-3/8", 14-5/8". I had a 20" tube lying around so I chose that as the longest piece and computed the lengths for the remaining three (and rounded them off to the nearest 8th inch). Supposedly and theoretically, given these lengths, they should play the notes C, E, G, B. The fact that these are not new tubing, with welds and dents and holes means there will be variations in the sound they produce. The nodes (point at which the tube is not vibrating) are located at 22.4% from the ends of the tube. These are where the holes have been drilled and the tubes hung by.
The sail / windcatcher had been a headache since the beginning. Tried several types of materials after I hung this thing up on the eaves: plastic film from a sack, plastic roofing material, cardboard. The latter was the most effective but it's hardly rain-proof. Then while having lunch it hit me that the floppy disks I have lying around would probably be a perfect choice. If one wasn't enough I could daisy chain them to increase the surface area. Turned out to be a great idea. The disks are light and waterproof (except for the liner inside I think).