Custom box for lock
I wanted to add a dedicated storage compartment for my very heavy (5 kg / 12 lb) chain lock. I thought right behind the seat would be ideal, as it wouldn't bounce around as much as near the wheels, and wouldn't interfere with me or with my kids, or require sharing any of the other storage that I had on the bike.
I 3d scanned my bike, and then tested a couple of prototypes, and then built this. I only have a small 3d printer, so this is about as big as I could make it. It's a bit of a tight fit, but works out ok. I printed it in PETG, which should stay in good shape, even in the sun. (Eg versus PLA.) You have to print the basket and then the feet separately, and then glue the feet onto the basket. Then you can stick it on your bike, and it zip ties into place. Seems to be working out well!
Happy to share the Fusion design file if anyone is interested!