I’ve designed a collar that tightens around the top of the spray can using a zip tie or M4 nut and bolt, this mounting system coupled with an internal groove allows the handle to be perfectly secured to the spray can, without the risk of slipping and also makes the model really durable. To increase the durability further, the trigger is to be printed horizontally, and attaches to the handle with a M5x15mm bolt that acts as a pivot and a M5 nut.
If you don’t have a printer, you can print it from https://www.jawstec.com/3d-printing-service/ or another online printer.
Want to buy this item ready to use? Get it here:
https://www.etsy.com/listing/1092478613/spray-can-handle-to-end-them-all?ref=listings_manager_grid