Hi there and thank you for your enquiry via the community!
Developing such a releaser and finding the parts that work together is quite a task. Once it's printed, assembling it and getting it to work are nontrivial tasks as well.
Many things can go wrong and prevent you from having a working CanSat releaser. That's why at the moment we do not make the files available. Instead, we could look into manufacturing them for you. If that is an option for you, please kindly send an email with the number of releasers you are looking to buy to firstname.lastname@example.org and we will reply with a quotation.