C mount to Efm mount adapter modification sawing and mostly grinder manual hard work

I want to show you what sometimes i have to do to be able to use a c-mount lens on canon eosm.
The truth is that the majority of c-mount cctv lenses, surveillance cameras lenses are not working with the canon eosm.
The adapters available on the market needs to be modified or the lenses needs to be modified in order to be usable on a canon eosm & magic lantern.
Thank you! 👍🤝