Connect a trailer to your bike.

It needs a flexible coupling so that you can go around corners. This setup uses 32mm i/d radiator hose.

The thing here is a suitable connector to put on your bike to connect this flexible hose to.

The hose just slides on/off, a pin through the hose and "thing" prevents the hose sliding off in use. I use a padlock which also prevents some scallywag running off with your trailer when the bike is parked up.

Bolts shown A2 stainless steel M6x20. These screw into A2 stainless steel domed nuts.

There is a significant amount of support structure generated, Clean it all off and sand down to a smooth finish.

This is work-in-progress. Several years ago I had a trailer with a similar (steel) hitch and it lasted for years. I do not yet know how durable this plastic version will be. I made mine from PLA.