A quick connector for a bike trailer. So that the trailer can be switched between multiple bikes easily.
Not cumbersome and keeps the bike looking "normal". My wife and I live about two blocks from the grocery store and want to be able to use our bikes to get the goods. We have limited space were we store our bikes and the storage will not fit a trailer. I want my wife to be able to easily hook and unhook from the trailer while I am at work.

Using
1 X Male 3/8 pneumatic connector
1 X Female 3/8 pneumatic connector
2 X 1/4 (or smaller) eye bolts

Step 1: Disassemble the Female Connector

First you will need to disassemble the female pneumatic connector.
Using needle noose pliers reach into the threaded side of the connector and grab the spring and give a pull. The spring and another small piece will come out. You may discard them they will no longer be needed.

Before continuing note the action of the small ball bearings and the slide section of the Female connector.

Using some pliers and a wrench loosen/ split the connector. Do not attempt to work the slide while the connector is apart. Other wise you run the risk loosing the ball bearings. Set the slide section to the side until you are finished with fitting the eye bolt.

Step 2: Eye Bolt Work

Lay one of the eye bolts next to the threaded portion of the Female connector to see how much needs to be cut off/ if any. You will want the thread end of the bolt to be recessed in the connector so that it does not get in the way later

My bolt was too long so i had to cut it down.

Next the peaks of the nut for the eye bolt were just to tall so i had to file them down. Now the nut will drop all the way inside the connector. Now give the bolt a good tightening and it should be snug.
Now reassemble the female connector.

Get the other eye bolt and place in the vise in such a way so that you can open the eye. Take care of the threads. Bend open the eye and insert the Female connector eye bolt assembly. Then use the vice to close the eye.

Instead of using the second eye bolt you could substitute it with a U-bolt depending on your application.

Step 3: Male Connector Application

Depending on what bike you have, your frame rail type and how old your bike is this next step is different.

My bike has a large enough hole in the frame rail that i was able to insert the male connector by cutting down a fitting and using a washer to fill out the hole.

my wife's bike did not have this hole so i had to cut down the male connector and use a metric bolt to thread into; where i assume the disc brake caliper or a fender support would be bolted on. I have not yet tested this for strength. But I would think i could stand on this connector and it would hold.

Refer to these other Intructables if my poor directions are to lame. Because these guys gave me inspiration

https://www.instructables.com/id/Yet-Another-Bicycle-Trailer/?ALLSTEPS

https://www.instructables.com/id/DIY-bicycle-trailer/