Help with Trailer 2 axis weldable coupler

[Lylerocks]

Hello all. I have a BoB single wheel trailer that I am customizing from a axel mounted trailer to a seatpost mounted trailer. Easy peazy, except for one part. I need a 2 axis u type joint similar but does not have to be this one pictured. Any simple 2 axis articulating joint will work. I dont know what it might be called to find one??? The blue bike with trailer is my project the close up is what I am looking for so I can weld a bar on this trailer and get going. Apreciate your time and imput.

 

[J.R.]

Wouldn't a ball hitch allow for the movement you want?

https://www.amazon.com/dp/B00K3LQA46/ref=cm_sw_r_apa_i_zk.1EbQV3TPVE

Robot or human?

 

[Lylerocks]

No because its a single wheel BoB type trailer. If I am attaching to my seat post this is what I need to keep it from canting. A ball the trailer would flop around.

 

[Lylerocks]

J.R. thats a cool ball hitch by the way. Might look to that when I get a beafier 2 wheel trailer for other applications. Thanks.