Universal Joint for 13mm & 16mm Tubing

I needed a universal joint for the trolling motor tiller handle extension and was unable to find one on thingiverse in a hurry so I remodeled the u-joint design found in the awesome kayak rudder setup published by @LoboCNC.
I want to eventually remix the rudder assembly for use on my canoe and am even considering using a decent sized stepper and/or gear-reduction for an electronically controlled (steered) rudder.

The spider will connect to the two u-joint parts using 3mm screws (roughly 20m