The rudders and flaps were cut in 2mm acrylic on my laser cutter, 2 of 3each made up a single rudder, this allowed the sandwiching of the rudder shaft and the pivot shaft between the sections and then bonding together. The brass tube had a flap soldered into to give extra leverage to the acrylic rather than just relying on the epoxy bonding the shaft. Using brass tube also allows a couple of small holes to be drilled at the top end so that oil can be squirted down it and it will lubricate between the shaft and the sleeve into the hull
Also you may notice some cracks in the acrylic, apparently it doesn't like being cleaned and degreased with alcohol, dunno why, but as they were all on the inside and didn't penetrate the full thickness, I used them.