I'm rebuilding a 30' cruising cat
(30' cruising catamaran repair log
and have 1.5" round bar rudder shafts in 316L stainless. Living in very rural Alaska no one here has a mill that can cut keyways. My old rudder heads were aluminum with keyways so I had to protect against corrosion with goop as well as have keys. To get keyways cut into these new shafts I would need to ship to Anchorage where I can get the keyways cut for $200 for two shafts, but also would take a couple hundred to ship down and back.
Design isn't specific on this point but looks like a detail shows something not much more than a small section of pipe slipped over the shaft with a through bolt. I could do that myself - got the cobalt drill bits. Also a guy in town is good at tig welding stainless if I need to beef up any straps from head to tillers. I'll include a pic or two of old jury rigged system that worked under motor (never had it rigged for sail). I could still use this head without a key and just run a bolt or roll pin through it. It would clamp tight.
So looking for advice/pics of folks' rudder heads.
Second question - If I cut keyways or drill a through bolt, should I put ackermann geometry into that keyway/hole in relation to centerline of the rudder blade or just plan on bending inward each tiller, if that works?
Here's old head and tiller attachment, and a pic of James's boat steering system I'm shooting for similar: