Made an Albi rudder

[Robert.Larman]

Hi, starting a new thread so as not to hijack another.
I recently made a new rudder for our Albi, replaced the steering quadrant bearing and made new fitting for the top of the rudder shaft. I made the new fitting from stainless due to the threads being damaged as these hold the entire assembly up into the hull.

I made the rudder by copying the shape from our original cracked and damaged one. Someone had also done some pretty shoddy re-riveting not using counter-sunk (flush) rivets. I started with 'O' state (soft) 6061 grade aluminium due to british standard ali being hard to come by over here. It had to be very soft to allow for the sharp bend at the front of the rudder without cracking. Once I had the basic shape and holes drilled I heat treated it to 6061 T6. This is extremely hard so the rudder won't bend whilst in the water. I had to rivet it together after it was heat treated otherwise it kept trying to distort the ali. The black rings around the rivet heads are polish residue from the polishing wheel.

Regards

Rob

[Sham]

Nice move creating a new topic.

Great job, looks really like an original one.
Is the top cavitation plate riveted on as well? I can't see how it is fixed?
Rivets are "flush" (counter sunk) on one side, how about the other?
I suppose the shaft is bevelled (not sure the right word...) at the bottom, inside the blade?

Sorry for all the question, I'm trying to get as much info as I can!

[Robert.Larman]

Yes, the anti-cavitation plate is riveted on as well. It's countersunk on top and formed rivet heads on the bottom. I did it this way because the rivet miller (tool to 'shave' the rivet flush) was too big to fit in close to the bend. Next time if I made another I would spend more time and make them flush.
All the rivets around the blade and the ones which fix the shaft in are counter sunk both sides. I think the ali was 0.063"in but unsure as I don't have the boat here to meausre. Anti cavitation plate was 0.120"in thick.

Yes the bottom of the shaft has a machined chamfer giving the shape to the rudder.

I'm also planning on putting some corrosion preventative (Dinitrol AV100 - stuff we use on aircraft) on the inside as well before it goes in the water to seal the metal.

I too looked at making it like A series did (photo on other thread) as it does look realy nice all welded and sealed up, however we were trying to keep it close to original. Of course i'm just assuming that the one we had on it was the original!

Cheers

Rob