PeterL3, I agree, a larger version would be great to see built.
Somewhere around 32", double the length of the original would make a really nice model, not too big to transport, but big enough to use even in a bit of a chop.
Please let us know if you do decide to go ahead with that idea one day.

Will

88wiI have 2 thay are great have s sailor in one with tiller arm attached the second is nearly finished thay are great fun and look scale would like one 50% bigger may be a winter project

That is a very similar solution to my earlier method suggested Chris, but you have a slot cut into the transom rather than a pair of thin pushrods passing though rubber bellows (or maybe thin “O” rings).

You could make a rubber curtain screen inside the transom (old cycle tube?) with a slit for the arm to slide in to help keep some of the water out, and consider that extra bulkhead to make a sealed chamber as well ?

Much better than sinking.......

Bob.

Cheat, cheat, go and wash your mouth out Bob! I know of course this does happen with fake outboards etc.

But with my Faun I wanted it to be close to scale as possible. The external rudder was fine, my mistake was the positioning of the servo as the rear deck was already in place. I'm not too worried about water penetration as it's only a slow craft and won't be used that much preferring a bit more speed!

Another way to overcome the rudder problem is to cheat 😳

Mount a small conventional rudder post inside the hull as close to the transom as possible with the operating arm inline with the keel so a small operating servo can be mounted beside it.

The brass rudder blade could be remade/replaced to extend back behind the transom and replace the external wooden rudder.

A dummy tiller arm can be attached to it (and still hinged outside the transom) so that when the rudder moved, the tiller arm would move with it.

This is the idea I will try as I like it the best.👍

Bob.

The problem with the Sea Urchin rudder is that it is hinged on the outside of the transom.

The tiller arm would appear to be the obvious way to turn the rudder but connecting it to a servo is a challenge without obvious connection links to it.

Making a dummy sailor with an animated arm holding the tiller arm would probably be best - if you are able to make one.

A push/pull system passing through the transom onto an arm on each side of the rudder would work almost invisibility with a mini waterproof servo mounted inside a small chamber.(an extra bulkhead fitted close to the transom with just enough room for the servo to move freely).

Water leaks would be my concern with this, even with well greased bellows, but the extra sealed chamber just inside the transom (to house the mini- servo) would stop any water leakage penetrating further into the hull - if any should get in.

Not sure why I am so concerned about this, my fast racing hulls all have this system, and I get no leaks .... but the Sea Urchin is so small so the linkages would need to be tiny and maybe harder to seal effectively?

Bob.

Reminds me very much of the Faun I'm building though that has a rounded hull.

The rudder operation is certainly a challenge with models this small and have to admit I rather launched into that on the Faun and it didn't turn out as I really wanted. I should have made the deck at the stern removeable so that I could fit the servo further back, though I don't know if that would have worked or not as the stern is narrow, but you live and learn! I still really like the model though and can't wait to try it on the water.

It's a cute little boat but very nice should look smart when it is done good luck.
Philuk👍

Yes, i know what you mean Bob. It needs to look right, and to work effectively too, but without having too much hardware/linkages/fittings on show.

I have always liked the "look" of the Aerokits Sea Urchin and I actually have a new kit to build one from.

The steering linkage to the rudder is the one area that I need to get "right" in my mind before I start building it!

Bob.