Thursday, November 5, 2009

Decisions, Decisions!

Ok, so if you've never built a project from scratch with no instructions at all, there's something you should know. One spends a ton of time just staring at the project trying to figure what to do next and how to do it. Sometimes I'll just stare for 20 minutes or more running dozens of senarios through my head. Trying to figure loads, strength, asthetics, all these variables. My latest problem I'm contemplating is the rudder. Transom hung? OR mounted under the hull. If I go with a rudder hung off the transom, it will be a cassette type so I can easily pull it up for trailoring, or cleaning off sea grass. The negative is that the transom has this sweet slope to it and I'd have to build out some sort of structure to mount the rudder on. I'm afraid this would clutter the look of the boats rear end. If I go with a rudder mounted under the hull, the back of the boat stays clean, and I can mount the outboard bracket in the center. I think this will look nicer. The problem with this is it will be tougher to remove the rudder for trailoring. (Someone will have to either get wet, or we need to use the lift) Does anyone have any input on this? The good thing is that whatever I choose, it wouldn't be hard to change over to something different later on. Just wondering what other people think.

7 comments:

Anonymous said...

i think the transom would seem pretty cluttered with both a motor and a rudder, but i dont really know the scale of the boat.

-stu (rock lobster!)

Anonymous said...

i cant edit that post, but you should think about how often you plan on trailering it, if your gonna leave it in the water like the juan then i would definitely mount it under.

Anonymous said...

my brain wont stop, so i cant sleep. what if you added a round metal rod to the top of your rudder with cassette mounts on it that is long enough to get the rudder below the bottom of the boat and a slot in the deck (think keel box) that the rudder could slip through, that had the cassette brackets mounted on the forward inside wall, it would let you pull the rudder easily and solve both problems, you could even make a flush mount plug that would lower the drag from the hole in the boat if you wanted. im sure there is some sort of flaw in my plan but i dont see it quite yet.

hope that made sense.

stu.. again!

Anonymous said...

Ding, ding, ding! We have a winner. I like Stu's idea of the cassette. I had given it a bit of thought but had rejected it because the slope of the transom and where the rudder will mount under the hull would require a really long slot box to slide it into and get the rudder shaft into position. But after Stu's mentioning it again, I thought about it, and I think it could work. I think I could build the slot box on an angle. The rudder could then slide down on the angle and then rock back into position. I'm going out to stare at it again. Thanks Stu!

Anonymous said...

Ok, just went out and looked. The sloped slot will work. I will make the cassette that the rudder post passes through triangle shaped. That way, once the ruder slides through the slot and gets below the hull, it can tilt back into position--with the sloped part of the triangle cassette against the sloped transom (now the rudder post is vertical). Then I lock it in position with a triangle shaped plug that slips in just forward of the rudder post.

Also by being at the very back of the hull, the slot should be mostly just above the water line--so drag shouldn't be a huge factor. I agree with everyone that the rudder below the hull will look cleaner. I think the weight will not be much more than a cassette system hung off the back. Plus the weight won't be so far aft. The slot will also provide some additional structure to the cockpit floor. And Luke won't have to swim to get the rudder on and off each time!

I've got to go fly for a few nights now so I'll have some time to tweek this idea. Thanks guys!

-SB

Anonymous said...

More thinking--I'm going to move the rudder forward 11 inches. That way I don't have to slide it in at an angle and make a two part cassette. Just a slot through the deck and hull, with a cassette that fits in the slot, with a rudder post running through it. --pretty much like Stu said. Also when moved ahead, the top of the rudder will be below the water line (in theory) This will minumize spanwise water flow over the rudder as the hull will act as sort of a cap. It's a win/win....I think.

Scottie said...

Shannon, I would really take a hard look at the Hendo 30 and M32 rudder set-up. It is a turret casset mounted inboard. The turret is a large bearing in the floor and the foil just slides up and down like a casset. Might solve your problem, plus the rudder will be less likely to ventilate since you'll have the hull acting as an end plate helping to control end losses.

-Scott