Little Egret: an Egret-style day sailer

[johnno]

Last night I picked up the rudder post from the fabricator. I've decided to make the rudder able to be dropped 4'' so that if I have any trouble with the notorious sharpie rudder, at least I can put it down a bit when there's some water under me. As designed, it is where it should correctly be, with its underside level with the lowest point of the hull. That's pretty shallow, and an extra four inches might come in handy.

I have always assumed that I will insert the rudder after launching from the trailer. When I got the rudderpost home last night, it dawned on me that (especially with the extra 4 inches of length) it was quite long, and I'd have to get into fairly deep water to be able to insert the post upwards from under the hull. I'd say I would need close on a metre of water under the hull. That's a lot to wade out into.

So I've tried sketching the boat on a trailer in photoshop, and taking it through a launch sequence to see if I can leave the rudder permanently in place (though still easily removeable if I wish to work on it). This would be a wonderful bonus. It looks to me that having a boat with such a long stern overhang beyond the aft trailer roller will work to my advantage. The positioning of the bow eye bolt is partly dependent upon the stem thickness, and where I've shown it will help keep the stern out of the water as well. I'm interested in people's thoughts about whether things are likely to work as I've sketched, understanding that these are rough sketches. it looks like I should be well clear of problems of the rudder grounding during a trailer launch. I always launch from a ramp by the way.

[Larks]

Looks ideal John. I launch my Hartley TS16 with the rudder fitted and raised, it sticks out quite a way past the transom when up and it's a drop in rudder so could be easily fitted after launch, but I've never ever had a problem with it getting in the way during launch, so I can't see yours causing any problems at all. The only thing that I do is tie it amidships so that it doesn't get forced around if the boat slides off the trailer quickly on a steep ramp.

[WX]

I like the idea of rig first then launch.

[johnno]

I learn something new everday...now I'm on the straight and narrow

I'll post the detail of the connection to the cb case when I turn her back over.

[PeterSibley]

Interesting John ,I hadn't thought about your rudder setup until now . You're is similar to a boat featured in WB a decade or so ago called GRIMALKIN, a variation of an Egret rather than an Oughtred HAIKU..... but then you're thinking of Great Sandy Strait rather than Moreton Bay .

[johnno]

Yep Peter, this is the trad sharpie rudder set up (pics below), and it ain't efficient, that's for sure. I'm going to use an end plate, and I'm going to angle the top edge back and up at bit to follow the stern wave, and we'll see how it will go. Plus as I said, I'm going to be able to drop the whole kaboodle down 4" if I want while sailing, especially downwind.

It would have been quite easy (and way more sensible) to fit a kick-up type deep foil rudder off the stern, but having got the overhang nice and clear of the water, I didn't want to do that. It is hard to make a kick up rudder the way I'm doing it, though it has been done. Some sharpies used to float a line off the stern down to the end of the rudder to pull it back up if it dropped through, and a similar arrangment could be used to make a haul-up rudder if you could balance it properly I suppose.

[PeterSibley]

A nice NASA foil might help?

[WX]

Wow, your rudder post would want to be strong. As I am sure it is.

[leaotis]

.... I'm interested in people's thoughts about whether things are likely to work as I've sketched,...

Here's my Sharpie's rudder:



And that's the position it's in when I launch. Tiller secured of course.

It's too much effort to push Tempo off the trailer so I let inertia do it.

[johnno]

Thanks Mack, that's really useful! I'd say your rudder is about the same depth as mine, so that's good news. I might just need to practice a bit to get those launches off as smoothly as you can do it..brilliant! Just keep loving that boat too!

[johnno]

Ready for the first coat of white on the topsides tomorrow morning...work on the rudder has begun. I guess she'll look similar for a while as I need a full day between coats. Middle pic is a good test of whether I got the waterline horizontal or not..launch day will be another test

[Larks]

What tha? Is that sunshine up there today?

Maybe you should run a book on the accuracy of the waterline just before the launch.

[johnno]

Sunny Brisbane mate, haven't seen rain here for ages...well, half an hour anyway!

[Duncan Gibbs]

A nice NASA foil might help?

That would be a NACA foil Peter.

http://en.wikipedia.org/wiki/NACA_airfoil

It's the sort of thing that McMullen likes to point out increases lift in the foil thereby counteracting the healing pressure on the sails allowing the vessel to stand up to its rig better. All modern go fast sailing boats have NACA foils for their keels and rudders.

I think the easiest solution would be to lash the tiller to prevent the rudder from swinging around and dinging that lovely teal bottom and launching her slowly. If you can have a long enough draw bar on the trailer and sealed bearings for the wheels then I see no reason why she couldn't just float off the trailer.

[Rik van der Vaart]

Looks real nice Johnno! Looking forward to seeing her in the water.

[johnno]

[QUOTE=Duncan Gibbs;3348094]That would be a NACA foil Peter.

I've done my best to profile the cb to a foil shape though not a true NACA, and I'll have end plates on the rudder, maybe top and bottom...

[RFNK]

Surely a NASA foil would go faster?

Rick

[PeterSibley]

That would be a NACA foil Peter.

http://en.wikipedia.org/wiki/NACA_airfoil

It's the sort of thing that McMullen likes to point out increases lift in the foil thereby counteracting the healing pressure on the sails allowing the vessel to stand up to its rig better. All modern go fast sailing boats have NACA foils for their keels and rudders.

I think the easiest solution would be to lash the tiller to prevent the rudder from swinging around and dinging that lovely teal bottom and launching her slowly. If you can have a long enough draw bar on the trailer and sealed bearings for the wheels then I see no reason why she couldn't just float off the trailer.

Well I knew what I meant !

Thanks Dunc .

[Larks]

Well I knew what I meant !

Thanks Dunc .

We all did Peter, and I reckon I'd prefer a NASA foil as well.

[PeterSibley]

Definitely faster !

[johnno]

First bit of topsides white onboard, and beginning the laminating of the rudder...

Can't do anything else till it all dries, better read my Ann Davison book.....

[johnno]

Still trying to work out the best way to do this rudder. It would be easy except I'd like to be able to dismantle the rudder from the post and tangs relatively easily in case I want to change the rudder design down the track.

The tube is 20mm SS rod and I've had some tangs added. However, they're 20mm apart too, and the rudder is meant to be 24mm. I made it 24mm thick in fact and I've chiselled it back to 20mm thick in one section to get the tangs on.

I have to add a bottom plate too, but I wanted to chisel out that section while I could still lay the rudder flat.

Next I'll make the bottom plate and attach it to the rudder. Then I'll sort out how to bolt? the tangs onto the rudder ...domed bolts with domed nuts or what?

I think I'll fill the recessed section with epoxy filler of some sort. I'd like it to be something I can chip out easily to get the tangs back off the rudder in future. Not sure what's the best filler?

I'll get there....one step at a time.

[PeterSibley]

I'd say a separate but screwed on and bedded piece of ply would be the best way ......

[johnno]

I was thinking the same Peter, but it's only 2mm thick. Hence the idea of some removable filler/fairing. I'll see if anyone knows of some. The other option is to fair those edges so that the water flow is smooth and that might well be the smartest and simplest way to do it.

[PeterSibley]

You can buy HDPE in 2mm, your local plastics shop would give you the bits from their scrap bin ...I've got a pile here too.

[johnno]

You can buy HDPE in 2mm, your local plastics shop would give you the bits from their scrap bin ...I've got a pile here too.

Thanks Peter, that might do the trick. I'll see if I can find some. What would you bed it with?

[PeterSibley]

Actually if there is epoxy under you wouldn't need to bed it ,it would be heavier but the sections aren't big so a bit of stainless would do the job too .

[Larks]

I'd probably go with just some normal epoxy fairing John, get a nice smooth and aerodynamic finish and if you ever need to pull it apart just hit it with a heat gun and scrape it off.

[johnno]

That's a good idea too Greg. I keep forgetting you can reverse-epoxy with the heat gun!

[PeterSibley]

That's a good idea too Greg. I keep forgetting you can reverse-epoxy with the heat gun!

Or smear some wax under the epoxy so it just forms a removable patch then screw it on . Too many bright ideas!

[leaotis]

If not too expensive, I'd buy another length of 20mm SS rod for the new improved rudder. 'Would be cool to compare two different rudders on the same day. And plus have a spare.

[RFNK]

What does the designer suggest?

Rick

[johnno]

What does the designer suggest?

Rick

No precise details. He really suggested to work it through with the stainless fabricator because he knew he'd have ideas too. The way I'm doing it, I'll have a rudder to designed specs with regard to shape and position, but with a different tang set-up, and a variable height rudder post. So all good. I'll probably talk over the fixing of tang to rudder with the fabricator too. The holes are already drilled.

Another rudder is also a good idea if necessary. Pity I can't weld.

[johnno]

Making a little progress, and added another coat on the topsides today. No need for more pics of that!

[P.L.Lenihan]

The painting is certainly bringing out the crisp lines of this design John and your choice of colours very "tropical".Lovely!

If it were I fiddling around with the rudder, I would proceed as follows:

1) Copy precise shape of rudder as drawn by the designer.

2) Secure the rudder post to the rudder as if it had to last a life-time.No fussy-wussy temp stuff.

3) Only use one end plate on the bottom of the blade, as the hull above it will take care of what is rushing off the top of the rudder. Despite the light floating water-line on the drawings, she will probably settle a bit more by the stern once you are on board sitting comfy by the tiller. I know the stern is rather fine and the bottom of the boat will only provide end plate effect within a narrow quadrant but keep in mind that a rudder soon loses its' steering effect and begins acting like a mild brake beyond a certain angle(can't recall the angle). With a split rig like you have, you'll be able to dial in perfect helm balance and literally steer her by sails alone.

4) Sail the blazes out of her,ie;use frequently,discover her foibles and use them to best advantage.

5) Take lots of pictures sailing.

6) Let me buy the first round if we ever meet!



Cheers!


Peter

[johnno]

6) Let me buy the first round if we ever meet! Cheers!

Peter

Thanks for the comments Peter..I was wondering where you'd got to! I figured you've been doing those boatbuilding jobs yuo keep mentioning and couldn't get to the computer.

Okay, it's a deal, you get the first round, but then I get rounds 2-10!

[Duncan Gibbs]

+1 what the tundra dweller said!

[RFNK]

Time it for when I'm up there for fly fishing lessons and I'll hang around up to round 10

By the way, I'd love to help with this rudder but I haven't got the foggiest idea what the rudder is supposed to look like!

Rick

[P.L.Lenihan]

Thanks for the comments Peter..I was wondering where you'd got to! I figured you've been doing those boatbuilding jobs yuo keep mentioning and couldn't get to the computer.

Okay, it's a deal, you get the first round, but then I get rounds 2-10!

It's my crazy work schedule John, 7 on,7 off.....and by gum, I actually began doing some work on the boat yesterday.The first project called: Fixing the terrible finish on the dinette table. Honest!

Rounds 2 to 10? What are ya, a conservative?


Cheers!


Peter

[johnno]

I should make it clear again that Ross has very precise drawings of the rudder itself, albeit with some different sized options. I'm following those precisely. Ross and I have spent countless hours going over and refining the design of the boat and its appertunances and I'm not changing any of those.

It's the mechanics of the fastening of the rudder blade to the rudder post which had some latitude, mainly in order to allow some input from the well-experienced marine fabricator. However, he's off-site and began the rudder tube and post at my request before I had made the rudder, in order that I could fit the rudder tube into the hull at the appropriate time.

In the process the shape of the tangs has changed somewhat, which has made it harder to simply build a rudder and slide the tangs over it. Sliding the tangs over would have made it easy to change the rudder design in future if necessary. It looks as though I'll have to build it as a solid fitting, and more or less destroy the old rudder if I want to change it.

Hopefully that won't be necessary. I think Greg's comment about just epoxy-fairing it in is the best way to go and that's what I've begun. More pics tomorrow.

[RFNK]

What sort of work Peter? A schedule like that here would most likely be work in mining or an oil rig.

Rick

[johnno]

I actually began doing some work on the boat yesterday.The first project called: Fixing the terrible finish on the dinette table. Honest!
Cheers!
Peter

If there are no pics, it didn't happen Mr Lenihan sir!!!!

[P.L.Lenihan]

+1 what the tundra dweller said!

Considering what I've been hearing about the endless rains where you are Mr.Gibbs, should I forthwith begin calling you swamp dweller and enquiring about the fleshy bits sprouting between your toes and fingers? Of course not! You are just gnashing your teef for lacking the required stamina to regale in real full four-season-in-your-face climate! Up here on the frozen wastelands, we of the North use a term for folks like yourself and although I may get banded for using such foul and dastardly word, rest assured I do it only as a public service and wish to remind you I did not invent this word. Are you comfortably seated Mr.Gibbs? Beverage in hand? Good. Well here is what we of the North call you of the South: wimp!


Cheers!


Peter

[RFNK]

I probably still don't get it but couldn't you make a tang shaped a little like the fork of a gaff or bicycle forks to go into slots shaped into the rudder? The post could be threaded so the tang just gets screwed on or is held by a nut. If you cut the bits out of SS, it wouldn't cost much to have it welded together. Alternatively, you could make a model from ply and just get the metal shop to make it.

Rick

[PeterSibley]

There are lots of ways! I prefer a custom casting in a rare metal with acid etched scenes of frolicking fishes .... I mean if it's going to be done do it right ... perhaps a bit of silver inlayed into something yellow, it would add a certain flare .....

[RFNK]

Sibley's been dropping acid again

Rick

[P.L.Lenihan]

If there are no pics, it didn't happen Mr Lenihan sir!!!!

I hear you John...but it is a work just begun after a considerable hiatus that I would like to have pictures of the start,middle and end to the project before actually posting.Otherwise, one picture alone will only serve as a cruel tease.........



Cheers!


Peter

[johnno]

There are lots of ways! I prefer a custom casting in a rare metal with acid etched scenes of frolicking fishes .... I mean if it's going to be done do it right ... perhaps a bit of silver inlayed into something yellow, it would add a certain flare .....

And yes Rick, you're right, but that's not what the fabricator ended up telling me I needed so I went with what he said. Now he's made it and I'm just trying to come to grips with what he's made. I could get him to do another but she'll be right....I think

[johnno]

one picture alone will only serve as a cruel tease.........
Cheers!

Peter

Oh, we're very partial to teases, we married men.....

[PeterSibley]

Sibley's been dropping acid again

Rick

No respect for the trades by gum!