Center board and rudder

Well, I had hoped the wind would be less than this! Here is the traveler setup. Red and orange are test equipment colors. As soon as the wind becomes more of a breeze I’ll go try it out.
Main first, then full sail.

 

Well,
Forecast this morning was 5 knots, I think I powered out in 8 to 10 Kts. I had the main reefed (no jib). The boat would NOT stay in irons for me to hoist the main. With 10 knots it was determined to run with the wind!
I had to stop my test run to attempt another with “breeze conditions.
Call me crazy, but a dinghy should be good to go in 10kts of wind!?
I’m used to running out in 15-20 with fresh white caps for a good day!!!
I had the traveler centered but never got the chance to raise the sail and experiment.
Pig pig pig

 

A couple of thoughts;the daggerboard is clearly too small and we would probably benefit from a good pic of the boat from the side with the full rig in use.A new two inch thick daggerboard seems much too thick for a comparatively small boat,I would expect no more than about 1 1/4" to be in the "normal" range and for experimental purposes I would suggest an experiment with a rough and ready version to fit in the existing case-just don't use plywood because sooner or later they always break across the grain at the keel line.The current one hasn't because it doesn't generate sufficient force.I would suggest a chord of about 3/4" less than the fore and aft dimension of the case and some attempt at taking the square corners off below the keel.A taper on the trailing edge perhaps 3" in and down to about 1/4" width at the aft edge (with the corners softened) and an entry of say 1 1/2" to a curved leading edge would be a good initial effort.

The mast rake and indeed the control of the mast might need looking at hence the request for a pic of the boat rigged and under sail.In the first post,which seems a long time ago now,it appears that the mast is not constrained at the deck level.This would be unusual and potentially unhelpful,most open boats have the mast pass through a thwart and most decked boats have packers or wedges to prevent excessive bend.There is no doubt the boat can be made to sail better and there is an amount of eagerness to see it happen from those of us following this thread.

It is a pretty boat and I have to wonder why anybody decided an inboard rudder was a good idea on such a small vessel.While it isn't hugely relevant to the issue you would get more efficient steering by switching to a transom hung rudder and you could have a lifting blade so that creeping into the shallows remained a possibility.I'm reasonably sure that the "old wood" inside the boat is a mast step for the tenon on the heel of a mast-quite possibly not the current mast.That makes me wonder if the mast was moved to allow space for the daggerboard to operate.I would say you definitely need a new board and for test purposes more or less anything laminated from softwood from the big box outlets will be an improvement on what is there at the moment.

 

A new board is on the list for sure. If I need to move the trunk I would like to make a 18 inch wide center board. That will keep the draft a foot shallower than the 12 inch width now. (Based on a 4% dagger board area to sail plan area.) 2 inch thick matches the NACA profile.
The rudder does kick up! But, to make it better I need to replace the solid bar with tubing so I can rig up and down lines through it.
Pig

 

You've lost me there.I completely fail to understand what relevance the thickness of the board has to the sail area.I don't see why you can't use a section with a thickness to match the existing slot and for the time being a chord that matches it too.There ought to be a symmetrical NACA section to suit the dimensions and it will be a huge improvement over the undersized piece of ply that is currently in use.

 

Wet Feet,
Sorry about that. The current board is solid wood and it would have been better if they just made a straight leading and trailing edge profile from it. Unfortunately the trunk is made to fit the big box store’s idea of 3/4 of an inch. The a lot is only 5/8 of an inch at its max and the board is 9/16 thick.
I’d like to make a board with a layup cross section like this

it would require a 2 inch wide slot with an 18 inch chord and a wetted length of 32 inches for a total area of 4sq ft.
This would also keep the length manageable inside the dinghy for deployment and adjustments.
Now this is not a racing boat. I’m looking for mild sailing manners and I realize increasing the chord reduces the draft but also induces more drag. I’m also up to the idea of using the 2 inch area to install some weight.
Right now, to save some money and time, I’m focused on the mast foot location and sail placement to relieve the Lee helm problem. The boat tracks “alright” with the current board and I can run my experiments. Fabrication is my next project.
Pig

 

That makes it clearer but it still seems like a very fat section to me.I have a chord of about 18 inches and a thickness of one inch using a NACA 63006 section.A 5/8 slot is a bit skinny,but widening it might be an adventure.With all that thickness you may not need those graphite strips.

 

Thanks! I’ll look up that 63006. Also, there seams to be added layers of fiberglass bringing in the slot to 5/8. I think a heat gun and some tools could remove it and it would still be 1/2 inch of glass and metal there!
Pig

 

Well everyone; it’s been one of “those” years. I have finally found some time to daydream and look at this boat again.
I found several articles about mellonseeds being built with dagger boards and later swapped for center boards. That sounds like an option and a happier way to sail in shallow waters. I have sand mounds here, not bars. A happy 3.5 ft water instantly becomes a foot or less with no tell from the wind or waves. It is difficult to pull out a dagger board after you’ve run aground. A kick up option would be nice.
hopefully the weather will let me move ahead with my plan to move the mast step back. When i balance out the sail plan that will give me an idea of space to work on the center board.