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AeroSouth Sunfish Components

kmisegades

Swamp Goose
Rollaboat Tote sells some fancy pool noodles with velcro straps to potentially help prevent turtling.
Thanks! Seeing this reminds me of one lady Sunfish owner here who strapped a noodle onto the top of her mast.

The aerodynamicist in me cringes at the thought of what the thing does to the airflow, cylinders being about the worst there is when it comes to drag.

..... but I am working on an aerodynamic sleeve that will go over the mast to improve flow. Just for fun.

Our mast float will do a few things in addition to keeping the mast from sinking beyond the surface. Stay tuned.
 

beldar boathead

Well-Known Member
kmisegades said:
I have created a Sunfish Speed Blog at aerosouth.net, citing this thread. Feel free to comment.
Here is the MotionX track of the sail you posted MotionX-GPS Maps | MotionX

If you were in fact trying to get around the course as fast as possible and not just sail around, something looks wrong. When you should be going upwind it looks like you are actually on a close or beam reach back and forth. A Sunfish sails about 45 degrees to the wind with a racing board and sail (that is how I am rigged.) So the angle immediately before to immediately after a tack should be about 90 degrees. In some cases your angle after tacking vs. the prior tack is perhaps 135 degrees and in one case you did almost a 180 and you are almost heading back to where you came from. So either you are not trying to go upwind as fast as you can, or the equipment you are using isn't capable of keeping the boat on the wind as well as a classic setup.
 

kmisegades

Swamp Goose
The wind on our lake varies in direction depending on which branch one approaches or passes. It was also shifting in direction and dropping in strength as we had a front go through yesterday, especially as I came home. It was not a good day for sailing, and was quite cool, but any day sailing is better than one without. The screwy track at the start was the result of my dropping my (really cheap) watch overboard and hoping I could find it. I am still looking for the app that will show my speed along the route overlaid with wind direction.
 

beldar boathead

Well-Known Member
I am still looking for the app that will show my speed along the route overlaid with wind direction.
You would actually need to track the wind direction and speed on the boat. Big boats have have the tech to record windspeed, direction, boat speed, and boat direction, etc, but that is not practical to rig up on a Sunfish. An app would get its wind information (I would think) from sensors somewhere other than your boat, and it will not be representative of what you and your boat experienced.

In general, I don't think that type of tracking is used on sailing dinghies. I know that even Olympic hopefuls are not sailing their Lasers with an onboard anemometer. The best approach for small boats to evaluate and improve boat speed, tuning and overall performance is sailing with another boat. If you can find someone else with a boat identical to yours except for the foils you should be able to learn what you need to. You will want to alternate sailing each boat so you can cancel out the effects of one of you being a better sailor than the other.
 

kmisegades

Swamp Goose
You would actually need to track the wind direction and speed on the boat. Big boats have have the tech to record windspeed, direction, boat speed, and boat direction, etc, but that is not practical to rig up on a Sunfish. An app would get its wind information (I would think) from sensors somewhere other than your boat, and it will not be representative of what you and your boat experienced.

In general, I don't think that type of tracking is used on sailing dinghies. I know that even Olympic hopefuls are not sailing their Lasers with an onboard anemometer. The best approach for small boats to evaluate and improve boat speed, tuning and overall performance is sailing with another boat. If you can find someone else with a boat identical to yours except for the foils you should be able to learn what you need to. You will want to alternate sailing each boat so you can cancel out the effects of one of you being a better sailor than the other.
Good ideas, thanks. Wing design programs are well verified, so I do not doubt the numbers for the current daggerboard and rudder versus my designs. How this relates to actual performance on the water is impossible to say of course. When I was involved (in a very minor way) with the Stars & Stripes 87, we were told they would consider any improvement that individually led to the same effect as not dragging two fingers in the water over the course of an average race. Recreational Sunfish boaters like me will expect a noticeable difference even for an hour on the lake by themselves before wanting to try something new.
 

beldar boathead

Well-Known Member
I looked and saw you are not all that far from Lake Norman north of Charlotte. I believe they sail Sunfish at Lake Norman YC. It would be a good idea to get in touch with them and see if you could drive over with your boat and parts and sail with one of their experienced Sunfish sailors. They could provide some useful advice and perspective while you are in development and before you start production.
 

kmisegades

Swamp Goose
This is true. We have some 30 Sunfish on our lake and regular regattas during the season. The Orient and Harker's Island areas on our coast are popular venues for regattas, including Nationals for several different boat classes.
 

L&VW

Well-Known Member
I looked and saw you are not all that far from Lake Norman north of Charlotte. I believe they sail Sunfish at Lake Norman YC. It would be a good idea to get in touch with them and see if you could drive over with your boat and parts and sail with one of their experienced Sunfish sailors. They could provide some useful advice and perspective while you are in development and before you start production.
Just as an aside, too many reckless speedboats would keep me from sailing a Sunfish on Lake Norman! :eek:
(See link)
 

kmisegades

Swamp Goose
Just as an aside, too many reckless speedboats would keep me from sailing a Sunfish on Lake Norman! :eek:
(See link)
i have heard that in the summer one can walk across the lake from boat to boat. It is near Mooresville, center of the US Motorsports industry. Those guys are into powerboats.
 

kmisegades

Swamp Goose
Just as an aside that was over 16 years ago. It is much safer now and no one has driven a speedboat on the highway in a couple years.
Lake Norman is fairly crowded. Our lake is private and does not allow jet skis. The wake boarding boats though are sometimes a nuisance here, but we all get along fairly well. This time of the year I have the lake to myself.
 

kmisegades

Swamp Goose
An update on the new Sunfish 'Sabre' rudder we're developing at AeroSouth. Below is a picture of our first rough-cut 'Sabre' rudder fin for the Sunfish. Solid poplar is being used only for setting up the 5-axis Homag mill and fixtures. The actual parts will be made from a laminate of Sapele, an incredibly hard and strong variety of mahogany. The fin ( and our similarly-shaped dagger board ) features custom-designed sections and the planform was chosen from 100+ variants. It will fit the existing rudder cheek hardware and will flip up when beaching as for the current fiberglass fins. I hope to have it in the water in a week or so. I considered using glass or graphite, but having a nearby shop with the advanced HOMAG CNC capabilities and the inexpensive Sapele makes wood an attractive alternative to the mess/cost/labor of composites. Our state of North Carolina is a major producer of furniture, so the equipment and expertise is pretty good here.
Sabre_Poplar_First_Roughcut.jpg
 
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