Dream Flyer fl-an 18' daysailing trimaran

Dream Flyer fl

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The DSSM foils are placed where they will generate vertical lift substantially forward of the static center of buoyancy. This will counter the pitching force of the rig in conjunction with crew movement fore and aft. It is critical that the main hull, with fore and aft crew movement, control the pitch so that the DSSM foils never go negative. The DSSM foils are using a section developed by Hugh Welbourn for DSS and are mounted at zero degrees angle of incidence relative to the ama and at +1 degrees relative to the static waterline of the main hull. The section lifts below zero degrees.
So, the dynamic relationship between the mainhull planing center of lift, the ama foil center of lift and the CG of the crew weight is critical for pitch control. A rudder t-foil, that I already have, can be added if required for better control.

 

If the location of the foil was limited to the static center of buoyancy as on a shunting proa , would it still be possible for the main hull given sufficient length to provide adequate pitch control if the center of gravity could be moved aft. I apologize for being of topic but I am about to start testing a scale model proa that is tentatively to have a lifting foil to leeward and any incite that you may offer would be greatly appreciated.

 

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Timothy, on a shunting proa you'd probably have to use an ogival section so it works in both directions. Check out Tom Speers site for proa foils.
Depending on the amount of SA, crew movement may be ok for pitch control.
Good luck with your model tests. You might check out the SRT(Self Righting Trimaran) Test Model thread for more info in setting up for testing a model.
http://www.boatdesign.net/forums/mu...-self-righting-trimaran-test-model-36058.html

 

Dream Flyer fl

--Ordered a Velocitec Speed Puck GPS speedometer today-essential for seeing what this boat can do: http://www.velocitek.com/speedpuck/features/

--Also ordered two high back bucket seats from Aircraft Spruce: http://www.aircraftspruce.com/catalog/appages/bucketseats.php They will be mounted facing inboard on each side of the main hull on two carbon tubes which will also act as rails allowing the seats to slide fore and aft. Each seat weighs a bit over 3lbs. I may do surgery to them to allow sumptuous foam "upholstery" for my posterior largitis.

--Ordered the "Go Pro" Outdoor version waterproof video camera to document whats going to be happening: http://gopro.com/cameras/hd-hero2-outdoor-edition/
It will be mounted on the boat to look at one foil, to look at the boat from an ama and at the boat from aft of the main hull-good stuff to come!

 

Dream Flyer fl

The seats came yesterday. For some reason ,they seem a little big for the boat:

click on image--

 

Cant wait to see it sailing Doug !

 

+1

Cheers!!!

 

Just curious Doug, just curious: Of course you thought of fixed winging the boat, how about that??

 

Dream Flyer fl

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Actually only in the far reaches of my mind-and then only briefly. More than anything I want to get a rig on the boat that I can test the "MPX" system with: bi-foil on the main hull and DSSM or curved foil on the ama. Wing rig probably not.....Also want to experiment with planing amas....So much to do so little time....

 

Dream Flyer fl

The styro lady is ready to go-about two days once I give her the go-ahead.
Don't want to have the amas cut out and laying around for a few weeks because until they're carbonated they will be fragile. Sharon will deliver them to Falcon Marine when everthying else is ready. Carbon tubes are being built by Forte now and Rick Loheed is doing the foils momentarily. When everything is here Matt will begin. Estimate 2-3 weeks from now before he gets the stuff. No idea how long he will take but probably not very long.

Picture: 16 knots already! (go pro camera and Velocitek speed puck arrived Tuesday!)--
click on image-

 

Dream Flyer fl-hurry up and wait

Waiting for hydrofoils and carbon tubes-at least two more weeks. When they get here the amas will be done within three days and then Falcon Marine will have everything they need.
Below are the hinges and latches: the hinges have a 3/8" stainless steel pin and the latches-sort of miniature hyfield levers- have adjustable tension. The latches are being used at Eric Sponbergs suggestion and the hinges are also fairly beefy at his suggestion. Hinges on top of the carbon tube, latches on the bottom. The tubes are joined with a sliding snug fitting carbon ferrule that slides out of the way to allow folding.

click on image-last image shows a rough illustration of the sliding insert and hinge and latch position:

 

Dream Flyer 18 fl

Remember the story of Joe **** building a boat in his garage and not being able to get it out? Hah! Well, the way it looks now when the 1.75-2' is added to the main hull I may not be able to get it in! Looks like I may have to remove the rudder each time at a minimum and thats a pain......Working on it while I wait....
Another thing: a few years ago I designed a kick up rudder with a t-foil on it and had the "key" to the system machined. The foil is mounted to this machined part and glued into the rudder foil. The rudder was custom made by Dotan( http://www.dotan.com/ ) and is a pretty neat arrangement-you use the tiller to kick up the blade. Take a look at their site...... When they made it, they molded in a tube for the control rod for the blade that allows the t-foil to neutralize as the rudder blade kicks up. I'm thinking I will use it after initially sailing without it, both to test the system and see what improvement the t-foil may offer. I didn't use it on the original foiler because, in tests, there was a remote chance(I thought) that the foil drag might cause the rudder to kick up. This version would have a much smaller t-foil and might just work.

Amazing find: very similar idea to mine(in concept only-not in the way its done) using a Dotan rudder- http://www.catsailor.com/forums/ubbthreads.php?ubb=showflat&Number=106516

Pictures: Dotan Rudder. #2 shows the removable tip. The "mount" for the hydrofoil fits in here and the foil automatically neutralizes as the rudder kicks up. If it works well, and is not too expensive, it will allow kick-up rudders with t-foils instead of cassette(daggerboard type) rudders on some designs.

click on image-

 

Dream Flyer 18 fl

Well, I solved the length problem getting the boat in the garage with a small modification to the trailer,so thats ok. In the process I found that my folding system(which I thought was pretty cool) will not work in terms of allowing the boat to be stored in the garage. Damn! Folded it's about 8" too high to go thru the mini garage door. So, I'm going with the Weta style "plug-in" system which will be much lower but require slightly more work to set up.
Still waiting.....

 

Keep on plugging through the details. Regardless of what does not work, there is value to finding out the things that do.

 

Dream Flyer fl

Thanks, PF. The unfortunate thing about the folding system is that it really wasn't that it wouldn't work-it was that after it folded it wouldn't fit in the garage! Better now than later. But I'm disappointed because it is a neat little system......