High Performance MPX Foil/Self-righting Trimaran-The Test Model

For those keeping track here is the situation with the boat testing as of now.
Hope to get the next (long) video Sunday 9/14/14. Problem is we only have 8-11 Sunday morning(including getting there and back) and there is not likely to be wind. But soon the cold fronts will give plenty of wind-ideal for the reefed rig and finding smooth water for the first time with a good wind. The reefed rig is probably good up to 15 + esp. w/o the jib.

Testing Status

It's interesting to note that this boat has been sailed a total of 1hr 50min with a total of 26 minutes and 38 seconds of sailing video uploaded to YouTube.
In that very short period of time, a radical foiler design using two different foil systems in a combination never before seen in the history of mankind was taken from light air testing to full flying foiling. This is a sort of Index so that if the reader is interested in reading about development milestones they can do so easily from this page:
Sailing History--( youtube channel: https://www.youtube.com/channel/UC6S7JPG1d2uZ91lqt7ObyIw )

1) First Sail-6/17/14, page 91, post 1356. Total video time: 10:55. Total estimated sailing time:25 minutes.
video- https://www.youtube.com/watch?v=X0AHD34_-8c
video- https://www.youtube.com/watch?v=74KEpcmgCh8
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2) Second Sail/ Foil Assist-6/26/14,page 93, post 1393. Total video time 4:42. Total estimated sailing time: 20 minutes.
video- https://www.youtube.com/watch?v=FF7cy8AoFnU
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3) Third Sail-7/10/14, page 102, post 1522. Total video time:2:58. Total estimated sailing time:30 minutes.
video- https://www.youtube.com/watch?v=LmXCdAlo4mk
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4) Fourth Sail/ Full Flying Foiling-7/24/14, page 106, post 1589. Total video time: 7:48. Total estimated sailing time: 35 minutes.
video(long version)- https://www.youtube.com/watch?v=4YBOEolFqiE
video(short version)- https://www.youtube.com/watch?v=7Mok3d4KiMI


Longest period of foiling=15 seconds-reason: Land
The boat would foil for hours in 5mph of wind or more if radio range wasn't a concern and if land didn't get it the way. She was rock steady in pitch and tended to roll a bit in waves always maintaining full foiling.
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Milestones of Development: (click on page above)

1) Reefing, page 102, post 1527
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2) Ama foil mods, page 104, post 1554,
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3) i-flap description, page 105, post 1561,
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4) Pictures of ama, main and rudder foil mods, page 105, post 1575
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5) Pictures of painted foils, page 106, post 1578,
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6) Summary of changes/fixes before first full flying video,page 106, post 1581,
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7) Changes made since first full foiling video, page 109, post 1626,also see page 111, posts 1659, 1661 and 1662,
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8) Removal of i-flap on port foil, page 109, post 1628 and 1630,
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9) GCD and Reefing, page 109, post 1631,
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10) Cutting mast for reefing, page 109, posts 1633-34,
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11) Updated Specifications, page 110, post 1639,
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12) Pictures of reefed rig, page 110, post 1642
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Next-God willing and the creek don't rise a knockout all foiling video......

Pictures: the boat and Coach Dan Burkes Pirates Team logo and now the Fire Arrow good luck charm:

 

Fire Arrow Foiler / MPX Foil System Testing and Development

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I think that's a good observation. How's your boat coming, Curtis?

 

Fire Arrow Foiler / MPX Foil System Testing and Development

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Well, we've had a hard time finding the ideal conditions for early testing(after the initial light air tests): wind with no waves. But that's about to change as the wind switches from SSE to north for much of the next few months. Can't wait to sail with the reefed rig!
Dan and I have a narrow window Sunday-8-to 11 from leaving here to getting back. Today was the first morning in two or three weeks there was wind-and its perfect from the North due to a weak cold front. Maybe it will hold thru the weekend.....

 

Fire Arrow Foiler / MPX Foil System Testing and Development

For those interested in understanding more about UptiP foils with special emphasis on the C Class ,there is a great article in Professional Boatbuilder, Number 151, October/November 2014 by Steve Killing, the designer for the Canadian Little America's Cup Team, pages 110 to 118.
He mentions the breaching of the inboard tip shown in one of the pictures below:
"Breaching. Sometimes the leeway effect* will be enough to bring the boat back down to a reasonable ride height, but if acceleration is great enough, as is the case with a windward mark bear-away, another safety valve is required. When the tip of the foil breaches the water's surface, a further loss in lift is usually enough to counteract the upward inertia and to gently bring the boat back down toward the quasi-stable condition."

*Steve Killing on leeway effect:
"The higher boat speed creates more lift from the tip, and the hull begins to rise, leaving less daggerboard shaft in the water. With a reduction in daggerboard shaft area, the boat makes more leeway and this added leeway is the key to the dynamic stability of the canted "L" foil." (Called an uptip foil by the team that invented it-DL)
He goes on to use words to the effect that the high pressure impingement(from leeway) on the top of the UptiP portion of the foil "reduces the magnitude of the lift vector" slowing the rise of the boat. The stages in the operation of an UptiP foil can be seen in the Fire Arrow pictures below.
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The fact that the Fire Arrow ama UptiP foils worked so well in the very first foiling video is one of the biggest and most rewarding successes of that day!

Pictures-L to R, 1) ama foil at steady state as shown in A & B in two different speed and load conditions, 2) #2 and # 5 illustrate the breaching of the tip as a backup altitude control in times of acceleration:
click--

 

Fire Arrow Foiler / MPX Foil System Testing and Development

Hopefully, we'll be able to sail Sunday-if not then the following Sunday and so on until we get the next long video!
Here is a list of the modifications made since the First Foiling video on July 24th,2014. I've included page and post references:
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1) Changed the wand tension system to allow maximum force on the wand when it is down(flap generating downforce).-page 111, post 1662
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2) Painted small black section on hull immediately behind each wand(as viewed from the side) to help the white wand to show up better in the video.
-page 111, post 1661.
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3) 5 full length battens added to main,GCD removed and mast extention added, peak halyard and downhaul purchase increased. -page 109,posts 1631 and 1632.
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4) A reefing system is now incorporated in the rig with a removable mast section and velcro fasteners to hold the rolled up main.-page 109, post 1633-1634 and page 110, post 1642.
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5) i-Flap removed from port foil(still on stb foil) to see if I missed a step in ama foil development by not trying more area before I tried the i-Flap. The resulting foil has the same planform area as the foil with the i-Flap and a few degrees of washin towards the tip. -page 108,posts 1617 and 1618 and page 109 posts 1626 and 1630. Once I have these results I'll either add the i-Flap back to the port foil or remove it from the starboard foil. Then the process of changing the foil angle of incidence,first, and second changing foil area can start-modifying one foil at a time. The focus will be in reducing drag as much as possible within the constraint of light air takeoff which is the main focus of the Fire Arrow project.
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6) Considered adding aero drag reduction measures to the crossarms but postponed that due to a suggestion from Steve Clark,-page111, post 1653.
(While I greatly appreciate Steve's suggestion regarding aero improvements, I disagree with his assessment of the level of success achieved by the Fire Arrow in her first foiling video. My response to that: -page 116, post 1740)
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7) Added experimental endplates to the outboard ends of the partial span mainfoil flap. -page 112, posts 1667 and 1668.
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8) Added mount for a Velocitek Speed Puck to use to calibrate the i-GOTU* GPS tracker used since day one. -page 112, post 1670.
* see picture of the tracker and its installation on the boat page 113, post 1682.
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So the major experiment for the next test sail is the port ama foil with the i-Flap removed compared to the starboard ama foil still using the i-Flap.

 

Fire Arrow Foiler / MPX Foil System Testing and Development

No sailing today or for weeks or months. I hurt my hip a few weeks ago and it is extraordinarily painful when I carry stuff or twist the wrong way. Impossible to load the car and/or assemble the boat.
Perfect wind this morning.......

 

RC Foiler Development

This is from the German RC forum about the development and first sail on foils of a French 2 meter tri using surface piercing foils.
Here is the same boat with initial tow tests. The tow line was fastened to the forward crossarm instead of to the CE using a mast stub: https://www.youtube.com/watch?v=_Dpi-RZNdoE#t=12

https://www.youtube.com/watch?v=FSluJCMUMoY#t=64

 

Testing and Development

For those interested in how to set a model sailing multihull up for tow testing watch this video from 22:50 in to 23:55 :
https://www.youtube.com/watch?v=XQoNYe2jFP8#t=4791

 

Fire Arrow Foiler / MPX Foil System Testing and Development

Have any of you guys used linear servos like Firgelli or any other brands? I may need a 1.25" travel at 2 seconds(max)proportional linear servo compatible with normal RC receivers. Preferably 6v.

 

Fire Arrow Foiler / MPX Foil System Testing and Development

This is the system I'm going to get for this boat at my earliest opportunity. It's video goggles supplied with a video transmitter, receiver and color camera for $279. Back in 1985 when I was developing a VPH(video piloted helicopter) we paid $20,000 for a video transmitter and receiver and $2500 for a color camera!

This is flat amazing: http://www.hobbyking.com/hobbyking/...5_8G_TX.html?gclid=CI3SnY7968ACFQQT7AodK2cASg

click-

 

Do you mean goggles?

 

You see its like this: I had to google the goggles ......(thanks)

 

D4Z AC 62 RC Prototype

I designed and built this 51.5 X 33"X 4lb cat 15 years ago(with "normal" bows) and in the last couple of days I've brought the design fast forward by changing the bows-and as I have time I will make foils for it-UptiP main foils(based on the Fire Arrow foils but smaller chord and symmetrical) and "L" or t-foil rudders. I proposed a new class on an RC Forum- an "AC 62"-a more or less scale version of the new AC boats with one design wing rigs(or soft rigs-skippers choice). My part will be to eventually convert this model-originally called D4Z-to a test model prototype for the new proposed class. I'm going to experiment with foils and try to develop a relatively simple foil system loosely based on the full size foils.
This allowed me to work off a little of my frustration.......

Left, original bow:

 

Fire Arrow Foiler / MPX Foil System Testing and Development

Mr. Watson is looking for help in data acquisition for a scale model boat both sail and power. If you have any ideas here is a link to his thread:
http://www.boatdesign.net/forums/on...data-acquisition-thread-51395.html#post705743

 

Thanks for the promo Doug - this is a very fascinating but long thread to peruse.

I will power through it to get inspiration and knowledge,

The gear thats available these days is astounding.



edit: hey Doug - this Foil thing is catching