Boat Design Forums  |  Boat Design Directory  |  Boat Design Gallery  |  Boat Design Book Store  |  Thanks to Our Site Sponsors
  #1  
Old 05-16-2016, 06:20 AM
Manfred.pech Manfred.pech is online now
Senior Member
 
Join Date: Apr 2010
Rep: 319 Posts: 493
Location: EU
Foil Optimist

Optifoil:

http://www.ouest-france.fr/bretagne/...timist-4166838

https://www.facebook.com/media/set/?...7640314&type=3

http://atoutnautic.fr/info_detail.php?article=1279

http://segelreporter.com/regatta/jug...en-optimisten/

Acrobats needed.
Reply With Quote
  #2  
Old 05-16-2016, 07:54 AM
Doug Lord's Avatar
Doug Lord Doug Lord is offline
Flight Ready
 
Join Date: May 2009
Rep: 1362 Posts: 13,712
Location: Cocoa Beach, Florida
Foiling Optimist

Thanks, Manfred! One of your links showed the (almost) foiling Opti put together a few years ago by Adam May, a well known Moth sailor. They used a wand for altitude control but apparently this new boat relies on crew movement? Works on kitefoilers and foiling windsurfers-may work here....
No foiling pix that I could find.....
__________________
yes, it is a Revolution
WOLF-daughter of fire arrow
Reply With Quote
  #3  
Old 05-16-2016, 09:51 AM
Manfred.pech Manfred.pech is online now
Senior Member
 
Join Date: Apr 2010
Rep: 319 Posts: 493
Location: EU
Quote:
Originally Posted by Doug Lord View Post
Thanks, Manfred! One of your links showed the (almost) foiling Opti put together a few years ago by Adam May, a well known Moth sailor. They used a wand for altitude control but apparently this new boat relies on crew movement? Works on kitefoilers and foiling windsurfers-may work here....
No foiling pix that I could find.....
Do you think it is possible to balance it ?
Reply With Quote
  #4  
Old 05-16-2016, 10:01 AM
Doug Lord's Avatar
Doug Lord Doug Lord is offline
Flight Ready
 
Join Date: May 2009
Rep: 1362 Posts: 13,712
Location: Cocoa Beach, Florida
Foiling Optimist

Yes! The people who foil kiteboards control altitude with balance. I think a wand system might be easier but I imagine if you learn to balance the thing it will become second nature.
__________________
yes, it is a Revolution
WOLF-daughter of fire arrow
Reply With Quote
  #5  
Old 05-16-2016, 03:53 PM
Skyak Skyak is offline
Senior Member
 
Join Date: Jul 2012
Rep: 152 Posts: 1,143
Location: United States
Quote:
Originally Posted by Manfred.pech View Post
Do you think it is possible to balance it ?
No.

They would need much more freedom to move. Kites and windsurfers have the full length of their legs to move in 3D and the sail can move in 3D independently of the hull which they brace with. This opti sailor has a hard time even moving in 2D and the sail has only rotation which will not do much downwind. The kicker is that the rudder is too short -the main foil will still be lifting when the rudder comes out of the water. The loss of lift aft will increase the angle of attack to stall or more likely pop out of the water and come crashing back down.
Reply With Quote
  #6  
Old 05-16-2016, 04:44 PM
Doug Lord's Avatar
Doug Lord Doug Lord is offline
Flight Ready
 
Join Date: May 2009
Rep: 1362 Posts: 13,712
Location: Cocoa Beach, Florida
Opti Foiler

On almost all foilers with fully submerged foils the rudder foil is closer to the surface static, but as the boat pitches up the rudder foil moves down relative to the main foil. It's important to have the rudder higher than the main foil or the wake of the main foil will screw up the rudder foil.
I like the way they increased the distance between the main foil and rudder foil-effectively increasing the "footprint" of the foil system w/o using a gantry like on a Moth. The F&A separation of the foils(far larger than on a kiteboard foil system) will be a big asset and would tend to help make it possible to balance with just weight movement.
These guys seem to be pretty experienced boat builders and probably know what they're doing. I'd imagine a kid could stand up in the thing if needed to improve balance....
I still think a wand system would be better but if they can balance it w/o too much hassle then you can't get much simpler.
__________________
yes, it is a Revolution
WOLF-daughter of fire arrow
Reply With Quote
  #7  
Old 05-16-2016, 05:05 PM
Skyak Skyak is offline
Senior Member
 
Join Date: Jul 2012
Rep: 152 Posts: 1,143
Location: United States
Quote:
Originally Posted by Doug Lord View Post
On almost all foilers with fully submerged foils the rudder foil is closer to the surface static, but as the boat pitches up the rudder foil moves down relative to the main foil. It's important to have the rudder higher than the main foil or the wake of the main foil will screw up the rudder foil.
I like the way they increased the distance between the main foil and rudder foil-effectively increasing the "footprint" of the foil system w/o using a gantry like on a Moth. The F&A separation of the foils(far larger than on a kiteboard foil system) will be a big asset and would tend to help make it possible to balance with just weight movement.
These guys seem to be pretty experienced boat builders and probably know what they're doing. I'd imagine a kid could stand up in the thing if needed to improve balance....
I still think a wand system would be better but if they can balance it w/o too much hassle then you can't get much simpler.

I would predict this 1.0 version will be way too difficult to sustain foiling. That rudder is way too short. A wand and flap is what they need but it's pretty much a do-over. The foils are so big they might have been able to do something like a V to control height -no moving parts, simple build.

It might be possible to use the surface proximity to help control height but that is more like planing than real foiling.
Reply With Quote
  #8  
Old 05-17-2016, 12:07 AM
SukiSolo SukiSolo is offline
Senior Member
 
Join Date: Dec 2012
Rep: 271 Posts: 1,268
Location: Hampshire UK
It's amazing how fast the 7 year olds will pick up foiling....
Reply With Quote
  #9  
Old 05-17-2016, 02:37 AM
Manfred.pech Manfred.pech is online now
Senior Member
 
Join Date: Apr 2010
Rep: 319 Posts: 493
Location: EU
I think there are a lot of examples to lern from. But all sailors I've spoken with pointed out the difficulty to foil the foiler in reality. Something for artists?



http://www.teknologika.com/mothblog/...in-hydrofoils/

http://images.google.de/imgres?imgur...RLBNUQ9QEIJzAE
Reply With Quote
  #10  
Old 05-17-2016, 12:47 PM
Jamie Kennedy Jamie Kennedy is offline
Senior Member
 
Join Date: Jun 2015
Rep: 117 Posts: 541
Location: Saint John New Brunswick
Looks pretty good.
I might tweak a few sail ties a mm or two. ;-)
Reply With Quote
  #11  
Old 05-17-2016, 09:12 PM
portacruise portacruise is offline
Senior Member
 
Join Date: Jun 2009
Rep: 218 Posts: 982
Location: USA
Thanks for pics of a nice set up.

Anyone seen a setup where the foil can be retracted, so the boat can be used efficiently when conditions are hampered by the foil? Examples like low draft, launch/retrival, debris, insufficient wind/power, etc.

PC
Reply With Quote
  #12  
Old 05-18-2016, 02:07 AM
Tiny Turnip Tiny Turnip is offline
Senior Member
 
Join Date: Mar 2008
Rep: 743 Posts: 472
Location: Huddersfield, UK
Quote:
Originally Posted by Manfred.pech View Post
I think there are a lot of examples to lern from. But all sailors I've spoken with pointed out the difficulty to foil the foiler in reality. Something for artists?



http://www.teknologika.com/mothblog/...in-hydrofoils/

http://images.google.de/imgres?imgur...RLBNUQ9QEIJzAE

'Note: Rigging omitted for clarity.' Ain't that the truth:

Reply With Quote
  #13  
Old 05-18-2016, 02:10 AM
Tiny Turnip Tiny Turnip is offline
Senior Member
 
Join Date: Mar 2008
Rep: 743 Posts: 472
Location: Huddersfield, UK


Top two comments made me giggle.
Reply With Quote
  #14  
Old 05-18-2016, 06:38 AM
Manfred.pech Manfred.pech is online now
Senior Member
 
Join Date: Apr 2010
Rep: 319 Posts: 493
Location: EU
Here is the wing for the thing:

Reply With Quote


  #15  
Old 05-18-2016, 04:39 PM
CT249 CT249 is online now
Senior Member
 
Join Date: May 2003
Rep: 215 Posts: 841
Location: Sydney Australia
Quote:
Originally Posted by Manfred.pech View Post
I think there are a lot of examples to lern from. But all sailors I've spoken with pointed out the difficulty to foil the foiler in reality. Something for artists?
From my very limited experience, it does depend on what "reality" you're talking about. In steady medium winds it's surprisingly easy (although it depends on one's sailing background, of course) but gusty winds or heavy conditions make it something else entirely.

I tend to think that foiling dinghies (and perhaps cats) will end up following the windsurfer model; that is, a very high proportion of them will move away from the mainstream sailing areas and clubs, and just sail in windier times and places. That may already be happening in places like Sydney, where only a very small proportion of the foiling Moth fleet does regular club racing.
Reply With Quote
Reply



Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Optimist AutoCad Vives Boat Design 16 04-13-2016
09:00 AM 
Not an Optimist so it's a Pessimist DCockey Boat Design 3 07-11-2013
05:15 AM 
New Rig for Optimist Doug Lord Sailboats 3 05-04-2011
04:07 PM 
Optimist Pram with.....spinnaker! Doug Lord Sailboats 0 12-24-2010
09:59 PM 
optimist pram restoration kayakn Boatbuilding 10 12-14-2008
06:15 AM 

Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.

All times are GMT -5. The time now is 05:55 AM.


Powered by: vBulletin Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Web Site Design and Content Copyright ©1999 - 2017 Boat Design Net