Hobie Cat Forums

It is currently Thu Oct 02, 2014 10:34 am

All times are UTC - 8 hours [ DST ]




Post new topic Reply to topic  [ 407 posts ]  Go to page Previous  1 ... 4, 5, 6, 7, 8, 9, 10 ... 28  Next
Author Message
PostPosted: Sun Apr 28, 2013 1:57 pm 
Offline
Site Rank - Captain

Joined: Sat Feb 18, 2012 11:47 am
Posts: 75
Location: Texas Gulf Coast/Dallas, Texas
Capt. can you tell me how you connected to top of the jib to the mast still allowing the mast to rotate? I've got something in mind but you may have something better or easier. THanks

_________________
"Riding The Island Wind" RIPIT (Tim)
'08 Red Hibiscus AI w/2013 replacement hull, Lovin' it!!!
'11 Golden Papaya AI (for a chap)
'10 Outback w/sail
'11 Tarpon 160


Top
 Profile  
 
PostPosted: Mon Apr 29, 2013 4:10 am 
Offline
Site Rank - Admiral

Joined: Wed Jan 25, 2012 5:30 am
Posts: 270
Location: Clearwater, Fl
I use aluminum tube with bearings that are pressed into the tube. The loop on the top of the sail goes over the large protruding bolt and holds the topper down. The piece that fits into the bearings is an aluminum rod reinforced with steel pipe (because one version actually snapped the aluminum). The steel pipe will rust some but not bad that high up. Also even though I'm using nickle plated bearings, they rust if hit with salt water. Even when they rust they still work very well. It doesn't matter since the mast topper only sees friction on the bearings when you're furling the main.

So all you need to do is source some strong aluminum that fits over your mast and find bearings that fit very snugly into the aluminum. I also have something inside the topper that the topper insert presses down against. Can't remember off the top of my head how I did that but there is a great deal of downward pressure applied to the mast by the topper insert. Let us know how it works out. Only a handful of us are experimenting in this area. And it is possible to break your boat.

I also have an aluminum frame that reinforces my bow. That's what the furler attaches to as well as the jibs downhaul. I don't have a good picture of that. Keith (Chekika) posted a good picture not too long ago of it but I can't remember where.

Image

Image

_________________
Jim


Top
 Profile  
 
PostPosted: Mon Apr 29, 2013 5:36 am 
Offline
Site Rank - Captain

Joined: Sat Feb 18, 2012 11:47 am
Posts: 75
Location: Texas Gulf Coast/Dallas, Texas
Wow, great minds do think alike. That's very similar to what I have in mind. Thanks for the pics. I'm ready to get started. It won't be long now.

_________________
"Riding The Island Wind" RIPIT (Tim)
'08 Red Hibiscus AI w/2013 replacement hull, Lovin' it!!!
'11 Golden Papaya AI (for a chap)
'10 Outback w/sail
'11 Tarpon 160


Top
 Profile  
 
PostPosted: Sun May 05, 2013 9:33 pm 
Offline
Site Rank - Captain

Joined: Sat Feb 18, 2012 11:47 am
Posts: 75
Location: Texas Gulf Coast/Dallas, Texas
I'm getting closer. I made some good progress on my AI jib today. Finish the mast topper except for a little welding and recut and finished sewing the sail. As soon as the cleats and swivel I had to order come in this week I can put this dude together. :D

_________________
"Riding The Island Wind" RIPIT (Tim)
'08 Red Hibiscus AI w/2013 replacement hull, Lovin' it!!!
'11 Golden Papaya AI (for a chap)
'10 Outback w/sail
'11 Tarpon 160


Top
 Profile  
 
PostPosted: Mon May 06, 2013 3:02 am 
Offline
Site Rank - Admiral

Joined: Wed Jan 25, 2012 5:30 am
Posts: 270
Location: Clearwater, Fl
Great ! Looking forward to the sailing report and some pictures once you test it out.

This weekend I was fabricating a bowsprint which extends the jib 18" forward. Also lowered the jib sail 7" so the whole setup looks quite different (to me at least). The performance should be better and if there's wind today it will be tested on the water. Only downside is the bowsprint is aluminum which might break or bend. But I like the flexibility. Plus the bowsprint had to be removable so the boat could be loaded into my truck. A simple hitch pin clip installs/removes the bowsprint.

Here's a picture of the aluminum bow frame if you're interested. This was taken last month by Keith. The front of it looks much different now with the bowsprint.
Image

_________________
Jim


Top
 Profile  
 
PostPosted: Mon May 06, 2013 11:54 am 
Offline
Site Rank - Captain

Joined: Sat Feb 18, 2012 11:47 am
Posts: 75
Location: Texas Gulf Coast/Dallas, Texas
Sounds good Jim. I have a question. Since the AI mast as a fair amount of flex do you loosen the jib line to allow the mast to flex or leave it snug?

_________________
"Riding The Island Wind" RIPIT (Tim)
'08 Red Hibiscus AI w/2013 replacement hull, Lovin' it!!!
'11 Golden Papaya AI (for a chap)
'10 Outback w/sail
'11 Tarpon 160


Top
 Profile  
 
PostPosted: Mon May 06, 2013 12:07 pm 
Offline
Site Rank - Admiral

Joined: Wed Jan 25, 2012 5:30 am
Posts: 270
Location: Clearwater, Fl
ripit wrote:
Sounds good Jim. I have a question. Since the AI mast as a fair amount of flex do you loosen the jib line to allow the mast to flex or leave it snug?
I have it kind of semi snug but not too much. You're right there is a lot of flexibility with the mast and the jib will move with the flexing. The flexibility (for me at least) seemed to introduce a sloppy leading edge of my earlier jib sails which didn't feel efficient. They bowed in the front somewhat like a candy cane. My newest Hobie sail has a sleeve built into the leading edge where I run a piece of 1/2" pvc pipe to keep it nice and straight. Helps with clean furling too. That works great for me and I just wish I would have figured this out earlier.

_________________
Jim


Top
 Profile  
 
PostPosted: Mon May 06, 2013 12:41 pm 
Offline
Site Rank - Captain

Joined: Sat Feb 18, 2012 11:47 am
Posts: 75
Location: Texas Gulf Coast/Dallas, Texas
CaptnChaos wrote:
ripit wrote:
Sounds good Jim. I have a question. Since the AI mast as a fair amount of flex do you loosen the jib line to allow the mast to flex or leave it snug?
I have it kind of semi snug but not too much. You're right there is a lot of flexibility with the mast and the jib will move with the flexing. The flexibility (for me at least) seemed to introduce a sloppy leading edge of my earlier jib sails which didn't feel efficient. They bowed in the front somewhat like a candy cane. My newest Hobie sail has a sleeve built into the leading edge where I run a piece of 1/2" pvc pipe to keep it nice and straight. Helps with clean furling too. That works great for me and I just wish I would have figured this out earlier.

I was talking to a Hobie 16 guru that works at my local Hobie dealer and he told me to put a sleeve in the leading edge of my jib (which i did) so I could run a small cable thru it connecting the cable to the swivel on top and the furler on the bottom. He said then tie off the top of the sail and cinch the bottom snug. He told not to worry about the flex in the main sail that it didn't need to flex really. So we'll see soon. I got my topper welded today and will assemble tonight. Just waiting on a swivel to come in now. It won't be long before I can try mine out.

_________________
"Riding The Island Wind" RIPIT (Tim)
'08 Red Hibiscus AI w/2013 replacement hull, Lovin' it!!!
'11 Golden Papaya AI (for a chap)
'10 Outback w/sail
'11 Tarpon 160


Top
 Profile  
 
PostPosted: Mon May 06, 2013 2:08 pm 
Offline
Site Rank - Admiral

Joined: Wed Jan 25, 2012 5:30 am
Posts: 270
Location: Clearwater, Fl
My earlier versions all had cables running through them with a swivel on top like your Hobie guru advised. Just wasn't right for my sails.

_________________
Jim


Top
 Profile  
 
PostPosted: Mon May 06, 2013 2:14 pm 
Offline
Site Rank - Old Salt

Joined: Sun Apr 20, 2008 6:18 am
Posts: 1336
Location: Sarasota,Key West FL
CaptnChaos :
That's the way I have my jib, I have the standard 7/8 dia aluminum mast rod that comes with the Hobie kayak sail up the sleeve in the jib (now it's just a standard Hobie kayak sail), I then put 7/8 alum tubing out the top to reach up to the top of the mast (much higher on the TI). Yes it still flexes some, but it kind of helps keep the jib in shape when the main mast is flexing all over the place (keeps the jib from turning U shaped on the front edge).
I also have a PVC rod (~1 inch dia OD PVC) on my spinnaker, it's only attached at the top and one bottom corner of the spinnaker, and gives the spinnaker something to furl onto when I furl it up. Seems to work great and isn't very heavy.

BTW: I weighed my mast topper, it weighs 4 lbs. ( not 20 lbs LOL), I could always take my mast up and down out on the water for low bridges and such, but it's a bit of a pain, perhaps adding the halyard will make it easier, I will also make a lighter carbon mast topper.

I finally got my trailer done, I was out of commission (sailingwise) for 3 weeks while our Yukon Denali was in the shop getting a whole new roof put on (rusted out from the kayaks), now I'm not allowed to put kayaks on the car anymore (wife was pretty upset about me trashing her $70k vehicle). During the down time I built a trailer for my TI. Now I'm thinking of setting up a halyard uphaul line for the jib and spinnaker similar to your setup. Since it won't be as easy as it used to be to tip the boat onto it's side to rig all the sails at the shoreline.


Top
 Profile  
 
PostPosted: Sun May 12, 2013 5:20 am 
Offline
Site Rank - Captain

Joined: Sat Feb 18, 2012 11:47 am
Posts: 75
Location: Texas Gulf Coast/Dallas, Texas
It's done! I finish the jib assembly yesterday and checked everything out in the driveway. Everything seems to work really well. This morning I'm going by Lowes to get some PVC tubing for the forestay. The cable I used is getting a lot of unnesessary twisting as I furl the jib. Capt. and Fushion told me this was the way to go but I had to try my way first. After that I'm head to the lake for a test run. It's a good day for it as winds are 5-11 NE.
Test report coming tonight.

_________________
"Riding The Island Wind" RIPIT (Tim)
'08 Red Hibiscus AI w/2013 replacement hull, Lovin' it!!!
'11 Golden Papaya AI (for a chap)
'10 Outback w/sail
'11 Tarpon 160


Top
 Profile  
 
PostPosted: Fri Jun 07, 2013 11:08 am 
Offline
Site Rank - Old Salt

Joined: Sun Apr 20, 2008 6:18 am
Posts: 1336
Location: Sarasota,Key West FL
I've been talking about these crazy wing sails for my TI for about a year now, I have finally completed my first wing sail ( 33 sq ft jib) and it actually survived my first wind tests (mounted on the boat (static)).
With Tropical storm Andrea going on, I ended up testing the sail out with the boat on the trailer in the front yard (way safer), since we had around 6 inches of rain, 40 mph winds and, and at least 6 tornados in the area today, plus huge surf (why I didn’t go out in the water).

Background:
About a year ago I read that wing sails are much more efficient (Americas cup and all), and because the way they work, there is much less heeling moment (the force trying to tip you over) when using wing sails. That was one of my issues with my original 35 sq ft jib (designed and built for my TI 3 yrs ago), when on a reach in higher winds, you could easily tip the boat over with all the sails deployed, plus severe weather helm when really pushing the boat (more so with the old rudder system). My original jib sail built 3 yrs ago finally wore out, and I have been studying for a year now learning all I can about wing sails with plans to replace all my sails with wing sails on my TI (talking about my plans on this forum, thus the reason for this post)). The reason being wing sails have an efficiency of 1.9 ( type E) (according to this article I read ( http://smalltridesign.com/masts/rig-mast_options.html ), whereas the standard TI sail (like my old jib) the best you can do is sail .85 (type A) times the wind according to this article. This stands to reason since TI's typically work out speed wise to about .6 to .8 of the available wind speed.

Here is the sail open (33 sq ft sail area)

Image

Here is the sail all furled up ( I furled it and unfurled it around 50 times today, I was even able to furl it easily in 30 mph gusts (Tropical Storm Andria was going on today)
Image

With the jib furled in a couple turns, it works as just a regular jib (the thick part is collapsed) ( discovered that today)

I now need two control lines to control the sail (the two lines work like the control bar on a kite so you can vary the shape and camber to suit), I'm still working on improving the control system.
Just like the old jib, it only takes a second or so to furl/unfurl the jib (I'm using the same 1 “ dia aluminum mast and PVC furler I had on my old jib, which works without any issues).

I had the sail out for a couple hours today in the front yard with winds 15-30 mph, making sure everything holds together, and flexing everything over and over again. When the gusts from the storm got really strong, I would furl it up and wait till things settle down (don't want to trash the darn thing before I get to use it).
The design I used is a conservative design with the average thickness of the wing being around 3 1/2 inches (about 10%), with the widest point being around 15% to 20% back from the front edge of the ‘length cord of the wing’. Since the wing is a soft wing and still flex's like a regular sail, I figured going too thick would be too low a reynolds number (too much drag in low wind conditions).

Lessons learned:
Wing sails are really complex, I probably wouldn't have started if I had known what I know now.
My original (non wing) jib sail 3 yrs ago took me a couple weeks to design and about a week to build, and around $30 bucks in materials (not including the cost of the old worn out Hobie kayak sail, that I used as a starting point). I used the jib for 3 yrs until it finally wore out. I've been designing this crazy wing sail for a year now, and construction has been over a month to this point, and I think I have at least another month of tweaking and adjustments. Was it worth it ( probably not). I’m over $100 dollars materials cost now (way over my limit).
Will I continue with my other wing sail designs, probably not for a while, I’m pretty burned out on all this now, though my wing spinnaker (screacher), would probably be really cool.
Is there any practical use for it (probably not)
Will it be more efficient than a standard jib of the same size, probably, but based on what I’ve learned, I now know why all boats don’t have wing sails (way too complex).
Will I do it again (NO) just wasn’t worth all the effort, too much thinking and not enough just enjoying sailing. Sails have been working just fine for 2000 yrs now with little to no change, who am I to change all that.
Are wing sails in all of our futures, probably yes, but let somebody else figure it all out, I’m pretty burned out on the subject now.
Some of my study sources are:
Tom Spear ( http://tspeer.com/).
Several boat design forums (Doug Lord and others).
This guys website has some interesting information ( http://wingsails.com/)
This guys rigid wing sail is novel but no way would I ever put anything like that on my TI (http://www.solidwingsails.com/ )
analysis and software used: Xfoil,Javafoil, and several others. All the 3D design work was done in Solidworks
Bob


Top
 Profile  
 
PostPosted: Sat Jun 08, 2013 7:15 am 
Offline
Site Rank - Deck Hand

Joined: Sun Sep 23, 2012 6:24 pm
Posts: 14
Hey Bob! It was great catching you pulling out at the boat ramp at Ft Desoto last Saturday and talking with you about many things especially this soft wing sail you have been working on for so long now.
That looks really cool! What better break test than during a tropical storm!
Lookin' forward to hearing how it actually performs or maybe seeing you out on the water somewhere sometime soon again...
Don

_________________
Don Haynes
Aka TriBlue

2005 Outback Red
2011 Adventure Blue converted to an Island

E-mail: haynesundr@aol.com


Top
 Profile  
 
PostPosted: Sat Jun 08, 2013 12:30 pm 
Offline
Site Rank - Admiral

Joined: Wed Jan 25, 2012 5:30 am
Posts: 270
Location: Clearwater, Fl
Quite interesting Bob. I always love seeing what you've done to enhance the performance of our islands. But I understand getting burned out by experimenting with enhancement designs. Best to step back for awhile and wait until you get fired up to jump back into the project. With a nice fresh mindset.

Let me if you decide to take your TI out and try the new sail. I'll be glad to join you and take video of the momentous event from my AI.

_________________
Jim


Top
 Profile  
 
PostPosted: Fri Jun 14, 2013 8:35 am 
Offline
Site Rank - Old Salt

Joined: Sun Apr 20, 2008 6:18 am
Posts: 1336
Location: Sarasota,Key West FL
Well the furlable wing jib sail design survived it's first encounter on the water.

Here is a pic of my TI with the jib out ready for launch.

Image

I spent the first hour out only flying the jib trying to get a handle on control and made a couple tension adjustments (I have several adjustable areas because I wasn't sure how things were going to perform). The wind was really low at first (under 5 mph) so I thought I was going to have to give it up for the day, but then the wind picked up a little to around 10mph. I have a bunch of tells on the sail to try and read, the trick is to adjust everything so they all point back.

When unfurled the sail becomes rigid and is on a free wheeling mount (makes a great wind indicator (LOL)). The sail when in neutral doesn't appear to create any drag on the boat, I was able to pedal easily in and out of the harbor without issue with the jib unfurled, so felt there was no need to furl the sail while out on the water. The sail does not luff or shake and rattle like a loose soft sail would when unpowered. When in neutral the sail is a symmetric airfoil (wing) shape creating no lift.

The sail automatically creates it's own asymmetric wing shape when tacking from one side to the other by utilizing the natural pressure on the inside and the vacuum on the outside, this part actually works perfectly, but you need to have at least 5-6 mph of wind to make it work, bottom line the sail is pretty useless in less that 5 mph winds unless your of course motor sailing, and can create your own apparent wind.

One big problem I had with my old original jib (also 35 sq ft, ( it was just a fairly standard single sheet jib sail)) was when on a reach with the mainsail and the jib out full, the heeling moment on the boat (the force trying to tip you over) was almost too much for the boat, and with the small TI rudder I would get weather helm pretty bad. As mentioned earlier in this post, this is when the boat would go into nautilus mode (the bow would go under water, and stay down 'just like sailing a submarine')

With this wing sail there appears to be no heeling moment at all that I could detect. When sailing a 90 degree reach with the wing in neutral, and the mainsail powered (the mainsail tells both streaming back) the boat got up to around 5-6 mph on the mainsail only (pretty normal for a lock stock TI with just a mainsail). The AMA was a third buried in the water (about normal). As soon as I pulled the single control line to get the jib sail to start working (it turns asymmetric when you pull on the control line), the boat sped up to 7-8 mph, and the windward AMA remained buried 1/3 of it's depth. I repeated the experiment several times by powering and depowering the jib and there didn't appear to be any change in the heeling moment. I was thinking man alive would something like this make a great kayak sail for my Revolution, I can't tell you how many times I was blown over on that and our Oasis by the wind with the standard Hobie Kayak sails. (probably a way better application than this jib).

My expectations on the wing sail were probably too high, I was expecting to be able to fly just the wing jib and have equal performance to the TI mainsail only, well that didn't happen (35 sq ft vs 90 sq ft (the math just isn't there).

In 10 mph winds the fastest I could get with this new wing jib alone was 3-4 mph (with the main furled), I was a little disappointed in that. However with both the jib and the mainsail working together the performance was better than expected. With the old jib you could see the mainsail deform a little from the accelerated air coming off the jib (slipstream) , one of my sailing friends had a name for that effect that eludes me right now. With the wing jib sail that deformation problem appears to be gone, and I get nice accelerated even airflow over the windward side of the main (giving it more power, that's kinda the way jibs work).

I am assuming that because of the shape of the winged jib (real narrow on top), it's effectiveness as a stand alone wing sail is greatly reduced, however it's ease of use (easy peezy), it's ability to stay open (unfurled) in neutral and not creating any additional wind resistance, it's ability to create a very smooth accelerated airflow to the windward side of the main, and the fact that there doesn't appear to be any heeling force associated with the wing sail might make winged jibs a possibility in the future once everyone get their minds wrapped around how they work.

I will keep this design and just use it for a while, everything appears to work as advertised except the furling. I ended up with the wing being 4 inches thick at it's widest point, and getting all that material to furl around a 1 inch mast ends up being a little bigger and looser than I had planned, not sure I would want to leave that 4 inch dia mess up in the air while sailing around with the jib furled. However leaving it open when not using it doesn't appear to have a down side. If I were to get caught in a storm or extreme winds I would likely furl it then drop the halyard and strap it along the side of the boat (like I'm currently doing with the spinnaker. When done for the day I just furled the jib and let down the halyard, leaving all the control lines and furler hooked up and laying the spinnaker, and jib over the seats (strapped down) for the ride home on the trailer. Didn't need that extra tractor trailer truck for hauling the rigid wing ( LOL).

I'm pretty sure I won't be designing a furling wing sail again (just not worth all the complexity and design headaches).
Bob


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 407 posts ]  Go to page Previous  1 ... 4, 5, 6, 7, 8, 9, 10 ... 28  Next

All times are UTC - 8 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 3 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group