Return to Hobie.com
Hobie Forums
It is currently Tue Apr 16, 2024 2:54 am

All times are UTC - 8 hours [ DST ]




Post new topic Reply to topic  [ 123 posts ]  Go to page Previous  1 ... 4, 5, 6, 7, 8, 9  Next
Author Message
 Post subject: Re: TI Jib
PostPosted: Sat Jul 30, 2016 11:44 pm 
Offline
Site Rank - Admiral

Joined: Fri Oct 24, 2014 2:13 pm
Posts: 161
Location: San Antonio, TX
tpdavis473 wrote:
Most jibs are not made to take forestay loads, they are usually made to hank onto a forestay or slide onto a forestay. If you make or buy a jib that is meant to be hanked on, you probably would be best served to add something that can take most (not all) the load. With the tiny loads we create on these boats, you don't need much in the way of a real forestay, but if you have some 1/8 or 3/16 inch dacron or polyester line or kevlar kite string it might make sense to install it along the luff just a tiny bit longer than the actual luff so as the luff stretches it will stop stretching when it reaches the limit of the additional line. That will help a lot to give you a tight luff. When I make headsails (either jibs or asymspinnakers), I typically put in such a line to reinforce the leading edge. The snuffing jib I use has one and the hand tension I use to hoist it is sufficient to give good shape to weather. I sewed mine inside the luff hem/tape, but you could just tie it off between the head grommet and the tack grommet and achieve the same result.

As an off-topic issue, if you want to point higher, you can change your mainsail to a pin top. Yah, it removes some power, but it improves pointing a lot. I did that on my Triak since my courses are nearly always upwind and downwind and sometimes against a big current, it is more beneficial to me to point than go a tiny bit faster on a reach. That being said, no trimaran is going to point very well.


Thanks tpdavis. My jib has snap hanks meant to snap to a fore stay. As I've seen others on here do, I currently have the luff tied to a length of PVC to give the sail something to furl around and to give the luff some structure. I'm not sure how well it's working out though. Even with the pvc, the luff is still pretty floppy and I feel it's only adding extra weight requiring more tension on the halyard. I'm currently making a few changes to it. If it still doesn't work out, I'm going to ditch the furler and pvc, then try your method with some reinforcement line in the luff. Then I'll haul up the sail and see what happens.

_________________
-- Chad | 2014 TI


Top
 Profile  
 
 Post subject: Re: TI Jib
PostPosted: Sun Jul 31, 2016 8:43 am 
Offline
Site Rank - Old Salt

Joined: Sat Oct 04, 2014 1:30 pm
Posts: 984
Location: Benicia, CA
Not only is the pvc adding weight (which causes more forestay sag and causes your jib to have more camber than it should), it is ruining the wind entry onto the luff causing turbulence and not allowing the luff to "see" the correct wind angle--both of which means you can't point.

You can make the sail furl around itself with a little stiffness added to the top and bottom. Add a short (1-2") metal plate bolted above the head grommet and one below the tack grommet. Make sure the edges have been filed/sanded or you will quickly wear a hole there...best to put the metal on the side opposite the direction of furl. When you furl from the bottom up, though, you will see it twist several times before the twist reaches the top furler...can't be helped. In your particular case, though, by getting a short luff jib, you will have difficulty furling this way because your line will twist, and twist and twist before the sail ever starts twisting--if you have a continuous furler, it will work, but if you have a single line furler, it won't work. But you can use that pvc from the mast head down to the swivel...might be ugly, though.

Furling from the bottom up is hard to do going to weather regardless, so if you need to furl the jib, you will have to fall off briefly.

_________________
R/Thom
SeaRail 19
Triak
BMW C600
Formerly Getaway with Custom Spinnakers
Formerly raced F24 Mk II


Top
 Profile  
 
 Post subject: Re: TI Jib
PostPosted: Sun Jul 31, 2016 9:26 am 
Offline
Site Rank - Old Salt

Joined: Sat Jan 14, 2012 8:24 pm
Posts: 780
Location: Houston, TX
Chad, I'm watching with interest to see what you come up with. I bet you figure something out. If you come to the conclusion that the jib just doesn't work out, let's get together and I can put my jib and its rigging on your boat in about 20 minutes. Then take it for a spin and see what you think. Furling into the main has many advantages. People probably think that the downside is you can't partially furl the jib or make quick adjustments in higher winds. Turns out not to be true. You have many options. Furl the jib completely if desired, furl the main a few turns leaving the jib fully out, ease the main to the point where the jib is all that really is powering the boat or furl both into each other until you create a lantern sail shape. All these options give you a nice, quick varied sail reduction needed for sudden changes in the wind. I can sail comfortably with gusts all around me by just keeping the main sheet in hand and easing the main instantly as needed during extreem gusts while leaving the jib fully out.

Hope you find a way to make it work. If you do, and it can be used with the spinnaker too, you may convert me. Otherwise you can always join me on the dark side. :lol:

P.S. If you know you will never have interest in adding the spinnaker then making a furler work with the jib is worth persuing it. Quickly changing from jib to spinnaker to jib is key in keeping me happy with this other option.

_________________
Greg

2016 AI - Spinn & Jib

“Out of sight of land the sailor feels safe. It is the beach that worries him.”
– Charles G. Davis

Image


Top
 Profile  
 
 Post subject: Re: TI Jib
PostPosted: Sun Jul 31, 2016 10:40 am 
Offline
Site Rank - Old Salt

Joined: Sat Jan 14, 2012 8:24 pm
Posts: 780
Location: Houston, TX
There is one very real downside to my rigging (jib furls into main), I never get to experience sailing by jib alone. One day I need to raise the jib via the spinnaker rigging just to see what it feels like to sail by jib alone.

_________________
Greg

2016 AI - Spinn & Jib

“Out of sight of land the sailor feels safe. It is the beach that worries him.”
– Charles G. Davis

Image


Top
 Profile  
 
 Post subject: Re: TI Jib
PostPosted: Sun Jul 31, 2016 11:15 am 
Offline
Site Rank - Old Salt

Joined: Sat Oct 04, 2014 1:30 pm
Posts: 984
Location: Benicia, CA
vetgam wrote:
There is one very real downside to my rigging (jib furls into main), I never get to experience sailing by jib alone. One day I need to raise the jib via the spinnaker rigging just to see what it feels like to sail by jib alone.


I don't know how much you would enjoy jib alone. Trying to go upwind that way will be pretty futile with bunches of lee helm. If the wind is big enough it might work, though.

If you want to go downwind with one sail, the spinnaker would be the choice. Lots of multihull mavens recommend that as a survival mechanism if you are stuck out in a big blow (and no lee shore, of course). Spins alone are safe because the luff is loose and any gusts from the side will collapse the spin and any overpowering gusts can be mitigated by just releasing the sheet. I sailed a few miles in 30+ kts and 4 foot seas in my Triak just spin alone. Was exciting fun because it was safe.

_________________
R/Thom
SeaRail 19
Triak
BMW C600
Formerly Getaway with Custom Spinnakers
Formerly raced F24 Mk II


Top
 Profile  
 
 Post subject: Re: TI Jib
PostPosted: Sun Jul 31, 2016 1:10 pm 
Offline
Site Rank - Old Salt

Joined: Sat Oct 04, 2014 1:30 pm
Posts: 984
Location: Benicia, CA
Another alternative to the PVC is Marlowe ProDrive antitortional rope...developed specifically for top down furling. It is expensive stuff at $6 per foot, but it may be on sale for half that sometimes. If you wanted to build a furling spinnaker, this would be the stuff to use in the luff.

Before this stuff existed, I had to create my own. It was not easy. I took some skinny line and threaded it through the center of some flexible tubing of small diameter (it is much easier to say than to do), then stitched the line to the tubing every couple feet. It worked but it was heavy. If I hadn't been doing a lot of single handed racing, it would not have been a worthwhile exercise.

_________________
R/Thom
SeaRail 19
Triak
BMW C600
Formerly Getaway with Custom Spinnakers
Formerly raced F24 Mk II


Top
 Profile  
 
 Post subject: Re: TI Jib
PostPosted: Sun Jul 31, 2016 6:04 pm 
Offline
Site Rank - Old Salt

Joined: Sun Apr 20, 2008 6:18 am
Posts: 3059
Location: Sarasota,Key West FL
Greg:
Actually I sail on just my jib all the time. Especially when out with other Islands I usually put my main away and just use the jib.
What I like about the jib alone is I have great control over the boat (no surprises).

Here is a video I made with the prototype jib just testing it all out. Everything worked great on all points of sail.

https://www.youtube.com/watch?v=ETwxZZMtyxg



I have no idea what it all means related to anything else.

FE


Top
 Profile  
 
 Post subject: Re: TI Jib
PostPosted: Sun Jul 31, 2016 8:05 pm 
Offline
Site Rank - Old Salt

Joined: Sat Jan 14, 2012 8:24 pm
Posts: 780
Location: Houston, TX
Looks good FE. That's the new jib you've been working on, correct? Is that while motor sailing or jib alone? (Now that i watched on a bigger screen, i can see this is without the motor) Looks like you were moving at a good clip with light winds. How does the new prototype performance compare to the old wing sail?

One of us needs come up with a cheap easy bow sprit that can just pop on and off the front of the bow with the click of a single shackle. Something as clever as Tom's trolling motor mount. I don't have the machine skills to make one like you are using.

The ultimate boat upgrades Hobie could make (in my book) would be to add a bow sprit and a motor mount.

_________________
Greg

2016 AI - Spinn & Jib

“Out of sight of land the sailor feels safe. It is the beach that worries him.”
– Charles G. Davis

Image


Top
 Profile  
 
 Post subject: Re: TI Jib
PostPosted: Sun Jul 31, 2016 8:44 pm 
Offline
Site Rank - Old Salt

Joined: Sun Apr 20, 2008 6:18 am
Posts: 3059
Location: Sarasota,Key West FL
Greg:
No that video is from 3 yrs ago on my first prototype wing design. I had the motors tilted up and was flying only the jib to test it out. Even though it's only 30 some sq ft it seemed to have almost as much power as the main, (don't know why). I just posted the video because you were wondering what it's like to fly only the jib. I'm happy to report running on just a jib works great.
FE


Top
 Profile  
 
 Post subject: Re: TI Jib
PostPosted: Mon Aug 01, 2016 9:09 pm 
Offline
Site Rank - Admiral

Joined: Fri Oct 24, 2014 2:13 pm
Posts: 161
Location: San Antonio, TX
I've been doing some tweaking, tweaking and more tweaking.

I first changed the way my furler/PVC mast assembly mounted to the bow so that it would help support itself in a raked upright position. I was hoping this would help keep the halyard tension down since it wouldn't have to fully suspend the PVC mast. I tested it out in the driveway (there was a slight breeze to give the sail some shape) but it looked like it wouldn't help much. So I ditched all the PVC and hauled up the bare sail. The shape looked MUCH better and the luff looked less baggy but after some testing of bringing the sail up and down, it seemed like it would be a pain in the butt to drop the sail and fold it up while on the water. So I tried furling the sail around itself, from the bottom, by hand and the sail seemed to furl pretty decently.

So I'm now going to try tpdavis's suggestion to make the sail furl around itself. I cut off all but a few inches of the PVC mast from my furler, then tied the tack grommet and the first hank to it. I had to do a bit of glueing on the furler, so after it dries, I'll do another driveway sail tomorrow. I'm feeling a lot better about this revision. Even if the sail doesn't furl very tightly, I'm thinking a loosely furled sail should at least be easy to take down, fold in half, then put away.

_________________
-- Chad | 2014 TI


Top
 Profile  
 
 Post subject: Re: TI Jib
PostPosted: Tue Aug 02, 2016 3:31 am 
Offline
Site Rank - Old Salt

Joined: Sun Apr 20, 2008 6:18 am
Posts: 3059
Location: Sarasota,Key West FL
Chad:
If you look at the furling jibs on H16's they seem to furl very tight without a mast. Something like that would be way better than my setup.
All my foresail masts are made from from Home Depot aluminum painting extension poles with cheapo PVC furlers mounted on them. The extension poles are around $30 bucks and the furlers cost me $5 bucks to make. Actually the aluminum masts are very strong and way lighter than PVC.
I never was able to overcome the floppy main mast problem because I never could get side stays to work correctly. The problem for me was if I made the main mast rigid with side stays, the main sail no longer worked properly. That's why I was so intrieged by that side stay setup with the bungy cords on them (brilliant solution). If I ever go back to a standard jib/genoa, (like a furling type H16 jib), I will likely use that setup.
Personally I think the easy furling ability is critical to function. In my experience the 40 plus sqft jib/genoa would be way too much sail except in the lightest winds. The problem that creeps up quickly is the heeling moment of the jib on a reach. Of course you can hike out to fix that, but it seems most don't like to hike out on their tramps, but if you do that you are at great risk of snapping the mast at the base (mast and sail sytem was never designed for that much force). Or you can do like I did and extend your AKA bars by 1ft on each side then most of the capsize problems go away, with the only caviate being my thousand dollar mast snaps off at the base long before the boat can capsize).
My opinion is having a bow sprit and angling the foresail so it creates lift solved a host of problems for me. With the worst issue being with such a large foresail in a batwing configuration (ie...main to one side on a barbor hauler, and the jib to the other side), the boat would go into nautilus mode, meaning the bow dives underwater and just stays down until you back off on the power (I'm never willing to back off). In this mode there is huge risk of pitchpoling the boat (I've pitch poled mine a bunch of times). The reason this occurs is because of lack of flotation in the bow, and because the main is mounted so far forward on the TI (to accommodate the extra seat). For the longest time I had hydrofoils on my boat to prevent the diving, but I was able to remove the foils once I angled the foresails (both the jib and the spin) via the bowsprit.
Another major issue I ran into with all those sails was the inherent weakness of the bow itself because of the big bow hatch. Under sailing load from the foresails the front of my bow would wave around up, down, and sideways as much as 5 inches, creating as much as a 1/4" gap in the hatch seal where water just pours into the hull. I was experiencing as much as 3-4 gallons an hour of water in the hull, plus great risk of actually folding the hull at the hatch opening (sucks when that happens). Actually the reason the Hobie jib option was abandoned was Hobie actually folded the bow in one of their TI's during the EC, so the whole project was abandoned.
Bottom line IMO, If messing around with this stuff It's probably a real good idea to re-enforce the bow with an aluminum truss sooner rather than later on these boats when adding exotic foresail systems. With the only exception being the Hobie spinnaker kit. Their spinnaker is very tiny and most of the force is forward (not sideways), so adding their spin kit is pretty safe, plus it's carefully designed so as not to exceed the mast systems and hull capabilities (a really solid design physically).
All I'm sayin is you can easily massively modify these boats to do anything you like, but just be cautious of the physical limitations of the basic design, and be aware of them before proceeding (vs after).
FE


Top
 Profile  
 
 Post subject: Re: TI Jib
PostPosted: Tue Aug 02, 2016 6:10 am 
Offline
Site Rank - Old Salt

Joined: Sat Jan 14, 2012 8:24 pm
Posts: 780
Location: Houston, TX
Due to that shorter bow and front hatch flex on the TI, maybe the jib on a TI should be smaller than the on on an AI. One more reason to switch our jibs one sail and see what the ideal size might be.

_________________
Greg

2016 AI - Spinn & Jib

“Out of sight of land the sailor feels safe. It is the beach that worries him.”
– Charles G. Davis

Image


Top
 Profile  
 
 Post subject: Re: TI Jib
PostPosted: Tue Aug 02, 2016 6:30 am 
Offline
Site Rank - Admiral

Joined: Fri Oct 24, 2014 2:13 pm
Posts: 161
Location: San Antonio, TX
Thanks FE,
So it's aluminium, painting extension poles that you are using! For some reason I thought you were using PVC for the masts, but now that I think about it, I seem to remember reading about the painting poles. Guess I should have re-read the Ultimate Tandem Island thread! Couldn't have done all of this without it, by the way. :D

I have my bow braced with square aluminium tubing and I only plan to use the jib during light winds (when the wind is blowing, I have plenty of fun under the main sail alone), so I'm hoping that I'll be good when it comes to breaking things. Currently, I have a rear stay, but once I have the jib worked out, I want to experiment with replacing the rear with side stays, probably also on bungees. Then I'd be able to cut off the extension arm, making the topper lighter. I'm thinking side stays tied off to the front of the topper, where the halyard attaches, would better keep the topper from rotating as the jib gets blown off to the leeward side. Although maybe not, if the stays are on bungees, as the bungees would just stretch. What do you think? I also like the idea of side stays giving the mast a bit of extra side-to-side support.

This boat has been keeping me in the garage too much lately, but it is fun to modify these things!

_________________
-- Chad | 2014 TI


Top
 Profile  
 
 Post subject: Re: TI Jib
PostPosted: Tue Aug 02, 2016 6:33 am 
Offline
Site Rank - Admiral

Joined: Fri Oct 24, 2014 2:13 pm
Posts: 161
Location: San Antonio, TX
vetgam wrote:
Due to that shorter bow and front hatch flex on the TI, maybe the jib on a TI should be smaller than the on on an AI. One more reason to switch our jibs one sail and see what the ideal size might be.


Very true. The next time we sail together, we should swap out jibs and see what happens. Now that I'm rigged up for one, it should be even easier! So, do the AI's have less bow/hatch flex that the TI's? I would have thought the opposite since the AI bow is longer.

_________________
-- Chad | 2014 TI


Top
 Profile  
 
 Post subject: Re: TI Jib
PostPosted: Tue Aug 02, 2016 11:28 am 
Offline
Site Rank - Old Salt

Joined: Sat Jan 14, 2012 8:24 pm
Posts: 780
Location: Houston, TX
Yes, there is less flex. But... I have been taken in more water gradually over the last few years since introducing the jib so I could be fooling myself.

_________________
Greg

2016 AI - Spinn & Jib

“Out of sight of land the sailor feels safe. It is the beach that worries him.”
– Charles G. Davis

Image


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 123 posts ]  Go to page Previous  1 ... 4, 5, 6, 7, 8, 9  Next

All times are UTC - 8 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 2 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

Jump to:  
© Hobie Cat Company. All rights reserved.
Powered by phpBB® Forum Software © phpBB Group