Building Shesha, a Hunter Valley GIS, Australia

[woodeneye]

It is a little bit less than 90.

Maybe I should make the plan $19.95?

Maybe not, our high AU$ has already given you a nice pay cut

[Boatmik]

I think $20 will become 19.95 before the end of next week.

[woodeneye]

The weather is not looking too bad for some freshwater sailing on Grahamstown Dam tomorrow (Saturday). Wind is forecast to be 25 knots* and it looks like I’ll be solo, so I better make sure that I have my reefing cords! With a breeze like that, hopefully my eldest daughter can make it. It should be a good test for the new stiff aluminium yard. Grahamstown Dam

EDIT: Wind speed has been revised up to 35 knots tomorrow

Attachment 150267

[Boatmik]

Will be very interesting, keep us all posted (as you always do!)

MIK

[woodeneye]

Well, sadly no sailing was possible this w/e due mainly to the extreme weather. Wind was gusting over 100km/hr yesterday. Today the wind on the coast was still around 50km/hr so solo sailing was ruled out as well. However I put in about 3 hrs of "driveway sailing", improving the boat, so it wasn't entirely wasted

I changed a few things today as I was trying new stuff that I hadn't had the chance to do before. You don't get to do this if you're sailing!

I added a clam cleat to the top of the yard to make adjustments of the head easier, and made some marks on the pole for various settings. It's amazing how sensitive the head of the sail is to quite small changes in tension.

I removed the pulley from the halyard, but soon put it back as the effort to raise the sail is just too much without it.

I also installed a u-bolt for the kicker when the time is right to start playing with that.

The most interesting thing I changed is the location of the traveller and the positions of both boom blocks. I've moved the traveller aft to the first gunwale spacer and added a clamcleat to make adjustment easy. The mid block on the boom has been moved for'ard relative to the ratchet block on the seat. The sheeting changes have made a big difference to what happens when the sail is sheeted in hard, as I'll explain...

Previously when sheeting in hard, the boom was being forced forward in opposition to the downhaul. The boom moving forward was changing the balance of the boat as well as causing unnecessary and excessive boom and mast bend. With the new arrangement, the sheet is pulling the boom aft and the effect has been made to keep the boom in a neutral fore/aft position when sheeted in for upwind sailing. The mast doesn't bend as much now and also most of the bend in the boom has also been eliminated. So much so that I may not need to build a new boom, but we'll see. I was quite surprised that the effects were so dramatic. See pics...

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[Boatmik]

Great rundown,

Where did you put the eyebolt?

MIK

[woodeneye]

Great rundown,

Where did you put the eyebolt?

MIK

Am looking forward to seeing the how the changes work on the water. I forgot to mention that I also shortened my tiller extension by about 200mm as it was banging into everthing when tacking and the crew would get the occasional whack with it too (Unintended!). I can still perch on the rail over the mid seat though.

The U bolt is installed into the mast partner in front of the mast. Is this spot OK? I thought about locating it on the mast step but the vang might make life uncomfortable for the crew.

[Boatmik]

Am looking forward to seeing the how the changes work on the water. I forgot to mention that I also shortened my tiller extension by about 200mm as it was banging into everthing when tacking and the crew would get the occasional whack with it too (Unintended!). I can still perch on the rail over the mid seat though.

The U bolt is installed into the mast partner in front of the mast. Is this spot OK? I thought about locating it on the mast step but the vang might make life uncomfortable for the crew.

Crew schmoo.

Only kidding - but I do joke that the ideal length of the tiller extension should reach the crew in their normal position.

When tacking the tiller extension and boat heel is all I really watch - the tiller extension points to one of the blocks on the boom.

MIK

[woodeneye]

I had a great sail today at Taylor's Beach on Port Stephens. In the morning the wind was very light, and there wasn't enough pressure to keep the sheets from dragging in the water on the runs. The water was absolutely flat, so when the breeze picked up at mid day to around 6 knots, it was just awesome sailing on the flat water.

This was my first sail in Hakuna Matata in a gentle breeze on my own, and it was fantastic. When the pressure kicked in she fairly picked up her skirts and burbled along nicely. An hour later and the breeze had freshened to about 10 knots, with just scattered white caps, and the water was still flat. The Goat really flies in these conditions. On the reaches I could just sit comfortably on the rail, with the occasional stronger puffs needing a bit of hiking to keep her flat.

To windward I needed to flatten the sail a bit as the bag I had set up was just a bit too powerful. By myself, I found that I could adopt a comfortable hiking position similar to that used by Star sailors. With the rear foot under the strap and the other leg bent up along the gunwale and that foot hooked under the mid seat, I could sit with my behind over the side like that for ages. The two ratchet blocks, one of them automatic, make holding the sheet very comfortable. I have a Harken on/off ratchet fixed to the mid seat (off a Paper Tiger and given to me by my brother), and a Ronstan series 55 automatic ratchet is attached to the traveller. The Ronstan was kicking in when the breeze got to around 8 knots, which is just about right for me. They are expensive, but I think worth every cent.

All the changes I've made to the boat recently have paid off nicely. The new, stiff aluminium yard is just what was needed, and gives me a nice sail with more flexibility to have the power when I want it, but can still depower when things get too much.

Moving the traveller even further back to the knees has also worked extremely well and it means I can control the downhaul better because the boom is not being pushed forward any more when I sheet in.

However, I have some fine tuning to do with the new yard as I have lee helm on the beats. It's terrible, because I like to pinch up a bit when the gusts hit rather than letting the sheet out at bit, and with a bit of weather helm, it helps a lot. With lee helm I have to push the tiller to move the bow up when she heels....very unnatural.

The halyard is currently attached at the 47.5% mark from the front of the yard, so I think this needs to be moved forward to 40%, and then see where things need to go from there. Let me know if this isn't right.

The other thing I'm really happy with is the new trailer which allows me to launch and retrieve all by myself. However, there were the usual helpers who are intrigued by the boat and will come over and lend a hand anyway The GIS is such a magnet! As a result of today, three people will be checking out the GIS on the web tonight. It just cant help but invite attention, especially when they see how well it moves, and how light it is to handle. One bloke with a trailer sailor came over saying he just had to come and look at the rig. He could not believe how quick we were moving and he wanted to see how the thing worked. He had never seen a balanced lug before and from his boat on the water couldn't work out how it all worked, and was marvelling at how simple it was. Well, we're all converts here who know that "simple" does not have to mean "slow" .

I managed to get a couple of quick pictures, and a terribly jerky video, all taken with my phone, but I need a cable to connect it to my PC to transfer them. After having drowned one camera already, I wasn't going to take my new one out there.

And lastly, summer is here at last and I can sure tell from looking at my face. I need a better sunscreen than the one I used today...

[davlafont]

The halyard is currently attached at the 47.5% mark from the front of the yard, so I think this needs to be moved forward to 40%, and then see where things need to go from there.

That would make sense, move the center of effort aft...

[IanHowick]

However, I have some fine tuning to do with the new yard as I have lee helm on the beats. It's terrible, because I like to pinch up a bit when the gusts hit rather than letting the sheet out at bit, and with a bit of weather helm, it helps a lot. With lee helm I have to push the tiller to move the bow up when she heels....very unnatural.

The halyard is currently attached at the 47.5% mark from the front of the yard, so I think this needs to be moved forward to 40%, and then see where things need to go from there. Let me know if this isn't right.

If you had a boom vang on, you could move the whole rig further aft/have less sail in front off the mast. You lose the self vanging of the balance lug, so need that vang to compensate.

This is how Keyhavenpotter sets his scow up for racing, so presumably less of the rig in front of the mast is faster as well if you can get the boat balanced and keep good control of the sail shape. Great to get some feedback on how the stiffer yard is working!

Ian

[woodeneye]

If you had a boom vang on, you could move the whole rig further aft/have less sail in front off the mast. You lose the self vanging of the balance lug, so need that vang to compensate.

This is how Keyhavenpotter sets his scow up for racing, so presumably less of the rig in front of the mast is faster as well if you can get the boat balanced and keep good control of the sail shape. Great to get some feedback on how the stiffer yard is working!

Ian

Hi Ian

I have a boom vang made up and a U-bolt installed, but didn't use it yesterday as I have made so many changes to my rig lately and didn't want to confuse things. But yes, you're right that if the rig is moved back, the downhaul loses its vanging effect and effectively becomes just a luff tensioner.

MIK and I have had some discussion about some ways to set up the vang, as the pivot point will always be off-centre and the setting will change with the boom angle.

Apart from controlling the leech, the other reason why a separate vang will be good is to give more control of the boom position on broad reaches and runs. The vang will allow me to move the boom across the mast a tad more to help balance the rig and so reduce rolling. Also to prevent too much twist and the end of the yard going ahead of the mast.

I forgot to mention that I had a close-up encounter with two dolphins yesterday. A female and her calf came up pretty close from astern before disappearing. By the time I saw them they were already almost alongside. They were cruising very purposefully, and while they looked slow, they were actually moving quite fast. Too fast even for a GIS!

Edit: It's interesting to see how differently each of those scows has the vang/downhaul set up. I might try it next time out.

[Boatmik]

I will have to have a closer think about all of this, but am pedal to metal at moment doing some less obvious marketing stuff (to try and claw back some of the differences because of the OZ dollar).

However ... the above discussion looks at the symptom and tries to resolve it - the lee helm issue.

This is how older people end up on 27 types of medication.

What about a fresh look and some intuitive guesses about why it might be happening. To me it is completely counter intuitive.

The leach should be firmer, under more control that will REDUCE lee helm. Very interesting that the opposite is observed. And that it is large enough to change the sailing characteristics! Amazing

Wonder, is the draft has moved further forward because of no taper in the yard? Or something like that.

Also as a check of basic settings - I would imagine you are carrying about a 1 in 10 draft or a bit fuller than that in the foot of the sail - that would give you more weather helm if not being done at this point - but I imagine it is implemented.

MIK

[woodeneye]

MIK

Reducing the draft still left me with a fair amount of weather helm. My old wooden yard had the halyard attached at 45% from the front, so not a lot of difference to this one, but still a few cm in it. The boom is higher though, so perhaps that is the reason?

Never mind, next weekend's mission is to get the trim right, so, judging from the amount of lee helm I had, I'll go straight to my 40% mark and then tweak from there. These things are not really problems because they are just tuning matters and my experience is that small changes can have big effects on the helm, so I'm not worried about it.

Because my daggerboard slot is shaped, I cannot trim the board fore and aft, so all the adjustment is in the rig.

[callsign222]

This is interesting, because I've never had any lee helm, and I've moved the rig back and forth quite a bit until I found a really nice sweet spot.

One thing to consider, in lighter airs, the rudder is so well balanced that just the weight and lever-arm of the tiller pulls in the direction of the downward leeward (heeled) side so it can make it feel like a bit of lee helm, but once the speed picks up, the rudder forces over ride this gravitational pull of the tiller. Make sense?

My tiller is also 30cm longer than the plans so I can still steer from way forward, so this could be exaggerated for me since the lever arm is longer.