Thread: OZ vs Kiwi

da mit - am I so transparent!!!!

When I was racing boats I started off with every possible adjustment leading to hand on the gunwale. Later I started to put them so the ropes were the shortest possible while being reachable.

Once I got into design ... set up everything right and have a minimum of adjustments but have a really big sail to overcome inefficiencies.

AND A BIG DOWNHAUL.

MIK

Originally Posted by BradLH

Rick,


When I built my OZ I was planning to do some serious racing so I added extra controls and used the aluminum mast and spars but I'm not recommending anyone else do what I did. Like Mik says it does add expense and complexity. 99.9% of the OZ builders will be very satisfied with the boat if they build it exactly as he designed it.

Brad

Well, 99.9% seem to be doing quite well in the racing. Oz boats are the World Champion in 2009 and 2010, Canadian Champion, Iron Duck race winner and Sail Oklahoma PDR race winner. Seems like a nice racing pedigree to me!

Rick.

My plans attract better sailors - that's part of it too.

Or maybe more and harder downhaul?

MIK

Originally Posted by Boatmik

My plans attract better sailors - that's part of it too.

MIK

Much better looking too...........the boat that is not the sailors.

Originally Posted by pdr311

Well, 99.9% seem to be doing quite well in the racing. Oz boats are the World Champion in 2009 and 2010, Canadian Champion, Iron Duck race winner and Sail Oklahoma PDR race winner. Seems like a nice racing pedigree to me!

Rick.

You left out 2010 SDDP winner

The reason I said 99.9% is there will always be the 0.1% of us who are never satisfied and will always be looking for a little bit more speed.

Brad

This is a photo of my OZ in a gust. If you enlarge it you may be able to see that vang has the boom bowed but the head is still twisted off depowering the sail.

Needs more downhaul

Brad

Hi Brad,

Looking at the sheet angle in the pic .... do you have the block running free on a rope traveller or is the block tied in a central postion.

That's one of the differences between the lug and sprit rigs.

Sprit is completely self vanging because of the sprit boom - so the traveller doesnt' need to tension the leech of the sail and reduce twist.

Lug is partially self vanging (yours more!) - but behaves much better with the block sliding on the traveller so that when tensioned the boom is pulled down and the sail detwisted.

However in the gust pic above ... it is possible/probable that the traveller is sliding but the sail has been eased for the gust and it is just the photo angle that makes the sheet look like it goes to the middle of the boat.

How is it set up Brad? And do you have comments - I know you spent a couple of months trying to improve the boat.

Also can you tell us the diameters and wall thicknesses of your spars.

MIK

Originally Posted by Boatmik

Hi Brad,

Looking at the sheet angle in the pic .... do you have the block running free on a rope traveller or is the block tied in a central postion.

That's one of the differences between the lug and sprit rigs.

Sprit is completely self vanging because of the sprit boom - so the traveller doesnt' need to tension the leech of the sail and reduce twist.

Lug is partially self vanging (yours more!) - but behaves much better with the block sliding on the traveller so that when tensioned the boom is pulled down and the sail detwisted.

However in the gust pic above ... it is possible/probable that the traveller is sliding but the sail has been eased for the gust and it is just the photo angle that makes the sheet look like it goes to the middle of the boat.

How is it set up Brad? And do you have comments - I know you spent a couple of months trying to improve the boat.

Also can you tell us the diameters and wall thicknesses of your spars.

MIK

Mik,

My traveler block is tied in the center so I can get the boom closer to the centerline going upwind. I sheet the boom in about halfway between the corner and center of the transom sometimes, usually in moderate to heavy air when I'm on the verge of being overpowered, My thinking is if I have good speed up wind I may as well sheet in hard and point higher. If you think it would be better to have the block running free I'll try it

My OZ would point higher than any other boat at the Oklahoma messabout. That includes the fiberglass production boats, but I wouldn't consider any of them high performance.

The sheet is eased a bit in the photo. I'm an out of shape, gray haired, fat guy so I don't hike hard unless it's absolutly necessary

The mast is 2.5" od, boom 2" od and yard 1.5" od. All 6061 T6 with 0.065" wall. I'm going to use the same 2" boom material on the Sabre, it may bow quit a bit with the mid boom sheeting and more powerful vang but I think it will work.

Brad

A lot of sabres put a sleeve in the boom - just take the same section and slot it so it fits inside. I would guess about 18" long.

The optimum sheeting angle most of the time for the front sail is about 10 degrees - rarely comimg in narrower - so have some knots or stops on the PDR traveller (lug rig only) at those points.

Try it anyhow and see how it works in medium and stronger winds. Basically when you want the rig to be powerd up the correct mainsheet tension should just unload the vang.

MIK