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Nacra 5.2 rigging

Posted By: wecycle

Nacra 5.2 rigging - 05/13/19 12:14 AM

Main halyard
I seem to have a difficult time raising the mainsail the last 6 feet or so. Is there a trick to making the channel in the mast more slippery? I have tried liquid soap and silicone spray. This helped a bit but did not cure the issue.

The main halyard wire portion broke at the locking ball. It looks like I need a new wire portion and should renew the rope portion at the same time. Will 1/4" dyneema type line be suitable for this? is there an other option for the main halyard?

Forestay
I have installed a roller furler, resulting in the forestay being too long. This results in extreme mast rake. I calculate 9" that it needs to be shortened, including 2" due to the bridle wires attaching to the tangs on the side of the furler drum, 2.5" for the length of the furler and 4.5" for the length of the upper swivel. I am looking at using a swageless eye fitting for 4mm cable to shorten the forestay. Online info seems to say 222" is stock, so shortening to 219" should be right. Anyone have better data for this, or a better strategy to fix the forestay length?

Quick release lever
Would I need to shorten the forestay an additional 8" if I install a Johnson Hyfield quick release lever type shroud adjuster in the forestay with the roller furler?

Thanks in advance for any advice.

Dennis in Richland, WA
Posted By: JeffS

Re: Nacra 5.2 rigging - 05/31/19 09:41 PM

Having that trouble raising the main sail could be obstruction in the mast or the mast is prebent to the wrong shape for the sail, to make sure there is nothing in the sail track I use a scouring pad bent in half so that when you insert the bulging bent bit in the mast track like a sail it won't pull out and then I scour the inside of the track and you can feel if there's any obstruction. If you lay your mast on the ground then stretch your sail out on the mast but not in the sail track, you may find that the shapes don't suit each other so you can adjust your spreader arm settings to suit.
Posted By: northsea junkie

Re: Nacra 5.2 rigging - 06/04/19 07:43 PM

Originally Posted by JeffS
. If you lay your mast on the ground then stretch your sail out on the mast but not in the sail track, you may find that the shapes don't suit each other so you can adjust your spreader arm settings to suit.



Each catsail has a curve in their frontleech. So its not a straight line but there is a point where the curve is at its max. This is called the external camber of a sail. Hoisting that sail in a straight mast track will always cost you extra force because the frontleech doesn't follow the straight line of the mast. The greater this external camber is, the more trouble you will have with hoisting.

When you bent the mast with spreaders you will make the effect of the external camber again smaller. But don't forget that only this external camber will create the vortex of the sail when pulling the downhaul!
So only because of that your sail becomes the aerodynamic motor you want it to be.

P.S. external camber may never be negative; that's why sailmakers often cut to much camber in their sails. In fear of too much bend masts.
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