Splashed my new to me '83 5.0 for the first time last Thurs.. I have a list of things to work out, but here is the the most serious one that I'm aware of. As the mast rotates, the shroud wires brush over the diamond wires' upper attach point. Obviously, metal to metal contact by itself is not good, but even worse, the shrouds are getting caught in the diamond wire fork and between the clevis pin head and fork. I had to manually clear this jam after nearly every tack and jib. I took the mast down today to check for damage to the rigging and it appears, to my amazement, that nothing is hurt. Comments, fixes etc. please. Surely this has come up before, but my searches turn up nothing. Note, my mast has the straight tubular spreader, not the triangular link swept back spreader.







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Hobie 16 (3 formerly)
MacGregor 25 (formerly)
Chrysler Dagger 14 (formerly)
NACRA 5.0 (currently)
High Point, NC
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All the sharper guys I know just put a ball or tube on the side stays to keep the wire off and away from the mast and diamond attachment points. Simple, dependable and reliable.

Thanks doublehull. I'm planning to try those as fixes as well as a shorter grip clevis pin (so the head doesn't stick out) and spacer washers on the mast side of the the fork and tang (to minimize the gap between the outer side of the tang and outer side of the fork).

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Hobie 16 (3 formerly)
MacGregor 25 (formerly)
Chrysler Dagger 14 (formerly)
NACRA 5.0 (currently)
High Point, NC
--

A shorter clevis pin with the head of the pin towards the mast would allow the diamond wire anchor plate to be adjusted closer to the mast. You might also gently and cautiously clamp the the 2 ends of the fork together closing the gap.

R



Edited by the-renovator on Oct 14, 2015 - 11:20 AM.

I had a look at both Nacra's today. The photo is an '88 5.0, but the '84 5.7 is the same geometry.
There is no way the shroud will touch the diamond wire.
I can get you the measurements between the hound & mast head, & diamonds when we put the boats away. Probably the next 2 weeks.
I'm wondering if a PO cut down a longer mast, (5.2 or 5.7?), moved the hound, or pre '84 used a different geometry?
My diamond wire tangs are folded almost tight against the mast, it is difficult to get tape in there to secure the ring dings.
If I rotate the mast the shroud hits the mast almost exactly where it appears to in the photo. The other diamond tang is well inside the shroud, there is simply no way they can ever touch.
The difference appears to be where your diamond are attached, on the side vs nearly the front for my boats.




Edited by Edchris177 on Oct 15, 2015 - 01:37 AM.

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Hobie 18 Magnum
Dart 15
Mystere 6.0XL Sold Was a handful solo
Nacra 5.7
Nacra 5.0
Bombardier Invitation (Now officially DEAD)
Various other Dock cluttering WaterCrap
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Thanks Ed and the-renovator.

Here is what I have found/done.

The clevis pins that came with the boat were indeed too long. I replaced them with a shorter pin with less grip:



Since the inside fork width is wider than the tang, the fork can move away from the mast up to the difference in those two dimensions. To get the fork as close to the mast as possible, I installed washers between the tang and the fork on the mast side:



Lastly, I slid clear vinyl tubing over the entire fork/tang assembly, 1/2" ID X 5/8" OD X 8" length. It is a very tight force fit at the top:



I sailed the boat yesterday for a couple of hours in 8-15 kts. with no jams or hangs. So, maybe problem solved.

Note First Impressions:

With me, 180 lbs. and crew 170 lbs. the warp drive engaged at about 12 kts., hard hiking no trap, crew just in front of shroud, me way back the boat balanced well about 4" of lee bow above water, windward hull lightly skimming. In hard hits 15 kts. and up I had to dump some main to keep from burying the lee bow.

The boat seems stern heavy and I'm only running about 4 deg. of mast rake??? In lighter conditions we had to get very forward on the boat to get the bows down about half way.

Film at 11.

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Hobie 16 (3 formerly)
MacGregor 25 (formerly)
Chrysler Dagger 14 (formerly)
NACRA 5.0 (currently)
High Point, NC
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Don't be afraid to bury your leeward hull when you're driving it hard. I routinely bury my leeward bow until only about 1" is above the water. When you push the 5.0 or 5.7 you need to get the bow down, as your skegs are rising and have much less effect. Your bows become your skeg. I've buried mine several times up to the crossbar and haven't pitchpoled it (yet). A couple of times I've stuffed the crossbar a good foot under water. The boat just slows for a second, pops up, and accelerates like a scalded cat. I have heard of people getting the sterns up too far though and having the boat suddenly slide sideways to weather in kind of a "spinout" motion. Guess I need to start pushing harder.

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Tim
81 Hobie 16
87 Nacra 5.7
Austin, TX
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With those incorrect clevis pins being too long and installed the wrong way, I'm pretty sure the diamond wire tangs were bent away from the mast, shorter pin installed correctly with pin head against the mast, gentle palm and body weight pressure would bend the tang back against the mast. I do like your clear vinyl tubing idea, gonna adapt that to prevent those scrape marks on the mast from the trap wires