Nacra 5.0 center beam :: Catamaran Sailboats at TheBeachcats.com

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Nacra 5.0 center beam

ohmsj

Rank: Mate

Registered: May 07, 2004

Last visit: Nov 14, 2019

Posts: 141
Posted: Oct 28, 2014 - 09:57 PM

I recently picked up a Nacra 5.0 that seems to Factory install center tube similar to the N5.2 only the tramp goes under the tube without attaching to it. After looking at as many N5.0 as I could find on line I did not see one with a center tube so the question is did nacra put out a 5.0 with a center support tube or was this added by someone along the way? Other than keeping the front and rear beams from rotating I not see any need for it. Since the front and rear beams are bolted to the hulls that eliminates the rotation issue. So what is it there for?

Any thoughts from the Nacra guys

Thanks

--
Jeff O
N5.0
solcat 18(sold),
N5.2,
H16
Camarillo CA
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Edchris177

Rank: Chief

Registered: Nov 26, 2009

Last visit: Aug 10, 2024

Posts: 2531
Posted: Oct 29, 2014 - 08:02 AM

It looks in pretty good shape, not many still have the end caps.
What year is it?
The earliest 5.0's I have seen are '83, & none have the beam or jib tracks. The PO might have added the jib tracks.
Measure the hull length, is it really 5.0?
The early ones just used the 1/2 moon chocks & studs in th ehull, no centre beam. By '84 they went to beam straps.
I wouldn't worry about the traveller for now, as long as it rolls smoothly, lots of older 5.2's & other boats used that style. They are plenty strong, just be careful if you decide to remove the car. The "wheels" are not attached, they just sit there on very short studs. They will fall off & those tiny SS bearings are impossible to find after it happens, nor can they picked up with a magnet. There are still 8 or so of them on the forest floor in my backyard!(From a 5.2 we wrecked)
If you decide to change it, you will also need to replace the track.
If you elect to go to the 1 1/2" ball, you will need to change the mast base, DS rod, beam strap, & saddle the rod sits in. Also drill a new hole in beam & replace the compression tube. The old system is a smaller diameter rod, they were prone to bending...but you already know the importance of rotating the mast when raising or lowering.
Our season is just about done. You will enjoy that boat, they suffer a bit in light air, but when the wind picks up they rock. Going to weather get right up to the front beam so as to push the lee bow way down, use the fwd trap if need be.
I took ours out yesterday, the forecast was for BIG wind, but not til the evening, so I went. The first 30 minutes were great fun, then the wind picked up, the buoy showed 29 mph. I scooted back into the bay to escape the building seas, blasted around for another 1/2 hour, then retired as I thought it was getting to the point of breaking things.
If you are 200lb, you can solo right just by hiking. They carry 2 adults just fine.

Edited by Edchris177 on Oct 29, 2014 - 08:04 AM.

--
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
--
ohmsj

Rank: Mate

Registered: May 07, 2004

Last visit: Nov 14, 2019

Posts: 141
Posted: Oct 29, 2014 - 10:28 AM

Ed
Thanks for all the insight, The boat seems to be in very good condition, it is listed as an 83 and had some old graphics that indicated it is a 5.0. It does have the ½ moon chocks under the bolts in the beams and no sign of straps.
There are a few things I would like to change like taking off the center beam, do you see and downside or reason not to take it off? I took it off my 5.2 and really like the fact I am not beating up my knees in a tack.
I need to change the DS rod and ball but Murrays is up to $220 for the kit. That just seems like a lot of money for the parts. I can make the threaded rod for a lot less by buying the 9/16” SS rod and running a die over it. That leaves the mast base and ball to buy so not quite as bad.

I do have another question regarding the front beam, it has a block a cam-cleat that looks like it may have been a barber hauler? And ideas on what this setup is for? Photo below

I am also looking for NACRA graphics / decals if anyone has a line on some.

Thanks for the input.

--
Jeff O
N5.0
solcat 18(sold),
N5.2,
H16
Camarillo CA
--
Wolfman

Rank: Chief

Registered: Jun 24, 2009

Last visit: Jun 15, 2023

Posts: 1555
Posted: Oct 29, 2014 - 08:09 PM

If it doesnt have straps you probably shouldn't take off the centre beam. That is a lot of stress on the bean chocks otherwise. It should be that much of a pain. The cleats are for the mast rotator. I wouldn't even bother rigging that. Talk to Pete begle and dan Berger about possible spare parts. Pretty sure you can get the decals from Murray's.

--
Dave Bonin
1981 Nacra 5.2 "Lucile"
1986 Nacra 5.7 "Belle"
Winnipeg, Manitoba, Canada
--
Edchris177

Rank: Chief

Registered: Nov 26, 2009

Last visit: Aug 10, 2024

Posts: 2531
Posted: Oct 30, 2014 - 06:49 AM

QuoteAnd ideas on what this setup is for? Photo below

I think it is for mast rotation. That was added, it was an option on the boomless boats. I removed mine on the 5.7. It helped a bit downwind, but the greatest advantage was in really light or flaky wind. You could lock the mast in one spot, rather than have it bang around & continually shake the wind out of the sail. I didn't use the turning block, just a padeye & cleat, like so;

That is an old photo, the lines are wrong. It should be a continuous line. Start with a deadend at one padeye, out to rotator, back to same side cleat, then around behind mast to opposite cleat, over to rotator, then back to opposite padeye. That gives 2:1, using a single line.

QuoteThat leaves the mast base and ball to buy so not quite as bad.

Reference above photo. If you have the small ball/DS rod, you also have a smaller V strap, along with the pad the DS rod sits in. IIRC, from an old 5.2, the smaller rod ends with a "pin" that goes into a hole in the smaller V strap, & is held by a screw.
If you elect to build a DS rod, you will probably not have success trying to turn a Harbour Freight die down that rod. Get a friendly machine shop to cut them, they will most likely do it on a lathe. There is just to much material to cut using a plain jane die. When my neighbour cut mine he said he turned the blank rod down by .001 first, it makes for easier threading of nuts.
I have a couple extra V straps & DS pad. You will have to drill a larger diameter holes for the new rod,(try to use a drill press, otherwise you have zero chance of perfect alignment of the holes) & will also need the compression tube that goes inside the beam, shown here;

Your new mast base will look like this. The big difference, besides being "captive", is you MUST rotate the mast 90*, & keep it that way while you raise or lower the mast. From the photo you can see what will happen if you drop the stick, without rotating it...you get to buy a new DS rod, & probably a another mast base.

Nacra hid serial #'s all over the place. Some were stamped in, some hand carved, some 5.0 buried them under the rear beam. The only Nacra 36 I have seen had it finely engraved on an SS plate.
Here is a thread on the subject.
http://www.thebeachcats.c…nc=viewtopic&topic=14494
Try to find that #, I have seen several '83's, none had the centre bar, just the 1/2 moon chocks. I've never heard of them breaking, & those boats are now 30 yrs old. I'm thinking a PO bent a beam & changed it to beams from an early 5.2, which used a centre bar.

Edited by Edchris177 on Oct 30, 2014 - 05:11 PM.

--
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
--
mhirte

Rank: Lubber

Registered: Sep 09, 2013

Last visit: Jun 01, 2022

Posts: 26
Posted: Oct 30, 2014 - 02:28 PM

Jeff O, It sure seems like those cross beams must have come off a different boat. Maybe somebody picked them up cheap and they were in better shape than the originals. I like Ed's idea (as usual) of adding a mast rotator for calm wind conditions. I will differ with him on the idea that you can't enlarge the mast rod hole without a drill press. I used the advice of Nacraflyer to use a step drill to enlarge the holes, and by means of a right angle drill attachment (about $10 from Milwaukee) was able to do this on the beach. I see the straps on your tramp are long gone. Those are too close to the edge of the boat to be useful for me. Maybe the center post is acting in this capacity with the anti-slip tape on it.

--
Mark Hirte
Nacra 5.0 1983 - (1st cat)
Deerfield, Il
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pbegle

Rank: Mate

Registered: Mar 12, 2003

Last visit: Feb 19, 2021

Posts: 879
Posted: Nov 06, 2014 - 07:39 AM

Jeff, call or email me as I just picked up a parts 5.0. Pete
ohmsj

Rank: Mate

Registered: May 07, 2004

Last visit: Nov 14, 2019

Posts: 141
Posted: Nov 06, 2014 - 09:51 PM

Pete, good to know, does it have the new style 1-1/2" ball and 9/16 rod?
did you buy the 5.0 with the blue strips that was in Santee or where evey I was?
jeffo

--
Jeff O
N5.0
solcat 18(sold),
N5.2,
H16
Camarillo CA
--
pbegle

Rank: Mate

Registered: Mar 12, 2003

Last visit: Feb 19, 2021

Posts: 879
Posted: Nov 06, 2014 - 10:49 PM

Picking it up tomorrow. Have to bring a trailer down. I think it was the old ball. Will let you know. Pete