1.5 Nacra in the making :: Catamaran Sailboats at TheBeachcats.com

1.5 Nacra in the making

revintage

Rank: Mate

Registered: Aug 13, 2017

Last visit: Nov 29, 2023

Posts: 280
Posted: Sep 06, 2023 - 06:46 PM

Edited by revintage on Sep 06, 2023 - 06:53 PM.

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Brgds
Lars

Frankentri 5.8/5.5/Inter20
Aerow trimaran foiler

https://www.facebook.com/groups/1192604934176635
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rch701

Rank: Mate

Registered: Jul 06, 2009

Last visit: Mar 28, 2024

Posts: 383
Posted: Sep 07, 2023 - 10:27 AM

I am definitely following this! I am concerned with torsional stiffness but hey, should be a good story at least.

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FYC, Nacra 5.2 "Chris's Flyer" & Nacra Playcat
Previously owned: Trac 14, H14, H16, H18, N5.0, G-cat 5.0
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revintage

Rank: Mate

Registered: Aug 13, 2017

Last visit: Nov 29, 2023

Posts: 280
Posted: Sep 07, 2023 - 05:15 PM

QuoteI am concerned with torsional stiffness.

Have taken care of that, by use of waterstays to minimize bend in the oversized beams, almost double wall thickness compared to Nacra beams. More info in my FB-group in the signature below.

Todays work in the image, cockpit floor tomorrow.

Edited by revintage on Sep 07, 2023 - 05:38 PM.

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Brgds
Lars

Frankentri 5.8/5.5/Inter20
Aerow trimaran foiler

https://www.facebook.com/groups/1192604934176635
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Andinista

Rank: Mate

Registered: Aug 18, 2003

Last visit: Dec 13, 2023

Posts: 880
Posted: Sep 08, 2023 - 10:45 AM

What's the objective, more speed? With a bigger sail or under stronger winds?
Or is it more about the process than the end result?
revintage

Rank: Mate

Registered: Aug 13, 2017

Last visit: Nov 29, 2023

Posts: 280
Posted: Sep 08, 2023 - 02:45 PM

AndinistaWhat's the objective, more speed? With a bigger sail or under stronger winds?

It is to get an all together bigger, more seaworthy boat, 5.8x4.8m. Larger rig and a lot more RM. Large enough to carry a small outborder when doing longer trips. No need for trapeze for the old man. Should be a little slower at light wind, equal when sailing with the center hull just lifting and capable of higher winds. Rudders on amas and daggerboard on center hull.
Time will tell......

Edited by revintage on Sep 08, 2023 - 02:46 PM.

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Brgds
Lars

Frankentri 5.8/5.5/Inter20
Aerow trimaran foiler

https://www.facebook.com/groups/1192604934176635
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Andinista

Rank: Mate

Registered: Aug 18, 2003

Last visit: Dec 13, 2023

Posts: 880
Posted: Sep 09, 2023 - 08:20 AM

That’s cool
So like a Cadillac. Or maybe a Chevrolet C15 :)

Edited by Andinista on Sep 09, 2023 - 08:23 AM.
revintage

Rank: Mate

Registered: Aug 13, 2017

Last visit: Nov 29, 2023

Posts: 280
Posted: Sep 09, 2023 - 09:16 AM

AndinistaThat’s cool
So like a Cadillac. Or maybe a Chevrolet C15 :)Edited by Andinista on Sep 09, 2023 - 08:23 AM.

A 250kg convertible .

Question is what to build with the remaining 5.8 hull and the F18 rig?

Edited by revintage on Sep 09, 2023 - 09:54 AM.

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Brgds
Lars

Frankentri 5.8/5.5/Inter20
Aerow trimaran foiler

https://www.facebook.com/groups/1192604934176635
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ctcataman

Rank: Mate

Registered: Nov 25, 2015

Last visit: Apr 23, 2024

Posts: 658
Posted: Sep 09, 2023 - 08:55 PM

Kudos for building this.

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John

Nacra 5.0
CT
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klozhald

Rank: Chief

Registered: Apr 19, 2011

Last visit: Dec 13, 2023

Posts: 1445
Posted: Sep 28, 2023 - 07:05 PM

revintageby use of waterstays to minimize bend in the oversized beams, almost double wall thickness compared to Nacra beams.

Wow - those beams are massive.
This is a great project Lars!

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Sheet In!
Bob
_/)_____/)_/)____/)____/)_____/)/)__________/)__
Prindle 18-2 #244 "Wakizashi"
Prindle 16 #3690 "Pegasus" Sold (sigh)
AZ Multihull Fleet 42 member
(Way) Past Commodore of Prindle Fleet 14
Arizona, USA
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revintage

Rank: Mate

Registered: Aug 13, 2017

Last visit: Nov 29, 2023

Posts: 280
Posted: Oct 01, 2023 - 05:24 PM

QuoteWow - those beams are massive.

This is the design I have choosen, note I use two shrouds/side connected to the same point as the waterstays, to make the platform as stiff as possible without loading the 5.5 hulls:

This is the inspiration for the rig, where I have marked shrouds/waterstays in red:

Edited by revintage on Oct 01, 2023 - 05:33 PM.

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Brgds
Lars

Frankentri 5.8/5.5/Inter20
Aerow trimaran foiler

https://www.facebook.com/groups/1192604934176635
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klozhald

Rank: Chief

Registered: Apr 19, 2011

Last visit: Dec 13, 2023

Posts: 1445
Posted: Oct 02, 2023 - 02:25 PM

At nearly 16 feet wide (4.8m), you are obviously planning some sort of Ackerman steering method.
Will you achieve this by bending the tubes coming from the castings to the tiller crossbar?
The Dart 18 my friend sails has this.

Edited by klozhald on Oct 02, 2023 - 01:25 PM.

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Sheet In!
Bob
_/)_____/)_/)____/)____/)_____/)/)__________/)__
Prindle 18-2 #244 "Wakizashi"
Prindle 16 #3690 "Pegasus" Sold (sigh)
AZ Multihull Fleet 42 member
(Way) Past Commodore of Prindle Fleet 14
Arizona, USA
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revintage

Rank: Mate

Registered: Aug 13, 2017

Last visit: Nov 29, 2023

Posts: 280
Posted: Oct 02, 2023 - 06:07 PM

QuoteWill you achieve this by bending the tubes coming from the castings to the tiller crossbar?

Have a pair of Marstrom Tornado rudders. Will add adapters at the tiller ends to get a toe in of 10-15 degrees.

Interesting Ackermann paper:

https://docplayer.net/442…ckermann-principles.html

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Brgds
Lars

Frankentri 5.8/5.5/Inter20
Aerow trimaran foiler

https://www.facebook.com/groups/1192604934176635
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