Hi, got an ally Marstom mast tube for free from him in the eighties when we both where active in the Tornado class. The first batch where not not legal so he told me to use it as a flagpole .

Anyway, I am planning to modify the rig on my old 5.5 using this mast and a higher mainsail.

I would really appreciate if someone had the possibility to compare an Inter/F18 mast foot to the Marstrom footprint in the pics? Hopefully I could modify the foot without to weld it. All measures in mm with width taken every 10mm.





Thanks
Lars
Sweden



Edited by revintage on Aug 13, 2017 - 12:36 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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What would make it not legal. Did they have some sort of stiffness spec back then or something?

No problem, it would anyway probably measure in as a F18 if I tried. But I am the only Nacra sailor here. As I am retired from racing since more than 30 years, my only aim is to enjoy more speed .

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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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tamumpower1

What would make it not legal. Did they have some sort of stiffness spec back then or something?

http://www.tornado-class.…rnado_2016_CR_281016.pdf
there are all sorts of rules pertaining to the mast - anyone of them could disqualify a mast from competition
and it needs to be certified

I heard that back in the Tornado aluminum mast days, you would have to get several masts and test them to find those that suited you best. Aluminum extruding at that time was not very consistent.

jack108136

I heard that back in the Tornado aluminum mast days, you would have to get several masts and test them to find those that suited you best. Aluminum extruding at that time was not very consistent.

I have heard that about stock sails back in the day (american brand)

Quote

What would make it not legal. Did they have some sort of stiffness spec back then or something?

Guys, lets stay on topic.
The Tornado was the Olympic Cat, & so very tightly controlled. Lars is not racing, doesn't care about Class Legal, he just wants to go fast.
Can someone with an Inter 18 give him a footprint of the mast base?
(Sorry Lars, the only guy I know here in Canada sold his I18)

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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,

As you say I am not racing. Retired from the Swedish Tornodo circus -86, being No2 behind unbeatable Marstrom. Sold my boat(the first Marstrom Tornado ever produced) and haven´t sailed since and bought this 5.5 when I retired from work. Just for fun!

Seems like Inter is quite obsolete nowadays. Really hope someone have a mastsection lying around. Also wonder if the first F18(02-05) used the same mast section?

Actually any base with the rotation arm and downhaul in the base will do.

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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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My understanding is that the Inter 18 had a carbon mast, don't know the shape. There are several of those guys on here thou. Maybe one will step up.

The first nacra F18, pre Infusion, had the same mast extrusion as the 5.5 SL. the only real difference was the boom fittings or lack of and the rotation controls. Same step and base, same halyard hook, same spreaders, and minor differences in diamonds, I even use the same diamond wire tension on the 5.5 SL and F18 and same spreader rake. No built in cunninghame. Same base as 5.0, 5.5, 5.7, 5.8, and 6.0. probably the same as all 70, 80 and 1990 nacra's.

The Infusion, is an aluminum stick with different shape and has the base like you picture above with the built in cunningham.

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Ron
Nacra F18
Reservoir Sailing Assn.
Brandon, Mississippi
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They made the Nacra Infusion base style for the carbon masts (Inter 20 specifically, I believe the Inter 18 is the same stick but shorter, but I could be wrong), however they are no longer produced as best I can tell. This is the only part available for those particular masts: https://www.murrays.com/product/56-6605car/

It will be some time, next week at the earliest, before I can check the Infusion mast base dimensions for you. I may have them archived somewhere more accessible but if not I have to pull them off a mast. Unfortunately I can't do that for the Inter 20 sticks.

Lars,

Like Ron and Sam said, your 5.5 mast base should be the same as all Nacra carbon mast bases. Newer AL extrusions from Nacra are wing mast profiles. You have a 5.5 base. Have you tried it on the Tornado mast yet? I'm pretty sure it will fit. I have some bases I can measure but now is not a good time for me.

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Philip
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Hi Ron, Sam and Philip,

Thanks for your info. The 5.5 base will surely fit with minimal modification. But its the built in cunningham and the rotation I am after . So if all profiles are the same as 5.5 until the newer wingmasts, there should be no problem.

Actually the base in the pic is said to be used for Inter/F18, not Infusion.

"Nacra F18 Inter Mast Feet
Model NAC30177
Condition New
Nacra F18 Inter Mast Feet"

I guess Inter might have been around both with ally and carbon mast. The base in the pic is probably for the carbon version.

As I will strip my 5.5 mast and move all parts to the Marstrom tube, I can as well move the base too. The forward pointing rotation arm can be mounted the same way but rearwards.

Will then use it with a used 02-05 mainsail and an Infusion jib.

I thought the Inter 18 was predecessor of the 02-05 F18, then followed by Infusion F18.

Will do a course check tomorrow without removing the 5.5 base.

Brgds
Lars



Edited by revintage on Aug 19, 2017 - 12:31 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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Checked the outside width and length of the 5.5 mast profile. At 75x104mm it will be a quick fix to adopt the 5.5 base to the Marstrom profile that is 75x114 ex. luff track.

Think I will stick to that and forget about the Inter/F18 base.

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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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