Naumacos Racing Rib 25

[fede]

Hi everyone, I'm new to the forum,I'm posting a double here since the same thread is also posted in "rib racing",hope this is ok for admins!

< Edit: It wouldn't normally be OK, but I'll let it go this time! JK >

I'd like to introduce you to the new 25 Naumacos Racing Rib, this is a Rib that's born with a 100 % racing pedigree,with no leasure compromise.
A sport leasure version will probably be out soon but it will be quiet extreme as well and for those who like to go fast.
The Rib was commissioned by an italian endurance team and it took 8 months from project start to launch that took place on june 16th on the como lake.
The rib reached 70 knots with a mercruiser 454 at 5200 rpm ,the engine has still 800 rpm to give but the prop now is too deep in the water and we have to raise the leg to let the engine and prop rotate at a racing pace.
I'm shure we will be able to reach 75 knots once everything will be set up correctly.
ANy comment,suggestion or critique will be wellcome!

[J S]

I want one

Very nice looking boat

James

[codprawn]

Looks stunning - hull looks pretty familiar.......

[Johnwin]

The tricky devils have splashed a leeway

[fede]

Originally Posted by Johnwin

The tricky devils have splashed a leeway

"hull looks pretty familiar......"

I'm really sorry about this kind of comments,I've been really working hard for months, day and night,and came up with a hull that is for shure not unique but has it's own distinctive character.
Just to start the hull is 1.9 mtrs wide and 7.2 long, which I'm pretty shure are very different measures from what it's usually found around.
2) if the hull has something in common with other hullls it has to do with some 70's boats made by Levi, you guys might better look into some motorboating history books,the hull is a moderate delta but of course probably none of you talking about familiar feelings and splashing knows what I?m talking about.
None today is building Delta's hull because they are hulls intended for pure speed they were quiet popular in the 70's in my country Italy.
Max beam is at transom and this is intended to support a lot of weight in the back of the boat this boat weight is 1300 kg and 700 are in the aft portion.
The V at the Bow is very extreme being around 50 deg. 60 at the last station (if you know what a station is)
The deadrise is extremely variable from 18 deg to more than 55,again very few are using this kind of dimensions on hulls today,ask leeway ,I see they post on this web site!!
If anyone is interested in seeing the original lines plan I can email it ,I will not post it here for obvious reasons.
Plus you can see the entire mould construction on my web site @ http://www.naumacosdesign.it/25%20ri...pics%20eng.htm
All the mould have been laser cut from 3D files using the latest technologies.

Hull is attached in picture, if you or anyone else does recognize his/her hull please let me know...I doubt.
A lot of passion,sacrifice and thinking has gone into this boat,I've always hated splashers, so please, before you offend and hurt feelings think to 3 and be shure you know what you are talking about!!!!

[Johnwin]

"before you offend and hurt feelings"

No offence intended, purely a light hearted remark laced with irony.
It is clearly a great looking boat keep up the good work.

[fede]

It's ok John,never mind,it's just that too much passion and work went into this thing my boats are the main reason to wake up at morning,and sometimes not to go to sleep at night...

[John Kennett]

Originally Posted by fede

Plus you can see the entire mould construction on my web site @ http://www.naumacosdesign.it/25%20ri...pics%20eng.htm
All the mould have been laser cut from 3D files using the latest technologies.

. . . and that's the sort of response that sorts the real designers from the splashers.

It looks from those pictures that the mould is made directly from the laser cut profiles without using a plug. Is that right?

Nice looking boat by the way!

John

[codprawn]

Originally Posted by fede

It's ok John,never mind,it's just that too much passion and work went into this thing my boats are the main reason to wake up at morning,and sometimes not to go to sleep at night...

Don't worry the dig was NOT aimed at you!!! As I have stated many times on here it is very hard to come up with something truly new - stepped hulls for example have been out for at least 80 years.

After Mr Fuller kindly pointed out I understand what a true splash is - for example where someone makes a direct copy off another hull - yours clearly isn't!!!

It IS a stunning looking boat and the construction looks great - also your English on the website is damned good as well.

Interesting to see you have gone down the inboard route - most people seem to use outboards on similar boats - any reason why?

[codprawn]

It is also interesting to see a racing RIB with an upturned nose - should be less prone to stuffing than some of the others out there.

[fede]

Hi guys,of course, I'm not the one who pretend to come up with something totally new,many people think that the monohull limit has been reached and I'm of the same opinion,there is no reason to go wild with hull forms unless you have gone throug basin tests etc.
I was going to put steps under this hull,following the current trend on sport ribs,but then decided to go the opposite direction,moderate deadrise without steps.
I wanted to work on stability more than on top speed,all the small boats I have seen with steps behaved very unstable.
I would like to see this thing running with a couple of 225/250 outboard,the inboard is a driver's coice,and I like it,if you could hear the SOUND of this animal you'd understand!! the exhaust are open and unsilenced the entire lake knows when we are out for trials eheh,nothing better than a V8 scream for me.

Plus with the same power you have just one leg down = less resistence,of course you also have downs = single prop torque and instability caused by this.

The nose isn't really that upturned, as I mentioned the weight has been kept all the way back and the boat is very inclined back.

And yes,we used the laser cut method to skeep the plug,the mould has been built directly from the 3D files using a method developed by my friends at www.3dwmoulds.com this way you can come up with a fully frp navigating prototype.

[John Kennett]

Originally Posted by fede

And yes,we used the laser cut method to skeep the plug,the mould has been built directly from the 3D files using a method developed by my friends at www.3dwmoulds.com this way you can come up with a fully frp navigating prototype.

Would you use this mould for a production run, or do you then need to make a new mould from the prototype hull?

John

[Jonny Fuller]

Bravo!!

Have you experimented with, and without the pad keel?

Am I to take it it's loosely based on the Delta 25 then? nice boats! there are 3 or 4 over here still in service. Levi designed some lovely looking boats.

I'd like to lay my hands on his two books, but they are becoming hard to find.

Don't remember them having the flat pad keel though, more of a rounded form.

Which Merc 454 are you running? (how many hp)

[Dirk Diggler]

Originally Posted by fede

Plus you can see the entire mould construction on my web site

Superb set of photo's, Athough I'm sure that any builder/designer who was proud of their work would be able to show photo's from the beginning of plugmaking, through to the end result.

[Matt]

I like it. Almost looks like a baby FB techno 40.

[fede]

For John Kennet : My Idea is to use this mould for a couple of other hulls and after all the modifications are done (I'd like to try with longer outer strakes and some negative angle at the chine aft) and the first leasure prototype is done make the official moulds.

For Jonny Fuller: Thanks!! Renato Levi,Fabio Buzzi and Tullio Abbate are my reference as far as powerboating is concerned,there is a big tradition on lake como for fast boats,Tullio is a dear friend too,I have both Levi books of course!! and learned a lot from there,you can purchase them directly from Renato's son, Martin, www.leviboats.com there is no one particular inspirational Levi boat,but I find the Delta concept very intersting and for Racing Boats,nobody is using it today and I still have to figure why...probably I'll find out myself soon!!
I'd like to try without or with less pad and see how it behaves...I have to figure out a way that doesn't involve drilling holes in the hull bottom.
Levi didn't used much pad in his boats.

For Dirk: maybe there is something I do not get in your words,No plug has ever been made for this hull, instead of the plug we made a direct laser cut mould to save money and time,I have pics that go from 1:6 scale model making and test to final RIB launch, if you want to see them I can zip and email them to you.
Attached a couple of pics of the selfpropelled model I used to test the Hull behaviour.
And by the way...you can see more building pics here: http://www.boatdesign.net/gallery/sh...00/ppuser/1683
page 1-2-3

[fede]

Jonny,we are not shure of how much power the engine delivers since we never bench tested it,the carb is a demon,the cam has been replaced,an electric fuel pump has been added and don't know what else has been changed, I think the engine should deliver around 450 hp,and can get up to 5900 6000 rpm next season a 502 will take the place of the 454.

[slimtim]

seen those mould pics on boatdesign.net i think?

Am I right in saying (without reading this thread in detail) that you made the mould straight away without a plug? If so, how did you get the smooth finish? What is the final coat on the mould surface?

Great looking project...one day I'll find the time and money to do the same!

[fede]

Yes ,my gallery on boatdesign.net is this http://www.boatdesign.net/gallery/s...500/ppuser/1683
Yes we made a direct mould without the plug.
First,all stations and "spacers" where laser cut from ply wood, the whole structure is like a lego and can be put toghether in a day by a single person.
Then,battens are layed down to form the "net" that will support the panels.
Panels are laser precut from 6 mm Mahogany they are stapled and glued with epoxy resin.
Aftre this we gave the panels a sanded,then a 300 gr + epoxy for 2 times.
After this we sanded and then spray filler,sanding,spray filler sanding,spray filler sanding up to 1000 grit paper and the job is done.

[kitten]

Nice Job.

(edited cause I can't spell nice)