AC100 eXtreme

Dear every one,
its a pleasure to inform you that the ac100 eXtreme Class is now fully operative, but let me explain few informations due to avoid any confusion. The AC100 Class born (with this name) one Year ago as a request from a group of Italian moddelers (coming from Rome and from the same PVC boat class). The request was delivered to ClaudioD that was very happy to design this new 1 meter American’s Cup RC boat. As long been recognized in RC-modelling, that around the world, several AC Class boats with different dimensions and characters were constructed (e.g. IACC120 mici-AC and several others), but none of the above mentioned models satisfy our request (fast, extremely manouvrable, cool shape and design). Starting from this point the first AC100 boat was designed (AC100A), suddenly followed by the B version and several others. Today the Class AC100 is still alive as demonstrated by several boats under construction and up to 4 AC100 finished in Rome. To answer a question: Is there any differences between the ORIGINAL AC100 models and the recent AC100 eXtreme? Basically NO, both are AC100 (e.g. 1000mm LOA, 850LWL, 450 DRIFT, 60dm2 Sail), but if I need to be honest some differences can be found. In regard to ours original request (fast and manouvrable), after several months of field and dynamic tests we decide to introduce few limitation in the original rulers, due to emphasize the original request. This mean that the AC100 eXtreme have a limitation in the weight of the bulb infact we setup a maximum weight DRIFT+BULB up to 2250kg. This represent a necessity to limit the total displacement of the boat and make it light and fast. If a modeller want to realize 1 meter boat with a total weight up to 4kg it is better to build a IOM. Furthermore all eXtreme AC100 are equipped with special drift. We also introduced a third set of sail and completely remove the lenght of the mast. As you can C AC100 eXtreme could be considered as an Upgrade to the original AC100 but this do not compromise the possibility to have regattas togather between AC100 and the AC100 eXtreme. Infact in our rulers (soon available in English) all the models built to date are completely included, no exceptions is required. At this point I would like to underline that a CLASS is represented by the peoples that build a boat and play togather and not by the designer of a model or few designers. Till peoples will build AC100 this class will alive and grow, and only in Italy we have up to 30 modellers working hard to build AC100, and all of them agree with our eXtreme Class rulers

Dear every one,
Yesterday 6-5-2011 at 22:00 local time (+1 GMT) we uploaded the first eXtreme project. We are sure to be able to upload a new project every 30 days.
Follow us in this new and coolest RC one meter site and be happy with us.


why you call it " ORIGINAL AC100 " since the AC100 was introduced already for the “first time” in this forum the July 16 - 2010 ? :

I think you have a problem !!
I just pickup a corner of your drawing AC100 Extreme :

summing up all the surface values indicated on the COA, I get 2606cm3 and not 2692cm3 as marked on the drawing
Further according to my calculations and assuming a LWL of 850mm, the prismatic coeficient is 2606cm3/4588cm3 = 0.568 and not 0.58 as written. and this may be a problem for medium/hight winds
The situation get worst once you calculate the loss of volume with the use of a LWL of 835mm that I extimate to be about 152cm3, derived from my calculation of the water plan surface that do not appears in the drawing - strange !!

The hull volume available for LWL of 835mm will 2606cm3 - 152cm3 = 2454cm3

If then you take this last option and you add 2454g + 342g of the appendix = 2796g and you substract the bulb of 1850g, at the end remains 946g for the total construction !

Is all that correct ?


This is to demonstrate how a new design can be introduced with a lot of publicity as to be the best so far !

Simple, you take the shadows of the well knone AC100-B as shown here : with few movies ,
you stretch them a little, one by one, orizontally and vertically and you get a perfectly matching new shadows called
AC100 Extreme !!

This how someone pretends to have made a new designs !


Hi Claudio, I agree with you 100 per cent. I built my AC100 to your original specifications and I am very happy with it. These
people with their AC100 Extreme have only copied your designs and believe they have a new “Superboat”. They surely will
not get many followers with these tactics. At least they should have been kind enough to ask you for permission. Well all
I can say is that the world is full of strange people. Regards
Norman Storer
Brevard, NC, USA

Dear every one,
it is time to reply now…
First of all I would like to apologize about the coefficient values that was wrong, as soon as possible we will upload the correct version of the numerical calculations. As a first project it, as sometimes appear present some little mistakes. Despite the numerical values the rest of the project is perfect.
But now let me introduce the falsification procedures that ClaudioD posted in the above reply.
As you can c in the image NOT MODIFIED using a graphical program but simply OVERLAPPED the two project the two boats are extremely different in lines, in desplacement and in shape.

AS you can observe the central section is more large and high, while in the mascon sector the shape of the hull is tight and lower if compared to the 100B model.
Now without showing a numerical values to demonstrate that the two boats are absolutely different also a cross-eyeds are able to c differences.
I would like to suggest to Claudio to DO NOT FALSIFY results, and as long been recognized a comparison between two object must be WITHOUT modifying the single shape as demonstrated by my overlap.

p.s. Remember that falsify the data just to support your unsupported hypotesys is ignominous

Hey You Guys - you are putting us moderators in a tough spot.

We can let this stuff go on without comment (and people will quit reading)
We can remove posts that begin/continue arguments (which will interfere with the thread)
We can close ALL AC threads to further posts (no additional posts will be allowed - threads will be locked and those interested in building/sailing/racing will be disappointed
YOU can end the hostilities between yourselves, just post the status of the project, and get some boats on the water - letting the builders select and build to which ever design they want.

From my point of view, it is up to you - if you want to have an opportunity to remain on a site and demonstrate how good a design you have - build them, race them and let results speak for themselves. I am speaking personally now …

I am not your private police, nor do I have any intention of taking sides - regardless of who is right or who is wrong, I want to enjoy discussing radio sailing, to learn, and to see/hear of new developments. I do not enjoy these on-going pi$$ing matches - so either behave like the adults you say you are, or find another forum to host your design fights. Please end the fighting now. I am thanking you in advance for your expected cooperation on this issue.

Dick Lemke
Only one of a couple moderators here —

Thks so much Dick,
I would like to inform all, specially the ones at the beginning of this wonderfull hobby, that we are writing in the AC100 eXtreme forum, a detailed guide for sailing from A to Z, applied to RC models. Despite this at the moment we dont have time to translate it into English language, but i’m sure that in the near future someone will have time to translate it into different languages.
It is my believe that the most obstacle for a new modeller is to understand the secrets of sailing. Every one know that lots of informations are available on the web and lots of books have been written, but i’m also sure that if a novice modeller have a direct guide, with the possibility to interact directly and in real time with the writers, his capacity to learn and be a great skipper will increase in time and in quality by 300%.
For this reason we are carring on this section, and as soon as possible also several diagrams and images will be posted to further increase the understanding of the text.
Hope this information could be usefull for the comunity.
Thks for attention

dear everyone, the second design ac100 eXtreme is born: here is the ac100 BRUTAL,
as soon as possible, the first model of BRUTAL will be built and tested…see you next month for another design, more traditional than BRUTAL

Dear every one,
It is a Pleasure to inform the community that the last week-end of June the AC100 RC Sailing Class was invited to partecipate at the event “Il VILLAGGIO DELLA VELA” a sort of Boat Show, with two days dedicated to the sailing at any scale from 1:1 to AC100 Scale, and to any aquatic sports. The organization is building a dedicated Stand for us, where peoples could c and touch real AC100 boats, in the 5 models available at the moment (AC100-A-B-S-Brutal-Hybrid).
In attach file you can easy find the official invitation flyer edited by the organization.

dear every one,
here is the master of the AC100 BRUTAL…all in balsa strips
next time the model sailing for test against ac100 a-b-s? i hope…more photos in (forum-scafi in costruzione)

hi all, here some photos from ac100 extreme sailing contest on villaggio della vela in bracciano lake

more photos in (forum- foto e filmati)

new ac100 eXtreme…

here two videos of last racing

more photos and videos (also the step by step contruction of china team) on

Hi, Finally good weather for sailing. Regards

new ac100 eXtreme project available…LUXURY…on

AC45 - Energy Team wins World Series in Venice - 2° Oracle Spithill - 3° Artemis :banghead:
Races without wind :sonar:
cheers, GINO

last contest of ac100 eXtreme on bracciano lake

another great day aboard ac100 eXtreme…

finally the LUXURY design…