Hi
Yeah, i will change my plans. Will do a regular cockpit, and mast to the bottom, with a mast ram.
Snow has hit Denmark so plenty of time to spend in front of the computer, fixing it all again. Will maintain a bulkhead construction, I feel this is the strongest and most durrable solution, allowing higher rig tension (I think :D)
Over and out
/Anders
Bit of a night owl eh!..
Do not be too disheartened. It seems the latest rules have been massaged a little to accommodate the existing fleet and they are scared a fresh challenger will burst the bubble.
It’s the Cup, be it big or small, the same intentions run true… Keep it at any cost.
If your quick, be damn sure you are clean. Rule #1;-)
Hi Anders,
the main reasons for Italian IACC 120 rule changes is that ClaudioV new AC120 design was causing concern in Italy. The outcome of the new rules is that ClaudioV new design is now outside the new rules, however the boat he has under construction is exempt !..as it was under construction under old rule Ver 1.5
I can’t quite work out why one boat is exempt and how the same design is not but I really appreciate that he can race with us, as I really like to see how how this new boat performs.
What I want to say Anders, as your construction started well before the new rules, you will also be exempt under the new “Italian” rules also with inclusion of this new rule B.1.2 which saved ClaudioV new boat under construction.
Boat Eligibility
B.1.2 Every boats made/in construction before these rules (following R.1.5 and previous) will be already in rule.
However this new rule also brought up the LWL debacle as the previous rule Ver 1.5 the max LWL measurement was 1030m. BUT in the Italian rule version it said that water tension (meniscus) was included in the LWL measurement; however, the English version 1.5 of the rules had no reference to water tension.
I was stirring the pot about how no RC class in the world measures meniscus in LWL measurement. Then in a strange twist there were rule change suggestions that wanted to increase LWL from 1030 to 1040 mm (including meniscus) another 10 mm 
This was the hammer that made me very suspicious that something was going on to protect existing boats that were outside Ver 1.5 rules and stirred up a hornets’ nest. The outcome final is the following is a summary of changes from rule 1.5 to new rules version 2.0
C.3.1 DIMENSIONS
[i]With the Boat floating in fresh waters :
LOA (with soft bumper included) 1150 mm to 1200 (+/ - 10mm)
LWL Up to a maximum of 1000 mm (+/- 3%)
Max Beam: 290 mm Min Beam: 165 mm
The official measuring for the boat is floated in fresh water, ready to sail, with one elastic around the bow and one elastic around the stern; the elastics are shifted to the point where they touch the water. At this point the boat is grounded in a template of 1030 mm and the distance between the elastics should be equal to or less than 1030 mm. If a boat is heavier than 4500 g, during the official measuring the boat will use a lighter bulb so that the boat weights 4500 g: if it falls within the waterline length 1030 mm, the boat is in good standing and in racing it will use its original bulb heavier.[/i]
The wording here is open to interpretation, but thankfully 1040 mm LWL did not make it:rolleyes:
C. 5.1 LIMITATIONS
The appendages are composed by one Fin (two, if the real ACC boat has two keels as NZL-20 for example)/Bulb assembly (two bulbs [with a total weight using two keels of 3000 g] if the real boat has two bulbs) and by one Rudder.
D.2.2 CONSTRUCTION
The construction is unrestricted except for the following:
(a) The Hull shall be a Monohull type
(b) Except for trunking for the Fin and Rudder, the hull shall not have:
(1) voids in the water plane and/or the underwater profile
(2) hollows in the plan view and/or the underwater profile that exceed 3 mm
(3) transverse hollows in the under surface of the Hull that exceed 3 mm when tested parallel to the water plane.
© the forward 10mm of the Hull shall be of elastomeric material
(d) the Hull shall have two marks at the water plane level, one in front and the other to the back. These marks are used for the LWL length measurement.
(e) The max beam must be always measured on the deck.
(f) The hull must have minimum 45 mm overhang at the bow and 65 mm at the stern measured using the elastics and template system (see point C.3.1)
(g) The bridge must be flat or curved with a maximum of 5 mm. Behind the mainmast is required a cockpit with a minimum depth of 20 mm. The line of contact between the bridge and the hull can have a round fillet of a diameter of 5 mm or it can be 45° sloped only if also present in the real boat.
(h) The width of the stern must be between 30% and 62% of the maximum beam and should not be higher than 120 mm and should not be lower than 70 mm.
A.1.1 AUTHORITY AND RESPONSIBILITY
Each Club using the AC120 Class is responsible for the assurance of this Class Rules observations. The Regional Clubs shall designate a responsible Member for this purpose. Each owner will be first of all responsible for this Class Rules observation. In case of errors of In case of errors of translation, the correct Class Rule is the Italian version.
I should point out here that these are Italian rules only and if anyone is considering class rules in their own countries I would strongly recommend that you should not follow the Italian rule word verbatim as they will lead to problems, I would recommend class should have max LWL of 1000 mm, naturally without meniscus.
Cheers Alan
Hi Alan,
allow me to include some other considerations :
Linear specification:
LOA (with soft bumper included) 1150 mm to 1200 (+/ - 10mm)
LWL Up to a maximum of 1000 mm (+/- 3%)
I do not understand “Why” a diferent tollerance for similar meausements ?
Other Rules like “M or IOM” are defining Minimum and Maximum lenght only ! Why to make life easy if you can complicate it !!
Again here :
(h) The width of the stern must be between 30% and 62% of the maximum beam and should not be higher than 120 mm and should not be lower than 70 mm.
The Rules accept all AC since 1992.
Now , if we take for instance the recents models as NZL-20 with a beam of 194mm , Black Magic with 196mm beam , America True with 185mm beam, none of these models or similar, can meet the specifications : i.e. 194 x 30% = 58.5mm , the contradictory specification call 30% or 70mm as minimum. So which of the two limits shall prevails ?
The above mentioned models do have even narrow stern because of the slope.
Further, this type of stern is hard to measure it since non reference lines are availables unless “the drawing are required” as support evidence.
Why this interest ? Probably to avoid VOR type hull, but this can be achieved by fixing only the max stern width % ! and drops the nonsenses !
Never seen on my life such contradictory definition.
No one shall certify his own model !!!
The Rules shall be keept as clear and simple as possible avoinding ambiguous interpretations.
I also do not understand the short bow overhang of 45mm see point : (f) The hull must have minimum 45 mm overhang at the bow… Why ?
since the AC100 that is 20cm shorter call for 55mm ?
I entirely agree with your last remark Alan, others Countries may feel free to create their own AC120 Rules including a lower displacement with a minimum of 4000g, in order to render the boats more performing. The deck shall be “flat” all along and cockpit shall start behind the mast as on the real AC from 1992 to 2007.
Cheers
ClaudioD
Hi
I read the thread on the IACC forum last night and this morning… A long descussion, but appart from the change in LWL I think the rest of the changes was made to secure the spirit/looks of the class.
I will make the changes in my design, I think it was making more trouble than what I could gain by increased vang power/control. So back to the drawing borad(keyboard)… I think it is a quick fix.
Could one of you give me some pointers as to how you control the mast position in the bottom of the mastbox (don’t know what to call it). I have thought of using different sized spacer blocks, or maybe just have fixed mast steps, but how do you make those steps?
/Anders
Hi Anders,
The keel mast step is same as deck step, I made block using epoxy/micro ballon mix, then using cut-off section from mast box for mould, lined inside with wax release and after it cured just drilled some holes in it, making sure the holes are big enough to allow the mast foot pin to tilt, then drop it into bottom of the mast box.
Beware that there is a heap of tension on the mast foot of coming from shrouds, backstay etc…so make sure that the area is well supported, especially if you are not using carbon hull.
Cheers Alan
Finally a little update from my side.
I have been struggling a bit to fabricate a new fin/mast box and some bulkheads, but I think I have found a fabrication method that suits me well, and now it is just full steam ahead, on the remaining internal structures. I’m using plaster molds for these rather small parts.
For the fin box I made a reversible plug for the plaster molds, in this way I could make two perfectly mirrored CF parts. When making the CF part I first applied some loaded epoxy with graphite powder (to make it black) in all the sharp edges, after that applying 5 layers of CF fiber and then in the vacuum bag. When everything is arranged in the bag, I heat it with a hairdryer. This seems to increase the viscosity and of the epoxy and make a part of this size loose about 10g. (Jim gave me that pointer at some point)
For the bulkheads I made a plug from balsa and made the plaster mold from this.
The complete center assembly (fin box and bulkheads) will be around 100g, which i think is not too bad.
Next I have to finish this center assembly, and make the hole for the fin. Also I am working on some things in the front end and the bulb is also in the making. Masts should be shipping from TD model some time next week.
Soon I will have to begin fabrication of the deck. Would it make sense to make the deck/cockpit of Glass rather than carbon. I’m thinking if Carbon would block the radio signals to the receiver? Or is it no problem at all using only carbon?
/Anders
Hi Anders, great to see you’re back into it again. 
I had the same thought about the deck and finally decided to go with the fibreglass over carbon, only through fear of losing the signal, no experience with carbon decks but did not want to risk it and end up having to put antennas above deck.
Your fin/mast box looks great ! I’ve been using TD model box fabrication and have sail plans with static CE between 36 & 43 mm from the mast and could not induce any lee helm
Following earlier discussions else where in the forum about CLR/CE coupling I ended up doing some surgery which involved moving fin aft to have CE to be positioned 0-5 mm behind the lead edge of the fin and was amazed at improved helm balance and resulting increased boat speed.
btw: my fin has CB line runs at 40% from leading edge of the fin.
My point is, the reason I moved fin was because the mast was as far forward as it could go in the mast box, just a cautionary point before you cut fin hole in the hull, check your range of CE adjustment relative to CLR against your sail plan.
Cheers Alan
Hi Alan
I actually have the CE right on the leading edge. From this position I can still move the mast 10 mm both back and forward and on top of that we can play with the tiltl angle. So hopefully it will be okay.
/Anders
I’m sure it will be
Hi
So i more or less finished the structures for the bow. For the big pointy long(ish) part I used unidirectional fibers for the outer layer, to see how it would look and behave.
My reason for doing the construction this way, was to try and increase the surface at which this structure is bonded to the hull. To hopefully make sure it goes no where…
Also got masts and spreaders from TD Model.
Next job is to bond Finn/mast box together and place it in the hull with the bulkheads.
/Anders
Hi
Time for an update from my side… It has been a while, but not due lack of progress. My hard drive decided to die, so that made it hard to post pictures etc.
I’ll start where I left off. The finn box is now bonded, It is ridiculously strong. Each half is 5 layers of carbon and the fit with the finn was a little to tight, so I have sandwiched another 3 layers on the bonding surfaces. Next time I think 3 or 4 Layers will do for the two halfs.
Next job was to work on the bulkheads. These are now adjusted and a 10mm carbon tube is put between them. This will later support the shrouds.
Also the nose section with the attachment points is ready for final bonding to the hull. I know I have plenty of attachment points, but I want to make sure I have all the options I’ll need.
Next job was a carbon part to support the main sheet post. I’m getting the hang of this vacuum stuff. I also made a small carbon part to support the backstay and blokcs for the sheeting loop. Pics will follow.
Then I made the carbon parts for the servo mount and a holder for the battery. Just made plugs in wood, wrapped them in packing tape, and cast the carbon directly on the tape. The servo mount is made from two pieces + the bat. box it was 3 parts total. Decided to go all in, and make 3 vacuum bags and link them with hoses. That way I could save allot of time, and it worked fine. It was like Christmas the next day, unwrapping all those parts. 
Finally The servo mount and bat box is bolted to each side of the finn box. This way it is possible to change the mount in case the Hitech servo should be exchanged with a RMG. Also I like the idea of something holding the finn box together mechanically.
Now I’m working/thinking about the sheet loop and making the necessary modifications to the CF parts before bonding them to the hull. Also have to do the Rudder servo mount, this will properly start tomorrow.
I’m starting to see the end of the build, and it has really boosted my motivation.
Over and out…
/Anders
Looking great Anders … looks like you will be on the water this summer, thinking again of central Euro event with few more boats now nearing completion…maybe for next season.
Cheers Alan
Hi
I am really doing some progress now, I can see the light at the end of the tunnel. (hope it is not an oncoming train)
The remaining tasks is more or less:
Attached some pictures of the deck/cockpit made this weekend.
/Anders
Hi
just a few pictures.
Status:
mast and crane is 99% done,
Working on bulb and fin now. Apparently I made the bulb a little to big. I have made two halves, but have to remove almost 150 g. from each half, that is hard work.
If I will be able to finish this weekend. I strongly would consider going to Italy for the cup. Maybe I will go anyway, Alan has offered that I could borrow one of he’s boats if I don’t finish.
Lets see, fingers crossed.
/Anders
Hi
Today, I went to the marina to make a little balance test. I made a small bracket to mount at the end of the finn so I could move the bulb back ad forth until the balance seemed right. Raced back to fix the bulb to the finn. Didn’t quite finish, but will for sure tomorrow.
Planing to bond the deck to the hull tomorrow. That leaves sails, remaining rigging and maybe a little paint for Sunday. If everything goes smooth, I should be able to sail Monday after work. Fingers crossed.
/Anders
Hi,
I’m happy to announce my boat is finally ready to sail!
Last night we finished the last remaining issues. Unfortunetly there was no more daylight, so the launch will be next weekend.
Hopefulley my dad will also have his boat ready, so we will do two boat sailing next weekend.
The only thing missing at at the moment is the final paint job. Had troubles when painting the finn/bulb and rudder. Must have mixed some paint types as the paint bubbled off and cracked as i applied the clear coat. But only in certain areas. Very stange… I hope to get a motivation boost from sailing the boat, so I can redo the finn paint job, and get cracking at the hull decorations.
Will be back with pictures and video next week after the launch. ¨
/Anders
Congratulations Anders she looks great …even naked
Wishing you a successful launch and looking forward to some pics !
Congratulations!!! Good job!
So… She’s taken her first sail.
Everything went well. Only the top of the main was not happy to flip over. We didn’t have much wind, don’t know if that is the problem. Maybe the sail material is too stiff. It might be a combination of things.
Was too busy sailing so almost forgot to take pictures. But did manage to document a little, with my dad at the helm.
See the video, and pics.
Any suggestions as how to solve the main flipping issue?
/Anders