Hi Claudio, fantastic progress and brilliant explanations - some I use for the build of my mini40 - very inspiring !
few questions if I may:
On the pictures it looks like you sprayed it on - I may have missed it if on previous thread but what kind of paint are you using ?
did you add a layer of laquer to finish off ?
on your 3rd picture it shows the hull in white - did you apply a coat of filler and that you sanded down to have a perfect finish ?
Merci bien
Gilbert
Red hull & white deck looks very sharp - excellent! Or do you intend to play around with deck colours too? Looking at your pictures I have to ask whether or not you sprayed outside - if I tried that here it would be covered in flies & other nasty little bugs!
Just one request (at the moment!) could you post a close up picture of your eye bolts coming through the deck? From your pics I can just make out some sort of flange sitting on the deck to help seal the bolts and wondered what it was/how it was attached. Also, I note in your last budget comments that titanium dioxide was mixed with the epoxy for bonding - was there any particular reason for that?
Incredible work as usual!! Looking forward to seeing her get wet…
Regards,
Row
Hi Sylvain,
only one backstay and only one anchor point in the middle of the stern with short brass ribbon.
About mast stability I will see once in the water. Two spreads level are supposed to maintain lateral stability and the turned backward should help longitudinal stability as well.
There in no complexity for reinforcements, the mast is very simple.
Cheers
ClaudioD
Hi Row,
according to what written before, the Roof will be Red, while the fin, rudder and bulb will stay white for the moment.
Yes I sprayed outside on the balcony with 27°C and almost no wind. Fortunately no flies, but before starting I sprayed a lot of water on the floor and in the air and on the ‘dry greens’ and bushes. This allow to drop on the floor all the air dust.
The Eye-bolts are the one seen above before integration. The circular flange is simply a brass washer that will be glued/bonded to ensure coverage of the holes and providing hermetic seals.
Titanium oxide is the only additive that I have available now, since silica powder and micro balloons are finish. This powder is rather heavy compared with micro balloons or silica and contributed quite a lot to the hull weight also because I exceeded with the applications. It provide nevertheless a very strong bond.
Regards
ClaudioD
Hi Gilbert,
I used spray can paint used generally for car body that can be found in the special store for car accessory, tires, etc. Is an Acrylic paint. Very good quality and good coverage.
The hull was white because of the undercoat, the same used for the deck that is still white.
Cheers
ClaudioD
I have anticipated what could be the possible monolithic support !
Fin box being a separate item .
To note that the jib anchoring is simplified and the boom will make use of a small coaxial sliding tube to allow longitudinal adjustment. Rubber grommets will retain the boom
ClaudioD
Central reinforcement looks good - similar to a ‘backbone’ - and has the advantage of tying all components together. I’m a little concerned about the jib foot adjustment - in principle it’s an excellent simple solution (adheres to Alan’s KISS method!) - but would it not limit the overall adjustability of the sail. When compared to the ‘traditional’ method you have the ability to move the whole assembly fore & aft and are also able to refine the amount of sail area fwd of it’s ‘pivot’ point, whereas with your system you only have one source of control for jib balance (forgetting important adjustments like twist control for the time being).
I guess what I’m trying to say is that although it’s a fantastic system for achieving tangible weight reductions, is it a step too far?
Regards,
Row
Edit: Many thanks for the additional photo - all is now clear to my sluggish grey matter!!
Claudio,
Dragging up the past here, but going back to post 271 and your homemade fairleads, what is the flanged end fitting from? (pic 412, mainsheet fairlead, last component on right). It looks similar to those brass pieces included with servos for sliding through the rubber mounts - are they avilable separately if that’s what they are?
Regards,
Row
My Jib boom attachment to the deck is probably 'heavy and poorly designed !
Why 3 anchors points when only one will do the job ? See previous drawing above !
Simply transferring the ‘continuous’ sliding adjustment to the boom itself within a certain limit around 2-2.5cm.
Because of that, I did what visible in the below pictures.
It consist of a sliding coaxial tube with an eye where the sheet can be attached. The slide is controlled by rubber grommets as said above.
Careful dimensioning shall allow to fix the jib boom as close as possible to the deck. I reckon a minimum distance of 5-6mm
Sorry, I do not have rubber grommets of this size at the moment.
This method may profitably replace the ‘sliding rail’ mentioned by Alan.
ClaudioD
Hi Claudio,
I like your jib boom slider but as Row pointed out if change “boom slider” position you will change two aspects 1) the pivot point and 2) gap between Jib Leech and front of the mast changing CE (affecting helm balance)
With the step-less pivot “deck slider”, you can both of these aspects change independently 1) pivot point and or 2) change the Jib leech gap to front of the mast … and then you have the best of both worlds without compromise.
On seperate subject back in post # 278, as weight saving you changed batteries from 4 x AAA to 3 x AA = 6 volts, I did not know you can get rechargeable 2 Volt AA’s only thought 1,2 V AA’s were available ?
Was thinking to help save some weight I did battery comparison and found that 1000 mah Lipo @ 58 grams to be the best with more than 10 hours sailing time between charges and 5 cell 1,2 V AA’s (6 volt) to be heaviest @ 154 grams (including case) with roughly 5 hrs sailing time, hence you can have 96 gram weight saving there, if you wish.
Cheers Alan
The Roof is Red !
ClaudioD
Hi Alan,
my budget table contained an error about 3xAA, actually updated
I have two choices 1) 4xAAA - 4.8V. and 1000mA/h for 55g , or 2) 5xAAA - 6V. 1000mA/h for 72g (see picture 426 at post 278).
For the boom adjustment I should prepare a sail’s graphic.
Cheers
ClaudioD
Hi Row, the end fitting is simply a rivet of 3mm used also on the sails. The curved surface offer less wearing to the sheet. Similarly also the fairlead’s top will employ the same rivet for the same reasons. See picture .
For the Jib boom I will prepare a sail drawing including the CE variations.
Actually on the 123 is possible to change mast position and jib boom position at the same time (obliged to avoid boom interference). It is also possible to have additional Jib boom variation to move further the CE forward among of what already possible with the mast rake.
Cheers
ClaudioD
Hi Claudio,
Using tubes on 123 vs a mast box, how is mast raking is possible, I’ve missed something somewhere ?
Cheers Alan
Sorry Alan ,
I should have used the word ‘bending’ not ‘raking’ !
Bending, is typical of the Class M mast configuration and of all real boats when the back-stay is pulled.
Raking requires the pull of the back-stay as well the ease of the fore-stay.
Bending requires only the back-stay pull.
Bending modify primarily the sail shape.
In booth case the CE position move.
You are right, with the mast-box it is possible to slide and rake the mast ‘without’ modifying the sail setting.
For the next model I will decide between mast step on deck or a mast box with/without push rod. The weight will be the main parameter.
The carbon tube mast, while considered rigid, is offering still some flexibility. see pictures
Cheers
ClaudioD
I understand Claudio thanks, with the limited bending of 12 mm tube, is another good reason to have “deck pivot” slider to give a little more CE adjustment with the Jib, but with your excellent sail making skills, I know you like to some time balance your helm using scissors 
but for those of us that cannot make sails to save our own lives 
this is not a confident option if a mistake is made.
I’ve changed all my 10 mm masts to 12 mm for extra stiffness but found one problem you should be aware of:
I use mast crane with 20 mm long “flat flang” that slides into mast head, after couple of outtings in heavy air (backstay cranked on) I saw the 12 mm carbon had spilt ! so I now mount flat flanges into 20 mm long by 10 mm O.D carbon tube and filled the void with loaded expoxy and slid this inside to 12 mm tubes to stop them splitting.
Did not help that I had one sail suit made with luff curve to match 10 mm O.D tube when changing to 12 mm required too much tension was used to match main sail luff curve (learning curve trap for me :rolleyes:)
Cheers Alan
As promised here the sail drawing when the Jib boom is sliding by 20mm :
On top of that there is also the mast tube position that can be varied by another 16mm.
Of course this is a geometrical analysis, since the real CE is generally ahead from the static one. Relatively the situation is very similar in terms of shift.
So, without pulling on the mast back-stay, the CE can move within the range of 16+13mm = 29mm.
This range is very comfortable to cope with the tuning requirements vs sail dimensions and centering.
Raking will add additional adjustment, especially backward, with very low winds helping heading up !
Further CE variations may be introduced with the back-stay, although the “bending” imply also the change of the sail form.
Having said that, as mentioned above, the Mast Box or the Mast Step on the deck will be the choice for the next model, where bending and rake could be applied !
ClaudioD
Hi Alan,
anyone can make more then reasonable sails, there is the need of some training, but for sure at the third attempt you will get what you are searching for. It will be next argument while completing the ‘hull affair’ !!
About splitting, I never got problems until now, but it is also true that I use collars every where I believe could exist some strength problems.
Now, my mast is crossed fibers type, thus very rigid and it is composed of 12mm OD for 70cm + 10mm OD for 60cm + 8mm OD for 55cm = 185 cm (penetration in the hull excluded). The top 8mm OD will be reinforced for the crane of 130mm length with additional 10mm tube collar and loaded epoxy inside. The crane will be a carbon rod (not tube) of 4mm inserted via a drilled hole.
Cheers
ClaudioD
Introduction for future discussion : (sorry is in Italian, but pictures can help to give an idea about.)
http://www.nonsolovele.com/DATECNICHE/Claudio%20Diolaiti/VELE%20FINALE%20di%20Claudio/FORMA%20PER%20VELE-2.pdf
http://www.nonsolovele.com/DATECNICHE/Claudio%20Diolaiti/VELE%20FINALE%20di%20Claudio/FORMA%20PER%20VELE-3.pdf
ClaudioD
About 123 Sails :
I do have a choice from 75dm² to 78dm².
The drawing shows some important details :
The Main profile is dictated by the Elliptical form (1/4 of ellipse).
This form is the one that, in theory, provide the best efficiency ratio. Far away from the square sails used by the AC.
The sail top produce less turbulences and air flux returns from one side to the other.
Less twisting problems.
Reducing the Main top sail area, compared with squared ones, produce a lower CE.
Gaining surface at the sail top to find better fresh airs may be interesting at 35 meters above water but very probably not at 1.5meter above water.
Lowering the Jib as much as possible to the deck, present the advantage to reduce the air return fluxes and therefore increasing aerodynamic efficiency in close hauled. This cannot be done with the Main due to Wang, although a wide boom with triangular section may improve the conditions quite a lot. Is not excluded such solution for the next model.
Shortening the Main top sail require shorter crane and therefore stronger against bending.
ClaudioD