Your considerations are corrects.
Being a design prototype various aspect are considered :
1st - to demonstrate the design soundness and as soon as possible since tests are programmed for next august.
2nd - to introduce as much as possible new constructions solutions as such that if “something go wrong”, I still have margins for recovery.
3rd - being a prototype, there is no need for the time being to think in terms of female mold.
4th - if the results in the water with comparatives test with class M and AC120 are the expected ones , then will arrive the time to consider two aspects, confirm the constructional method (less and less probable since too many difficulties are met) and making female molds and hence with new plugs.
For most modelers, that would like to build one, the classic constructional method will be the right choice unless someone like to make his life more complicated ! hehe !!
Today, after 15,hours, of an easy removal of the laminated deck, I found a strange appearance of the plug packing tape with here and there various creases .
What happen I do not knows, further removing locally the tape, I found adhesive residues sticking to the wood surface and removed with tissue and acetone !
This was a new tape roll and probably the polymerization developed temperature was acting on the tape adhesive generating the problem !!! see pictures.
btw the actual deck weight is 61g only, therefore 5g less then nominally expected !!
The deck laminate is very flexible, better wait some days.
Not excluded to double the internal surface with foam ribbons, this should adds some 12-15g , but a female mould is necessary as rigid support !
The only time I’ve seen creasing like that was when I was experimenting with polyester resin - I can only assume (in my case) that the styrene solvent reacts with the tape facing & adhesive compound. In your case I can only think that it’s down to the brand of tape and it’s chemical composition.
Regarding the 123 deck, a 5g saving on something projected to weigh approximately 66g is obviously a useful saving. I’m always amazed how structures stiffen as the polymerisation process completes, albeit at a slower rate. When my Enterprise hull first came off the mold I was convinced it was going to need multiple full bulkheads just to support itself, never mind carrying the rig loads etc. A week later (with sufficient temps) it was a completely different story.
I think me too that is due to the packing tape brand although was appearing to be similar to the old one.
Chemistry affair !!!
The gain in weight is only relative, since the cockpit floor is not yet reconstructed and the hatch is still not included .
BTW, the hatch deposited on the deck plug was enormous and not nice to see and this because is too high. I shall make another one much lower in size from 30mm down to 20-22mm.
Cheers
ClaudioD
Interesting phenomenon with packing tape on the wooden plug, I’ve seen it happen when Rh changes very quickly going from very dry atmospheric to topical rain conditions (living in Thailand) where wooden doors wood swell 5-10mm. Looks like you have the opposite i [/i]…did Rh decrease (became dryer quickly) since tape was applied to the plug ?
I’d guess that if it were a humidity issue then glassing the plug would have been beneficial - it’ll be interesting to see what Claudio comes back with.
Row
Claudio,
Regarding the old hatch plug, it does look rather dreadful on the new deck. Instead of shaping a new one with a lower overall height would it be possible to work with what you’ve already got, ie remove material from the bottom face? Obviously this would also reduce the footprint of the plug but I still think it may be worth experimenting with. Row
Hi Alan and Row,
The humidity was the one of my flat around 50% since laminating in my lab.
I strongly suspect the adhesive of the tape. When started removing it , some time only the film was coming away while the adhesive was still sticking to the wood as observable on previous pics.
Probably a painted wood, would have behave differently !
Yes Row, I cut one foam bloc and then I started reducing the size of the existing ones.
I went to pick up the drawings of the Southern Wind yachts and reduced all to the 123 length.
The hatch eight from the mast step vary from 13 mm to 17mm.
My hatches were of 29/33mm !!
Actually are reduced in eight to 22mm and is not enough !
see pictures below
Finally I recovered the Roof from the first deck plug and, all in all for the time being, is still the best in terms of shape and proportions.
Actually is under reconstruction of the footprint and adapted to the new deck form. This plug will be used to laminate a separated roof and the roof extensions.
Time to make the reinforcements. I use the 2mm -4 plies plywood available at home . I very strong and non need for additional cover lamination.
btw, preparing a false deck to use as working support for the Roof, this time not crease found, while the tape adhesive residues are still sticking to the wood and, imo, this is normal due to the wood porosity. It should not happen with a painted surface.
ClaudioD
been away and couldn’t wait to see the progress you made. re the sticky packing tape, I’ve had this problem (adhesive remaining on the surface after peeling the tape out) with some packing tape rolls, if I left the tape too long on the stuff I was taping, and also sometimes when I was collecting my boat from the storage shed after the winter. So it looks that change in temperature, sun & probably UV and some poor quality tape have been the reason for this - never had this problem when using quality packing tape and more often but not always with cheap ones. Not sure if this will help - just sharing my experience with the same problem on this.
Your deck/roof circumvolutions Claudio make us see the virtue of a flat deck
Yet, I still believe that you are making a great contribution to the hobby by making us think about the stylish concern in the building process. I always envisioned my RC boat to sit in my living room or office, instead of in my shed. Inspired by this picture.
the roof is part of the classic layout of large yachts without forgetting, nevertheless, that my Dragon , a daily racing sailboat, of 8.90mt , is also equipped with one roof very similar to the one I made so far.
Since the begin of this project, my focus guideline was the Maxi Yachts and the modern evolutions offered by the Wally, Leopard, Southern Wind, Nautor Swans, etc., were also part of the my design concept.
The RC model shall be anyhow a very performing model with a touch of realism !
The Maxi Yachts are not only for race, mainly for leisure of rich people and as such are “dream yachts”.
I told my self why do not transfer part of the “dream” into an RC Model ?
Since the last mono-hulls of the America Cup are gone probably for ever, they do not have anymore the same “appeal” of few years ago.
I would actually prefer, in this case, to go for the old AC like the 12Metres because of the history and the charms they are suggesting, but it is not the case for this project that recall, anyhow, the features of the last AC Sail Plans.
If I manage to get a nice looking model I will be very happy.
This tread is showing also all the tribulations encountered for the first prototype.
Actually I believe to have found the right way to go ahead.
Certainly to demonstrate the performances only, a flat deck was the easiest solution !
I think you found your problem there alright ! I find not easy to get a good quality packing tape as there is so many variation around - as much as possible I try to get 3M product when I can as I find them good (recently done up the kids room and use their masking tape instead of the cheaper version and you pay for what you get with them it was good stuff ;-).
it’s great to see your building methods they’re inspiring ! and as I said before pictures say more than words and yours are great support to your text and to see how you do it.
I like taking pictures !! hehe!! It help a lot also to me !
To reduce problems with packing tape, I painted the roof …
The time is arrived to pulls some data out, particularly the budget. There is an Updating !
In the, what I call “worst case” with HS725BB heavy winch and 3 dry heavy cells (6v.), I still have some margin to take care about deck bonding , fairleads, cockpit side walls and jib anchor points. Roof is compensated by similar size opening in the deck.
Is not a peaceful situation, but feasible.
For the final setting, the 4000g-4100g overall, is still the aim !
Stripes bonding to the New deck is completed.
Actually, for economic reasons, I decided to use an available old winch the HS-725BB. Is heavy and probably not powerful enough to drive 76/76dm² of sail, but good for initial testing !
By doing that, it is necessary to modify the internal layout and I found that the accessibility, via the actual roof, to the winch is marginal in case would be necessary to dismount the servo. I’m considering other options with central servo mount.
ClaudioD
PS:
I went measuring the Hull/Deck weight differences with old and new deck. The measuring include the wood internal reinforcements, the integrated Fin Box and Rudder Trunk.
Surprise !
the actual difference is only 35g, while on the new deck is still missing the Roof and Cockpit .
Taking into account that the roof deck cutout opening will compensate almost for new roof and the cutout of the cockpit floor will compensate almost the new cockpit !, at the end the difference will be only 12g or even less !!!
Not only, for the old deck I used 2 x 105g/m² while for the new deck I used 1x105 + 1x 80g/m² !!!
Finally all that work was not really paying in terms of weight and solidity !!!
Start integration of various internal supports and trimming for alignments of trunk, fin, mast.
For that purpose I have inserted carbon tubes of various diameters. The 'central one is representing the fin and it is equipped with lead ball and fine string. the Mast and Trunk are then aligned against the ‘fin’ one.
I have also defined the Servo’s diagram with the use of the Hitec winch.
ClaudioD
Today was dedicated to the most delicate operation of the entire construction that consist on the primary alignment of the mast with the hull. For better bonding I used the normal epoxy resin instead of the Z-Poxy of 30’.
Hope no earthquakes will disturb the setting in the next 5-6 hours !!!
Some pictures :
My PC Screen is the place where everything started !!!
ClaudioD
Some further progress.
The bench alignments are OK.
Today was the time for the other supports installation that do not concern the alignments.
In parallel I worked around the New Deck and Roof. The actual weight is 91g but still missing the cockpit floor for about 22g.
Expected deck final weight before bonding 113g +/-3 to be compared with the first integral deck of 120g, sturdy then this new one !.
This experience is suggesting that the integral deck is better. I shall design a better lamination method for the next time.
ClaudioD
In picture 5 there’s what appears to be a rectangular section of ply bonded to the bottom of the hull (below the aft sail winch cross member), just wondered what it was for? Also, where the shroud plates will be bonded/bolted into place, do you intend to introduce some diagonals to help take the rigging loads to the base of the fin box?
