Continuing with the fin box installation and bonding including the alignment using the fin/bulb as centering balance on 2 axis.
Refreshing paintings with spray can.
Cheers
Claudio
jumping back !
some shots about Trap-65 once in the bathtumb equipped with the newest CD-RIG !
Cheers
Claudio
being the bathtumb full of water I toke this opportunity to check the Fuxia-65 still under assembly/construction the floating lines by loading the foreseen loads. To note that the bulb was of 750g instead on the Trap-65 above was of 650g. On the pic where the hull is tilted about at 33° it is possible to see that the upper rudder blade will be out of water and I fear some loss of efficiency, on the others hands, there no intention at all to istall two rudders !
Cheers
Claudio
Hi Claudio
bow distance to water looks almost perfect. The bow on mine sits a bit higher, but when heeled over, it is just barely above the water and when a bit of a wind gust hits, the bow drops down and is just below the water. I feel that this is optimum, since the bow is above in light winds, and doesn’t go too deep in stronger winds. Downwind I have not sailed yet in strong winds, so cannot say if it has tendency to pitchpole.
Regards, Dick
Claudio,
How have you tilted 33° ? It looks like the keel is resting on the bottom.
If this is the case then the hull is not taking the full weight of the keel. You are also missing some of the weight of the fiinished boat, and are also missing the downforce of the heeled sail. The forward motion will also create the wave pattern that will “sink” the hull lower in the water.
The heeled boat is going to float considerably lower than your static test shows.
Jon
Hi Dick,
as you have observed, I’m working almost in parallel with Trap-65 and Fuxia-65.
If you are referring to the Trap-65 you are right, the boat is complete, only the power switch was in “off” position !
I hope soon to verify the CD-RIG in the water pond. I’m less sure for the Fuxia-65, even most of the volume is sitting in the second half of the hull .
Thanks for your observations, hope will be ok also on the water.
Cheers
Hi Jon,
I appreciate your remarks because it will be give me the opportunity to explain more.
Yes indeed, your observations are right, the bulb was touching the bottom of the bath and, as you says, not all the weigths were involved.
The missing parts, about 80g, are essentially the various internal supports and of course the deck (25g), while the Rig was represented by a second 6V battery (65g), in front of the fin box, On the other hands, the fin / bulb was of 816g instead of 711g as on the Trap-65 and, under this condition, was possible to observe, once right , the water line position. Therefore, all in all , the situation should be close enough to the final
The pictures of the Fuxia-65 were made at this stage of construction, profiting of the water in the bathtumb, as said before.
I was simply curious to verify a couple of things :
- the shape of the immersed Water Plan as I did with the AC33.
I was interested to see if this hull was presenting a similar simmetry and verify that stern corner was not going drammatically under water since I was introducing a slope in the back part of the hull and - secondly, most important, I was concerned with the amount of rudder blade surface that was protruding out of the water when the boat is tilted.
This second aspect may actually suggest to make another rudder with different shape, narrow and deeper or vintage style , narrow close to the hull and wider at the other extreme.
Obviously, all that will be verified again once the boat will be completed as I did for the Trap-65 or directly in the real water side.
The actual weight is 1050g + 85g (rig & deck) = 1135g, therefore some 40g/50g above design weight and 0.8mm deeper in the water.
Thanks again for your remarks .
Cheers
Claudio
Hi Claudio,
On Fluxia I hope the wooden beam towards the stern is a temporary one and will be removed before the deck goes on. It seems (from the photo above) to be distorting the starboard sheer line creating a hard corner in the aft section.
I’m not a big fan of fuchsia, but you seem to have cornered the European market in that color paint. No one will wonder whose boats these are. Best of luck with them!
It seems (from the photo above) to be distorting the starboard sheer line creating a hard corner in the aft section.
actually I believe that is an optical illusion caused by the change from a straight line to a downward angle of the sheer line to meet the lowered stern line.
Exactly, is an optical effect because, due to the slope, there is a sudden change of surface direction. This sketch will explain also to Niel that the beam is just temporary waiting for the deck coverage, unless I change my mind !
Finally ! someone telling me that he don’t like Fucsia color ! hihihi - from latin : “De gustibus et coloribus non disputandum est”
Cheers
Claudio
PS : some more views at post 75
Preparing the deck laminate .
Claudio
I stand corrected.
Is the point of the sloped after-deck to reduce weight, or just for looks? Or is it to bring the rudder linkage above deck or some other mechanical reason?
I would think that such an arrangement would see the deck-line in the aft sloped section interfere with the water and waveform when heeled over. I would also be concerned with the amount of windage Fluxia’s underbody exposes when heeled as illustrated in the heeled photographs.
I really don’t intend to put you on the defensive Claudio, but its not just the color of this boat. I hope it performs well for you but I think it has way too much surface area to be effective in light winds and shows a lot of its underside when heeled which, as you pointed out, raises a portion of the rudder out of the water creating a whole lot of drag. I don’t think that she will balance when heeled the way you expect her to, and these dynamic shifts are not worth using an extreme wedge shape to move the center of bouyancy aft. In spite of your bathtub demonstration I think Fluxia will submerge some part of her stern when heeled so you might as well bring the sloped after deck to a sharp edge with the hull and roll that sharp fold in the deck to a smooth curve.
I think you will probably be sailing the Trap-65, which is a quite nice looking if conventional hull. I see a trend toward lighter overall displacements so bringing out a design in the 900 gram range might be a good direction to explore. I think you could certainly save some weight in the hull by reducing the interior structure. Also, changing over to a balsa-core/CF sandwich material for the deck beams rather using solid material will further reduce the weight of the interior structure allowing an improved displacement/ballast ratio.
Hi Niel -
as noted before by others - there simply is no need to use carbon or sandwich materials in this class. I have a couple of hulls using only epoxy “coated” 1/16 balsa - and my own boat “Morning WOOD” is 1/20 Mahogany-Sapelle veneer. The extra expense, stiffness, and work to have a composite boat has proven to be “on par” with simple balsa-only hulls.
Of course, if one wants carbon fiber, for a reason (mine = mostly looks) as I selected some exotic veneers, by all means have at it - but it looks like many regatta results from all over (Europe, South America, etc.) seem to indicate a balsa-only boat is effective, fast and competitive as it’s much more costly step-brothers (or sisters). I have three deck beams that also make up the bulkheads in mine, and they are 1/8 inch thick balsa. The deck is to keep water out - not to stand on it, and there are some out there that simply use a mono-cote material from model aircraft building for a deck - is carbon balsa core deck beams really needed? I don’t think so (in my personal opinion).
I wanted to point out these facts so potential new RG-65 owners aren’t intiminated by the supposed “need” for carbon, Kevelar, cored hulls, etc. There are probably just as many plain old fiberglass hulls that remain competitive as well.
Cheers
Hi Niel
Fuxia-65 is just an experimental model.
Cheers
Claudio
Well Dick,
I agree with you completely. I am building up two boats concurrently just as Claudio is. One is a BlueSplash hull from Eric Rosenbaum and the other is an all-Balsa multi-chine design of my own. There are no tested RG65s in my area for me to compete with. BlueSplash is a competitive, up-to-date boat that will act as a performance benchmark for me to develop my own RG designs. It is a very pretty boat and I hope it will also spur interest in the class in the NY area. The multi-chine design is an effort to come up with a fast and easy to construct hull that also is elegant looking. I’m not a big fan of the JIF series, I think they are rather clumsy looking.
I see RG65s as bigger Footies rather than smaller 36/600s or Ms. The RG may be twice as long but it only carries a third more sail area so the loads an RG sees are probably on par with those of a Footy with a top displacement/ballast ratio. My comment to Claudio about the internal structure of his Fluxia being overbuilt was merely to point out that overbuilding seems endemic to RG construction. So much effort is put into shaving weight from the hull casting and so little attention is paid to the weight of the rest of the internal structure when consideration and the control of the combined weights of all the parts should be the focus. Looking at build logs and the weight schedules for several of the designs that are published online, shell weights of 60 to 75 grams are considered good and the hull with bow block, transom, deck beams, keel trunk, and mast tubes together weighing in at 125 to 160+ are considered normal targets. Rather than a 50%/50% shell to braced hull ratio I think a 60%/40% ratio or better is achievable with thoughtful structural layout and attention to material weights.
As to how to reduce the weight of the internal structure, well that is the area where the individual builder can get creative. I mentioned CF/Balsa core material. I make my own sheets with one panel of 1/8th Balsa sandwiched between wetted out single layers of 6oz./yrd. Carbon Fiber plain weave cloth. This sandwich is then pressed between two plywood boards (mine are faced with smooth, white formica) and clamped down to 3/32nd stops between the plywood boards. This impregnates the balsa while expelling any extra epoxy from the cloth weave. I have used this material for all sorts of structural members (including deck beams) in my 36/600s, Ms and 10 Raters. Its not hard to make and you can cut the Balsa core/CF sheet easily with a few passes of an X-Acto knife.
A friend of mine built some very light M class boats using .040 carbon rod for deck beams placed in several diagonal cross patterns. His boats had almost no flex with this layout. Smaller diameter members could be used for RGs. It is important to reinforce the inwales where the carbon rods land because they are strong and narrow and could pierce the through the inwhale. A good idea as well is to glue in place little “pockets” to keep the beams from moving while gluing them in place or breaking loose under load (there is very little surface area on the ends of carbon rods). My friend used little squares of 1/32nd ply with a hole slightly larger than the carbon rod to anchor the rod ends in place. My friend tied the cross beams together at their intersections with a couple of strands of CF and used Ca to seal the joint.
For my two hulls I am using a 1/64th ply/Balsa core sandwich for the beams and internal structure. Very light and strong. I am avoiding Carbon Fiber in these boats because I am going to fit them out with Spektra receivers and CF can shield radio signals from short antennas (there is enough interference from the reflections off the water). It is also easy to cut lengths and sand them for a precise fit without getting your hands and work area covered in slippery black dust. Very important for the kitchen table builder.
And Claudio,
I am sorry if I put you on the defensive. But I am curious, you say that Fluxia is experimental, what is it that you are hoping to find out with this experiment? Is it one aspect of performance that you are trying to emphasize with such an extreme shape or do you have several concepts that you are working on at one time here?
Niel -
thanks for the explanation and views. My comments are made with the hopes that the class will grow quickly - and be a viable class for builders who “aren’t” into composite building. The mere thought of worry about weights, composites, carbon, etc. as I mentioned can quickly turn a potential builder from the “build” call to one of purchasing a “plastic” boat of some unknown heritage. It may look good - but … [smile]. One can also purchase a Bantock RG boat, but again, it becomes a concern of available budget versus perceived performance.
While the JIF series is not the most modern of “looks” and in no way resembles the popular “du jour” skiff/ocean racer/TP52/IOM/etc. styling, it is still competitive if a person puts time into tuning and less into looks. If you recall, I chose the original JIF65 since I was building four of them for family fun and racing. To me, a boat made from 4 panels of balsa plus a deck ha great appeal. I also found that there were plenty of free designs, but unless one was willing to put in the time to build with strips, only a few hard chine boats were popular. If a builder was going to put in the time to strip build a hull, and then (perhaps) make a mold and layup other hulls, they might as well put their energy into an IOM design. The JIF was billed as a “Half-Marblehead” rather than a “2 times Footy” and with the issues the FOOTY class had about batteries and restrictions, the simple rules of the RG-65 were also very appealing. Thus I proceeded to build on Brett McCormack’s initial post that introduced me to the RG class. From there a lot of promotion and it looks like the class has taken off (a bit) in the U.S. - although I still think we need more cheerleading… but that is my opinion.
In the meantime, it would be nice to have folks consider it on the same level as an Optimist - but with fewer rules. The easier it is to build, and the fewer worries about extra weight, I firmly believe the more interest the class will attract. Of course, some will opt for a purchased Bantock boat, others may find interest in the boat Siri (RCSails) has built and can provide. Doesn’t really matter except to get local clubs to offer a chance to sail only a couple while class continues to grow. As class expands, I am positive there will be some designs that shake out both positive as well as negative. As you note, if not many in the area, it is hard to compare. South America reports some really ultralight boats, but they don’t seem (from what I recall) to set the RG world on fire. I think the class has grown and matured in the past 30 years because of free designs, and also designs for an easy build. This is what made the class appealing to me to begin, the ability to develope was a secondary plus.
Did you ask Eric about owners up your way? He took over as class secretary about a year ago, so I have lost track of where new builders are coming from - but like many classes there are talkers and builders. Only the builders can influence the class.
Cheers - and pst a few construction photos as there are some waiting to give it a try.
Dick
HI Niel,
the RG65 are for the time being, only a base for my Rigging tests.
The first was the Delta-Rig,
the second, described above, is the CD-Rig and
the third will be the DC-Rig.
For matter of comparaison I have made two hulls with different draft.
That’s all for now.
In term of performances I was informed that my previous design, the Blue Dragon was performing well in Argentina.
The actual “build log” are discussing construction details for those are interested upon and at the same time would be a source of discussion about the sail’s design that is the ‘engine’ of our boats.
Strage enough the sail’s design is still a very poor argument.
Cheers
Claudio
Hi Claudio,
I think that your rig designs are interesting. Working on the “engines” is not as sexy for a lot of guys as discussing the merits of different hulls. Having worked extensively with swing rig concepts, and having published a few designs of my own I know how much visualization is involved, and that is much more difficult than just drawing a set of hull lines. But, it takes a while and a whole lot of testing for the admiring public to adopt a new rig idea. Proof is in the pudding!
Hi Niel,
the reasons pushing me in that direction is because I think that the weighting factors are :
Hull = 15%
Sails = 35%
Tuning &Tumbs = 50%
Cheers
Cd
hi everyone,
looks like it’s turning into rough discussion…
so i’ll just leave some pictures of my open60 first print, waiting some 8 hours to total polymerization. One is showing the comparison between “Alinghi SUI100” and “Safran”, both at 1:20 scale.
I’ve also drawn the sail plan; reducing from 1:1 to 1:20 scale = 6300cm² ( looks good )
could someone explain me how to find the CV ?
cheers,
Paulin
Hi Cladio -
this post appeared on the U.S. RG website. I thought I would pass it on to you - perhaps ne (or both) of your RG boats could compete? Regards, Dick
Re: [RG65SailboatsUS] RG65 World Championship - 2010- information.
Hi RG’men !
Excuse my poor english !
This sunday there are Seven RGs at Codollet (south of France) !
Don’t forget 10 11 july : first Régate Internationale de Magny de RG65
Near Disney Ressort Paris (4km)
[i]http://nmmve.free.fr[/i]
Cheers
fr
PS Si Pascal peut en dire plus, c’est avec plaisir, son anglais est bien mailleur que le mien.