On her launch day she did get wet but the wind was just a little too strong to release her,at this stage.
Photo thanks to John O'callaghan

To help understand my reluctance to release her in what appears to be light winds,firstly note the Pacer in the background sailing with a decent amount of power.
Nicorette has a huge sail area and a light keel and is totally dependant on the canting of the keel,exactly like the real boat,that's the design.
First time out will be with the keel in nuetral position under semi-manual control so that I can just stooge around checking all her function and testing the effect of the keel on the boat as I cant it from side to side,windward and leeward.
Then when I'm confident that the mechanics and the electronics are functioning OK under these light loads I can switch her to full auto canting keel mode and start working her up.
To launch her in winds above about 4 knots, in which she is totally dependant on the reliable operation of her keel,where any failure could severely damage the boat due to lack of control, would be heartbreaking.

The old green girl-SH start at left and my 1.7 m model right

2004 Nicorette - 2 metre RC Model
Introduction
The Hull
Deck Construction
Internal Structures
Keel Mechanism
Custom servos and winches
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Introduction

If you've read my ramblings in the 'concept' section,I have a set of drawing for Ludde Ingvall's new 90 ft (27 m) Nicorette Maxi yacht,and also had full access to the building process and information at Woolwich Docks,where she was being built by The Bigboatracing team. I wish also to add here,that unlike most other Maxi yacht owners/skippers/designers/etc, Ludde is an open book with no secrets. He allowed full public access to the work site for which he had a spectator platform available plus live internet video feed of the building activities. My model has been a 2 year project,for which I have developed some new ways of doing just about everything it takes to build a model yacht. The model has 15 moulded components,the plugs for each one crafted from scratch to produce the moulds from which then all components are moulded in carbon fibre. She's very close to 1/14 scale at 1960 mm LOA,with a target all up weight of about 9 kg, approx 3.5 kg in the keel bulb. My aim is to make her as close as I can to exact scale with most of her deck fittings, some functional deck winches,and fully detailed sails. As there is no commercially available teadropped/tracked mast in either carbon or aluminium, I will need to design and build my own. The hull is of carbon fibre/nomex honeycombe sandwich of 4mm total thichness,all internal supports and many other components are fabricated from carbon fibre/herex foam sandwich also 4mm total thickness. While this section is intended to detail and show via photos of the construction process,I will be keeping it fairly brief and without getting too technical or too much blow by blow descriptions. A 3DsMax computer generated 3D model of the proposed 2004 Nicorette RC model. (click arrow bottom left corner to play 15 sec video clip) If you'd like to talk with me about this project you can phone me:- Stan Allen (02) 9457 9211 or send an email

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The Hull

Building the Plug Unlike conventional moulding of model yacht hulls,this hull will be layed up over a 'male' mould,due mainly to the carbon/nomex sandwich construction,and exactly as the real boat was built. After they released the real boat from the timber plug mould,they got to the plug with chain saws and destroyed it. To lay up and vacuum bag the sandwich and epoxy resin inside a 'female' mould is an almost impossible task,a disadvantage is that the outer surface will have to be 'faired' as it will not have a shiny smooth finish as would be achieved from a 'female' mould. The advantage is that the 'stiffish' 3mm nomex is easier to bag over the convex surface of a 'male' mould than it is to bag against the cancave surface of a 'female' mould,thereby ensuring that the carbon cloth on the inner and outer skins is far easier to control and not be distorted and 'torn' which would be impossible to avoid with a 'female' mould. Another aspect is that the 'moulding' surface of the plug doesn't have to be as perfectly finished as it would need to be for making a 'female' mould from it,just needs to be the right shape with a reasonably good enough surface finish to 'release' from. The Plug. All the usual suspects,paper prints of all the formers glued to timber,in this case 3mm craftwood,cut to shape and attached to a sturdy building board with 50mm spacing, no stringers used. A few requirements built in here:- * building board screwed to the bench so that the buildup of filler wont 'banana' the whole thing (removable). * the plug screwed to the BB (and removable) via strongly supported mounting blocks within the plug. * a large 'hold' in the middle of the plug,at a later stage it will be removed from the BB,weighted down and floated to it's approx LWL to check the accuracy of the CB (center of buoyancy) position. * the hull sides need to be at least 30mm higher to allow for an overun of the sandwich layeup, the gunwalls can then be trimmed to final shape. What to fill the 50mm spaces between the formers with? Plank it,foam,gotta be a quicker easier way? There is,cover the skeleton with a reasonably tight open weave cloth that is impervious to polyester resin then skin with a layer or 2 of 3/4 oz chopped matt to seal the surface and provide a strong foundation for subsequent layers of micro balloons that will then sand to the desired shape. For the cloth I used Sailon shade cloth that I had,I'm sure there is better material available,the Sailon is a bit stiff,but it worked fine. Many applications of micro balloon batches and much sanding with constant profile checks,a coat of grey auto primer to seal the surface and it was into the test tank to check the CB position - right where it should be. From there it was just bring it up to shape and finish,ready to build a boat. check the pics below (click image to view full size) front view-formers on BB rear view-formers on BB draped in Sailon shade cloth 2 layers of 3/4 matt applied micro balloon build up begins and more micro balloons progressively closer to the shape ready to make a yacht hull Building the Hull In keeping with developing new techniques a certain degree of R&D is required and mistakes are inevitable through the process. My first was figuring out and implementing how I was going to achieve clean gunwall edges. I made 'U' shaped strips to both hold the nomex in place and provide a solid gunwall edging,the green strips seen along the hull in the last photo above are for setting these strips correctly. While everything I'd planned worked extremely well,the end result was a lot of extra fairing material on the outer skin and subsequently a lot of extra weight. I proceeded with the hull fairing through to a finished painted hull,then weight calculations ruled it out as viable. The hull with carbon/herex internal gunwall reinforcing strips was around 3 kg which would have resulted in a model weighing at least 12 kg and sitting down way beyond her LWL,my target weight was around 9 kg. Another aspect was my inner skin layup,I'd made this with multiple transverse overlaying panels causing a 'double' cloth thickness at these areas that was transfered through the nomex to the outer skin,which then required fairing. To elliminate the 2 problem aspects of my layup I decided to scrap the 'U' strips and make both inner and outer skins from single pieces of cloth. The raw nomex gunwall edges will be easily sealed with fairing cream once trimmed and there shouldn't be any 'bumps' transfered through the carbon/nomex,it should exactly duplicate the surface of the plug mould. Then I should be able to use auto primer instead of fairing cream to fill the surface texture,a much easier process and saving of bags of weight. The actual layup process is easy enough,apply the inner cloth 'dry' then use 3" wide paint rollers to carefully distort it and 'mould' it to the shape of the plug,then use the same rollers to work the epoxy resin into it. This is a beautifull method as no 'tearing' is caused to the cloth,every carbon strand is perfectly aligned,and using a roller,total control is achieved over resin quantity 'wetness',just like painting a wall. As you roll over the surface,dry spots are easily found when the cloth lifts or 'bubbles' behind the roller,and once the cloth is wetted out,it's amazing how much pressure can be applied with the roller. Lay down all the layers for vac bagging,turn on the vac pump at the required moment and let it cure off. Nomex layer-paint a light coat of resin to the cured inner skin (after sanding) to glue the nomex in place,then re-use the actual vac bag to hold it down and cure the 'glue'. Outer skin-applied exactly the same way as the inner skin with a little more attention to how much resin is pushed through into the air cavities of the nomex,though any extra will be sucked out anyway by the vac 'bleeder' layer. This bleeding process causes another problem common to light weight single layer FG components,pinholes,literally thousands of them. The 'bleeder' is sucking air out of the nomex cavities through the outer skin and I'm not sure if this can be avoided,except perhaps by adding an extra layer of cloth to the outer skin after the first one has cured off. Should work fine if weight is not an issue,but select carefully the weather conditions when this is done. The inner skin should be perfectly sealed and solid,so variations in ambient temp will expand/contract the trapped air in the nomex,possibly resulting in an outer skin surface that will always show a degree of 'texture'. My favourite filling method-a slurry of Polyfiller wiped over the entire surface,used many times with model aircaft moulded components. Very light and extremely easy to sand off. Success,the bare hull with the carbon/herex gunwall reinforcings fitted was now down to 1.2 kg. check the pics below (click image to view full size) 2 nd beside 1 st the bare lightweight hull front bulkhead & gunwall strips down the inside

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Deck Construction

Design Requirements For my original Nicorette (the old green girl),I'd built terrible deck/gunwall seals. As with her,the whole deck would be in sections and all of them removable for clear access to the hull's interior. Had to be as close to scale as I could make. Plug Construction I'm not going into blow by blow of how these were made,the photos below will serve that purpose sufficiently. The carbon/herex gunwall strips serve as a ledge for the side flanges of the deck panels to locate on,they're an exact fit against the inner hull skin to make a better water seal. The balsa plug is built with double cross beams in those places where it will be later seperated out into it's various sections and overlapping joints added on. A tip I will pass on though,that I used to exactly fit my deck edge flanges to the inner skin. To exactly shape a surface/object to another using epoxy resin alone or with fairing cream mixed in. Liberally coat the parent surface with mould release wax,rub it on well and with full coverage and leave it 'wet',don't buff it,just let it dry off. If the adjoining surfaces are to be later painted,first apply sufficient layers of masking tape to allow for the paint thickness,then apply the 'wet' wax to the masking tape. The 2 surfaces will release so easily that it will amaze you,it did for me. check the pics below (click image to view full size) about 1/2 done frame completed frame detailed cockpit cockpit out-deck sanded wanted to view in test tank easily removed-wet wax joining lips added to sections preperations for building moulds

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Internal Structures

Design Requirements Well,we all know what happened during the 2004 SH,Skandia losing her keel and Konica Minolta cracking in half,well,she crinkled anyway. Big waves,long hulls,very poor interior strength,IMHO. Nicorette was and I believe still is,a maxi yacht with a good deal of interior hull strength,but even she could be better. I think her longitudinal vertical supports under the cockpit should extend right foreward as far as possible to the bow,it'd take a lot to break her then. There are photos below showing her interior - thanks to The Bigboatracing Team. While I don't think for a minute that my model is going to be subjected to the same conditions or require any where near the internal strength that the prototype requires, I have other reasons for building a complex internal structure. All of the models operating systems will be below deck,closed loop winch systems,several other winch systems,nicad battery packs,retracting cunard,wires/plugs and switches,and of course the canting keel mechanism. I need an internal structure to house and support it all,minimal,light,yet sufficiently strong enough for the task.And I want it to look somewhat like the guts of the real boat. Building it Like a lot of things,designing is the difficult part,building is easy. Basically,lay a 1/4" wide strip of 1/16" th balsa along the desired path inside the hull,hold down with masking tape where necessary and 'crack' where required to shape to tight radii. Build the surrounding framework (top,sides,etc) and fill in the middle with strips,glue with cyno but be carefull not to glue to the hull,it has to be easily removed without breaking. Check photos below. Copy to carbon/herex panels and proceed from there. A sidenote - these and the decks were all built to the first 'heavier hull',but because both were built on the same 'male' mould,the inner shapes are identical. (click image to view full size) inside the prototype canting keel support frames supports under the cockpit the balsa templates cuttout in carbon/herex stern view-trial fitted top view-trial fitted with most parts fitted

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Keel Mechanism

Design Requirements Where to start with this one? Unless you're a little familiar with the canting keel mechanism's on the real boats,it's going to be difficult to explain the model's.As I slowly put all this info together it will all be eventually featured in the 'How To' section. A list of requirements:- 1. has to be strong enough to withstand occasional collisions with the 'bottom'. 2. has to support the weight of the keel and sailing pressures when canted over to max angle,approx 40 deg. 3. move freely about it's pivot axis. 4. has to be watertight,have an effective 'wetbox'. 5. the canting mechanism has to be sufficiently powerfull and move at a reasonable speed. 6. must have 'failsafes'. 7. must operate automatically as I will not be able to tell very much from shore. 8. must be fully serviceable. When you work out some of the forces at play with this,they're horrendous,and it all has to be as strong and light weight as possible. To start with there are the pure physical properties of the keel itself. The ratio of keel bulb and the top of the 'tang',that it will be swung by,about the pivot axis is 3.3:1. The bulb weighs 3.5 kg (whole keel 3.8 kg) so that equates to 11.5 kg at the tang, the total wght lifts that to 12.54 kg.That force is being applied to a tang height of 100mm about the axis. Add to that any forces applied whilst under sail and particularly in rough water,and the forces at work are unimaginable and beyond my ability to calculate. When the forces at play in a real Maxi yacht are concidered,where the loads impacted into the mechanism are in the 100's of tons in the extreme,it's easy to understand why they have some dramatic failures. To imagine a large maxi with the keel fully canted and 'launching' off the back of a huge wave,where the keel would break the surface,then 'slap' back down,I wouldn't like to be below deck at that moment. Description in brief In keeping this brief I'll let the pictures do their job and add that the aluminium main frame with SS ballraced pivot shaft is fitted very snuggly and bolted into a fairly solid carbon/herex box between 2 bulkheads that should keep it all in one piece. That's about all the detail I am willing to give at this point in time. Once I have tested all her functions and have confidence that the canting keel mechanism, controls,and functionality are working as concepted and designed,I will add full details to this section. (click image to view full size) canting keel mech mainframe looking aft auto control device set up for testing

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Custom servos and winches

Design Requirements As with everything else in this model,light weight is critical for all components. With RMG winches for jib and mainsail,the whole canting keel mechanism,and carrying 2 x 2700 MAH battery packs,the challenge was ahead of me to find some very light servos and winches with sufficient power to control a few trim functions that would give me the same control over her sails as the real boats have,by RC. Namely:- 1. mainsail leach tension (vang) 2. mainsail foot tension 3. headsail leach tension 4. headsail slot adjustment 5. extend/retracting cunard Solving the problem At my local hobby shop I found sub-miniature servos for the electric powered park flyer aircraft that seemed to have sufficient torque for the job. Having carried out modifications and various repairs to RMG sailwinches in the past,here was a source of quality gears of various types. (check pic-'miniature winch components') First task,modify servo to rotate output shaft continuously. Disconnect feedback pot,replace and extend wires outside of case for attachment to a remote pot. Make an aluminium shaft to carry the worm drive gear and a brass tube shaft for the large output gear,the latter to have a hex brass tube insert to transmit the drive and allow the insertion/removal of drums,winches,etc. Build a frame out of carbon/herex to hold it all together. Bushes,lock pins,screws,cyno,a feedback pot,and there's a sub-miniature winch weighing less than 20 grms. By calibrating the remote feedback pot with a resistor in parrallel,the number of output shaft rotations can be adjusted,most of mine have a single turn.The exception being the one with the large red pot. This one is using an RMG 10 turn pot from the latest HD winch and calibrated with a resistor in parrallel to give about 20 turns of the output shaft.This is fitted at the base of the fixed mast section, driving a lead screw that adjusts the mainboom gooseneck up and down.With the vang fixed,this then raises and lowers the outer end of the boom providing the mainsail leach adjustment. The mainsail foot tension mechanism is powered by the same servo type with a leadscrew output shaft and remote mounted feedback pot. (check pic-'miniature custom winches') Assy at left shows an SM winch with a deck winch attached,there are 3 off these functional on the model,3 of the 4 small ones aft of the cabin. 1 each for port/starboard jib leach adjustment,operating together,the other is for the jib luff tension which is operated by manual switches housed in the display box underneath the boom against the back of the mast.The mainsail luff is controlled from the same box but has a different system. As the model is rigged for mainsail reefing,this system required a below deck 'closed loop' with about 960 mm of travel,feeding up on deck through the 4 th of the small ones aft of the cabin. (click image to view full size) jib slot mechanism assy mainsail foot tension mech miniature custom winches miniature winch components

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