John949

I shall be interested in John B's take on this but mine is: In the video 71 gives mark room and then turns to sail directly to the correct side of the mark. It's hard to argue that her proper course is not to sail sirectly to the mark if she can. Anyone 'caught' in the closing gap has no rights and must keep clear, even if that means sailing the wrong side of the mark, but yes she can't luff above a direct course to the mark. Rule 14 applies to the interloper as well and also states that the RoW does not need to respond until it is clear that the other boat is failing to keep clear. Thus the onus is on the interloper to avoid the collision. The purpose of rule 14 is to prevent serious injury / damage not to give keep clear boats an excuse when they contact another boat. Usually both boats will be disqualified if rule 14 is relevant. Rule 16.1 Is a boat rounding a mark changing course or sailing her proper course? Over to you John B. BTW there is no proper course before the start signal so you can luff up head to wind if you want, but yes you must give room to keep clear. Note that this doesn't mean the windward boat doesn't have to try and keep clear. Leeward is only in the wrong if it is considered IMPOSSIBLE for windward to avoid contact.

Unfortunately I think this is more of an attitude problem than a rules problem. Until people accept that a boat clear ahead is entitled to round the mark first and stop trying to overtake by pushing in and hoping to get away with it, then incidents like this will continue to occur.

A thin character followed by a character with a rounded bottom followed by an R? I'd call that a clue. The original 10R rules meant that anything could be registered as a 10R if waterline length (metres) * sail area (square metres) * 8 <= 10. A Marblehead with a larger rig makes a brilliant light airs 10R. The rule is based upon a full size yacht rating formula from the 1850s. The earliest boats were free sailing and had some weird fin / rudder designs to make then sail in a striaght line. I grant you that the hull shape and the jib foot fitting are very A like. The 10R rules mean that that most designers would choose circular underwater cross sections and very fair transverse sections to minimise wetted area. Maybe someone found an old A hull and made a 10R rig for it?

One thing I found useful was to make a set of 'outside' templates. Once you start fairing the mould it's amazing how far out of true you can get, particulalry between stations. If you hold the larger template between stations you can judge the eveness of the gaps. For the last one I made a cradle of outer templates on the strongback to hold the hull true while a put in the keel box etc. The bare shell is very flexible and easy to twist and distort if it is not properly supported

I like the fact that it only has shrouds on one side - a proa perhaps? Your plan shows the winch drum above the deck. I haven't seen a boat like this in years and would highly recommend having the drum below the deck as it is so much easier to keep the water out like this. You will need to choose between a continuous winch line and a single ended winch line and whether to have the winch line (and the tensioner) above or below the deck. The latter looks better but is so much harder to repair at the lakeside. On my 10Rs I use 2 winches with single ended winch lines exiting right at the stern and these pull the sheets directly. This saves the friction (and expense) of turning blocks. I tension the lines with fishing pole elastic that runs in a loop to the bow and joins the two winch lines. There are many other ways of doing it and I seem to be in a minority of one in using two winches.

https://www.sailsetc2.com/downloads/RP14CX%20swing%20rig%20kit%20plans.pdf The above doesn't fully explain it but might give you some clues. Your call but I'm not a fan of the gizmo. Unless you understand what it does and definitely want those properties then it might be simpler to remove it and stick to conventional sheeting, at least until you get some experience with the boat.

The bare hull without any fittings is around 600g. The complete hull including the rudder, servos and batteries is 984g. As a comparison my complete Starkers M weighs 800g so I could still do better. Not having a minimum weight for either the 10R or the M is a very bad idea. It encourages very delicate hulls which can be damaged in a minor collision. There aren't many old 10R / M carbon boats about (Bentleys excepted) because they tend to fall apart and this reduced the number of cheap 'beginners' boats around. The IOM rules are much more sensible in this respect as having a minimum hull weight means most boats are built strong enough to last (I am currently sailing IOM No 961). However why the IOM rules don't allow carbon hulls and masts is beyond me. The latter are cheaper and stiffer.

Well it will certainly be stiff. As a guide my hull shells come out of the mould at about 250-300gm. I aimed to make the complete hull under 500gm but I haven't managd it yet. They always seem to need more filling / painting than I want, even when made in a female mold.

What construction method are you planning? I have designed and built several carbon 10Rs and could probably help you avoid a few pitfalls if you're interested.

As suggested, first try the winch in another channel. If it still does it, then dirt / corrosion / damage in the winch feedback pot is most likely. If you can dismantle the winch and spray contact cleaner onto the track, then this might cure it. The problem is that having gone bad once, it is likely to do it again. If it's an RMG then replacing the pot is fairly easy (though expensive for the older 10 turn types). For other types, manufacturer's spares are hard to come by and finding a generic part that fits properly is also tricky. Depends how seriously you sail, but a new winch and keep this one as a spare might be the best option for a non-RMG.

Note that the term 'full & by' was dropped from the RRS many many years ago - replaced by 'close hauled course' Oops, showing my age. Still I do know that the "overtaking boat keeps clear" rule was dropped equally long ago (unlike a lot of people it seems). It is one of the (many) difficulties of Radio Sailing that judging "proper course" when sailing perpendicular to the observer is not easy. My understanding is that if you get overlapped to leeward you are required to keep clear and protest afterwards (if you believe the leeward boat is sailing above her proper course) - not ignore the leeward boat and watch the boats raft up.

In a similar vein, a yacht tacking from port to starboard does not gain starboard tack rights until her sails are full on the new tack. In my opinion, if the port tack vessel has to start an evasive manoeuvre before the starboard tack yacht's sails are full, then the tacking yacht has broken Ruel 13. Unfortunately I seem to be in a minority on this point as yachts to leeward and slightly ahead on port think they can tack with impunity and yell starboard as they come head to wind,

I may be a bit out of date as I haven't used a gelcoat in a while but my understanding is: The gelcoat you linked to is a polyester gelcoat whereas the lay-up info claims it is an epoxy gelcoat. I'm not entirely certain but I though there is no such thing as an epoxy gelcoat and you have to use a special type of polyester that is compatible with an epoxy lay up. See https://www.easycomposites.co.uk/epoxy-bonding-polyester-gelcoat-clear Standard Polyester gelcoats don't set hard when exposed to air i.e. they remain tacky. This makes 'filling scratches' difficult. For more serious damage you used to have to make a mould to fit on the outside, then put the gelcoat on first from the inside and then use mat over it. Perhaps someone who has tried more recently could provide some feedback but I would be wary of making it worse. In my day we just used to live with gelcoat cracks. The boats I have made recently don't have a gelcoat (carbon / epoxy).

I do actually know what a sans serif font is. What I don't know is which (if any version) of the figure 4 counts as being sans serif or indeed if sans serif has any meaning when applied to numbers. If you are being really pedantic then you could perhaps argue that the figure 1 should be just a vertical line without the tick at the top but since Helvetica has it then go figure. Ironically serifs are used to improve legibility of small letters (or big ones at long range?) which is why optician's eye charts use san serif fonts i.e. it is harder to 'guess' the letter. Hopefully I have made my point about the rules perhaps not being as clear as they could be but, since the font doesn't affect boat speed, it's probably time I let it rest.

The rules say: (IRSA Supplementary Class Rules - https://radiosailing.org/download/irsa-supplementary-class-rules-2020-4/ C.11 IDENTIFICATION ON SAILS C.11.1 A boat shall display: (a) her class insignia and (b) a sail number on all sails and (c) national letters on her mainsail as required by C.12.1. C.11.2 National letters and sail numbers shall be in capital letters and Arabic numerals, clearly legible and of the same colour. The colour shall contrast with the colour of the body of sail. Commercially available typefaces giving the same or better legibility than Helvetica are acceptable. Digital fonts are not acceptable. I know it's easy to criticise and I'm more aware than most how hard it is to write good rules but the above are a beautiful example of how not to do it. Firstly Google Arabic numerals and see what you get! Secondly, "typefaces giving the same or better legibility than Helvetica ..." is entirely subjective; and thirdly what on earth is a " digital font" in this context? I recently acquired a vinyl cutter and was trying to find out which variation of the figure four I should use. The Racing Rules of Sailing (G1.2 a (4)) say " a sans serif typeface" so I'm none the wiser.

Just noticed that F.5.2 (a) says that a headsail boom swivel is mandatory. Does that mean I can't just use a cord (like a DF does) and I have to have a physical swivel? Anyone know what constitutes a swivel or what the point of this rule is?

In theory you can calculate the best position for the hounds and the spreaders if you know the loading on the mast (assuming you goal is to minimise the mast bend). In practice the loading varies with so many things (incidence, camber, mainsail twist, wind speed, etc.) that I'm not sure it's worth trying. Perhaps it is easier to consider what happens at the extremes and then decide if your rig is tending towards one of them too much. If the hounds are too low then the top of the mast will bend off too much, the leech will open and you will likely get a crease running down from the hounds towards the clew. If the hounds are too high the mast may bend excessively between the hounds and the foot. This may well induce a crease form the hounds to the clew. It will definitely stiffen up the top of the mast and lessen the tendency for the leech to open in a gust. Is this a good thing at the top end of the rig's range? I think the spreaders should be at a point where the bending moment above them is equal to the bending moment below them i.e. at the height of the aerodynamic centre. But of course the aerodynamic centre moves around with the same variables (particularly mainsail twist). Personally I would go with practical experience and perceived wisdom unless I was trying to cure a particular problem with the rig.

Many years ago I took part in something called the Classmaster Event. Three entrants from almost every singlehanded class sailed their own boats and then each of the other classes in a series of handicap races. This certainly removed the bias from sailing your own class (I'd barely seen an International Canoe before I had to sail one!). Something similar for RC Classes would require the equivalent of PY numbers for each class but any class handicap advantage evens out because you have to sail all the classes. More recently I took part in the DeQuincy Cup organised by the London Model Yacht Club. This was team racing in 10Rs. I believe they used 95s the following year.

Assuming you have the mast and the jib as far back as you can then try increasing the mast rake. It may be that the rigs are poorly designed - the jibs are too big for the size of the main and therefore there is not a lot you can do within the rules.

Not familiar with the FS-8 but I do know that FlySky have recently introduced a new protocol (ANT) which is not compatible with old Rxs (AFHDS) . Is it possible that the upgrade is using ANT by default? Maybe you can choose the protocol somewhere in the setup?

Are you making the sails yourself or buying them? Marblehead rigs sort of design themselves because of the way the rules work. First thing to decide is the balance between main and jib areas. For a conventional rig this is usually about 60 / 40 (70 /30 for a swing rig). A rig should have the longest luff allowable (depends on you kicker arrangement - read the rules) and as said you take about 200mm of the luff for the B and 400 for the C. Obviously you want to maximise the 'free' areas of the roach and foot. Once you have the luff then you can calculate the foot to give the required area and the maximum 'free' cross widths then come from the rules. If you sail predominately inland you might want to increase the 3/4 width of the main by about 15mm or so and 1/2 by about 7 and hence reduce the foot to compensate. Jib is similar but you can play around with the luff length to some extent. It's tempting to go for a long luff (higher aspect ratio) but the rules force the foot to be too short for the 1/4 width (particularly for a swing ring) and you end up with too much roach to control properly. If you look on Frank Russell's site he gives dimensions for his Gothic design and Graham Bantock (Sailsetc) has quite a lot of information on his designs. Best idea is to create a spreadsheet so you can play around with the dimensions and then draw out likely candidates (I use a roll of lining paper - cheap)

The tapping size for M4 is 3.3mm so there will be some thread left after you drill it for M4 - not ideal. You would need to use a drill press, or preferably a lathe, to stop the tap wandering and producing a 'drunken' thread. BTW I can find M3.5 socket headed stainless steel screws on eBay.

Many people (me included) use the 'exponential' function on the rudder. This makes the rudder less sensitive (i.e. more stick movement for a given rudder angle) around the centre of travel and more sensitive at the extremes of travel. Most simple radios have a function called exponential and you can set a percentage - the higher the percentage the less sensitive it is in the centre. More complex radios have a function called 'curves' which allows you define any relationship between stick and rudder you want. Pretty sure the I8 will allow you to use a three position switch to set how much exponential is in use. I have up - no exponential, mid - mild exponential, down - high exponential. I very rarely change it from the middle position. Not convinced that different throws or different sensitivities for different sailing angles is the right way to go but whatever works for you. Other people don't bother with exponentials or curves and just practice making small movements. Modern radios can do all sorts of clever things and such functions can be useful but if you are just starting out then probably best to keep it simple.

Try this: It's a bit frantic and you may not follow all of it (unless you are familiar with Bernoulli's equation and know what the Navier-Stokes equations are about) but the thing to take away is that the explanation of how a wing produces lift is complex and can only properly be explained using some fairly complex maths and therefore all the simple "molecules speeding up" or ^bouncing off the surface" explanations are nonsense.

In the interest of balance I'd like to propose an alternate theory regarding sail twist. I am not saying I'm right and you're wrong just proposing another possible explanation of why sail twist might work. The wind does indeed increase in average speed with height and it also rotates in direction with height due to the rotation of the earth. but these effects are very small over the height of a model yacht sail. More importantly the wind at ground level is far from stable in either speed or direction due to the turbulence caused by trees etc inland and waves at sea. I find it hard to believe that the flow is stable enough (lamina if you will) for you to be able to tune the sail twist to the variation in velocity. What is certain is that the more you sheet in the more force you produce (until the sail stalls), but the more you sheet in the more this force is directed sideways rather then forwards. Sail twist can be used to 'unload' the upper section of the sail thereby reducing the heeling moment and hence the hull drag In other words the lower section of the sail is producing more lift and but also more heeling moment. The upper section is producing less lift, but since it is directed further towards the intended direction of travel, the loss in 'drive' is more than compensated by the reduction the heeling moment. I actually sail my boats with very little sail twist, although you can have a reasonable amount of twist upwind it just looks wrong to have a lot of twist downwind when the sail is stalled. With a stalled sail I think you want to present the maximum projected area to the wind so this means having very little twist. On the subject of how a wing produces lift, it would be a disservice to all those people who tried to teach me aerodynamics if I didn't point out that the "air has to travel further over the top of the wing therefore it must travel faster" argument is a common mis-conception or perhaps more correctly: only part of the story. This argument struggles to explain how an aircraft with a symmetrical wing can fly at all or how an aircraft with a conventionally cambered aerofoil can fly upside down. It also struggles with a yacht sail (technically a cambered flat plate) as there is no difference in the distance the air must travel between the windward and leeward sides. This isn't the place to explain aerodynamics (and I'm not the best person to do it anyway) but perhaps if you look at the diagram you drew and replace the cambered section with a symmetrical section, think of the fluid as water rather than air and call it a rudder not a wing: then maybe it's easier to see that the change in direction of the fluid flow must cause a force on the rudder?