Jump to content

Richard98

MYA Member
  • Posts

    76
  • Joined

  • Last visited

  • Days Won

    1

Richard98 last won the day on April 25 2019

Richard98 had the most liked content!

Reputation

1 Neutral

About Richard98

Personal Information

  • First Name
    Richard
  • Last Name
    Moroney

Recent Profile Visitors

1,266 profile views
  1. Thank you Tiggy_cat, had a look at those two. Both pretty heavy displacement hulls I'm afraid. Pieces of Eight looks about the sort of hull ; Thank you Shaun. Long and thin and easily adjusted from lines for a 4Kg all up weight. Will try to see if any lines are available.
  2. Looking to build a 10R since there seem to be no second hand hulls around. I remember seeing a chined design on here some time ago, but can no longer find it. I know that this hull form is not necessarily the best, but I can cobble one together in a few days; as previously done for a foiling Mini40 not so long ago (now sold on) Also cheap as chips and light enough to come close to CF in that hull form. Can anyone point me in the direction of the lines for that chined 10R ?? I do remember that it was a well known designer. Richard
  3. Agree with you there John. I did put a few M's together with a specific request to make them dual rated. I tried a 10R rig on the M and was impressed with the "upgrade" Obviously not going to compete with the 10R hull in a wind, but boy; did it go. I also briefly tried a 10R rig on my Starkers and, once again, it was like adding a supercharger. GB beat the 10R's with the Paradox in light winds, so could almost come down to where you sail. Richard
  4. Thanks John and Eric. I am looking at CR2020, which I assume must be more up to date than the 2018 issue. So the max fin length , with ballast attached, is 660mm then the hull draft is added giving a draught of >700mm. That sort of equates to the 10R for the purposes of dual rating and is what I will aim for. When I built Paradoxes the draught was a mere 600mm. Thinking ahead to next project. Richard
  5. When I had my Marblehead I was aware that, despite having a very long fin, newer boats were even longer. Therefore I could not expect to compete with them, except in light winds. My fin was already too deep for our main sailing venue and these considerations led to me selling the boat. What is the maximum draft allowed ? Measurement rule C5.2 only refers to a gauge with no indication as to what size it should be. Just curious really.
  6. Back on the water and I have realised that I love these big boats. So many different considerations compared to the full waterline, slimmer boats. I now have a B rig and I attach pictures for comparison. Some will recognise the origin of this B rig. That gives me 1.0sq M and 0.6 sq M respectively on the same luff length of 1720mm. I realise that the boat is way too stiff and have reduced the ballast to 5Kg, which brings the overall weight to <8kg. The A rig brings the boat up to hull speed very quickly and it needs to heel to bring in the free additional waterline provided by the overhangs. Hence the ballast reduction Changing down to the B rig takes 2 minutes and is soooooo easy with the shroudless rig. Therefore the boat remains in its speed groove better. I anticipate an IOM B rig as the C rig for this boat and this combination should see it sailing consistently within its "sweet spot" Also going to reduce the trim tab area a bit more, although I have still not been able to evaluate it against another boat yet. The boat draws considerable attention due to its impressive size and is proving a joy to sail Richard
  7. Assume you back up to the water and launch off that ramp with the boat on a trolley. Neat. Richard
  8. I can confirm that what Brad recommends does work. I used his settings for standing rigging and bent the mast accordingly. Then a little trial and error with the ram and shrouds produced the desired result. Boat "Alternative" Brad Gibson, Sails BG. Can only reiterate that pre bend is essential and will not necessarily be the same values for different sailmakers sails and rig set up. Richard
  9. Hi again John, Just re visiting your US 1M having noticed that you have changed to shroudless and therefore forestalled my question. Worth pointing out to potential new class members; that the sail area you quoted is just the triangle area and that a substantial free roach area is up for grabs. My target for my dual rated project boat seems to be 525600 sq mm which is approaching the IOM sail area. (rough calc only) This small difference may be what made the initial sailing in the company of a US 1M so close when balanced with the reduced displacement and wetted area. I really like your pocket main and would be interested to hear how you configured the pocket. I have resorted to multiple tabs on any test sails I have made; sort of works but not ideal. Also are you using a built up mast to obtain a nice luff curve and still maintain a consistent wing effect at the training edge ? Fully understand if any of this forms a "trade secret" but I am always experimenting with these fundamentals, often with surprising effects. Richard
  10. Legal rig ??? Just been re visiting the 6M rules after looking at some older posts on the subject of rigs. I know that the rule allows only one mast and my carbon un stayed mast is legal. However it appears that a pocket luff mainsail is not prohibited. 5.3.2 states that "double luff mainsails are prohibited" Why are no 6M's being rigged with un stayed masts and pocket luff mains ? Richard
  11. Hi Robin, my two, old, well used Star yachts just straddle the models you have. SY4 and Endeavour 1V. Not sailed either for a very long time. I have re rigged though and stuck with the white string and dowel spars. Looks nicer and works with the original bowsies. Endeavour's sails are a little "mothy" now but still look ok. There are loads of pics of all the boats on the internet. Widget is still a handy IOM and I remember the Cockatoo, which was popular in New Zealand; most of the fleet at Glenfield I remember. Richard
  12. Hi Guzzilazz, there is no need for the complexity of metallurgical analysis here; it is simply a question of mechanics. The pre bend requires backstay to just to bring it straightish and this is the starting point. The forestay tension to get to this point alone is the bonus that pre bend gives and the reason it is so important. More pre bend = more forestay tension for a given luff shape plotted down to less tension for less. We are stuck with a very flexible alloy tube and it is very important to match the pre bend to the sailmakers luff profile and this is not easy. Get it in the wrong place and you will have problems. That is a good reason to ask the sailmaker, or get them to do it, what the mast bend position and amount should be. Like so many settings, there are no empiric values and settings provided by experienced sailors will not necessarily suit all; but are invaluable as starting points. Personally I prefer side shrouds , but have yet to win the World Championship of course. Experimentation is great fun and the best way to understand the value of any adjustments. Richard
  13. These things are seriously addictive and you could do worse than contact Mike, above, for loads of info. Also Dave Potter at Potter Solutions. The Model Multihull web site has sadly lapsed, so it comes down to a handful of enthusiasts. Ian Holt "Perthmini40man" also has loads of development info. The holy grail of these boats is speed; particularly spectacular foiling. The three main considerations are weight, lightness and even less weight. I have built a couple now, the first being a modified "Ghost Train design" built from pre preg C/F and moulded in an autoclave. This design was one of the first to foil. As mentioned, really depends on what you are after. Let us know how you get on. Richard
  14. Quite right to look at updating rig; as the engine but I have found that the quality sails made by current suppliers rarely "stretch" and the loosening leach is quite likely to be a relaxation of the mast pre bend which is being compensated by extra backstay to maintain the jib luff. I have conducted strain gauge tests on the bendy aluminium masts that we are stuck with and they will relax fairly soon. There is a lot going on at the forestay intersection and it is constantly working. Also tried to find any differences between available masts. All are equally poor on bend analysis, some do seem to have a harder anodising though and this makes bending slightly more interesting. The relaxation at this point does not necessarily manifest as a dimensional change; rather an increase in bendiness. Here I can touch on the effect of rolling a pre bend. Get it right first time with absolute minimum passes or it will degrade the stiffness; actually measurable on the strain gauge. The harder coating does seem to require more working and I found it quite easy to warm up the test pieces with the two roller devices that I have tested. The amount of pre bend and where it is set is one reason for for experimenting. It must match the sail luff to be effective and not introduce creases. The need for pre bend is well covered elsewhere as is the reason for the fractional rig of the One Metre. Anyone who has tried to make sails and has found that the superb camber shapes from our current suppliers just cannot be re produced, will appreciate the correct positioning of the pre bend. We spend most of our setting up time at the water side fiddling with the mast settings to obtain a good sail shape; possibly the single most complicated tuning aspect of the class. Mast pre bend is as much of a "black art" as sail making and seriously overlooked. I note that sail makers offer this service and, just like trying to make your own, it must be worth paying for a mast to match the sails. The One Metre is an expensive boat to race competitively; some may say that this is due to peer pressure to use the absolute best equipment. Sadly fewer seem to take up the comments from the likes of Brad Gibson to "pimp" older designs. Now for the controversial bit: Carbon masts. I have rigged up an unstayed, 3 section carbon mast. A delight to assemble and cheap. No long pieces needed and perfectly adequate uni directional tube is no dearer than alloy tubing and no horrendous delivery cost. No pre bend is necessary, the only technical bit is positioning the telescoped joints in the tubes to achieve the correct bend when the backstay is set. My boat sails really well and the rig is sooo stiff. Maybe I will write more about this later. The main point of this missive was to add to the bending discussion. Richard
  15. Hello again Jorge, Had a look through my Paradox notes and remembered that Brad Gibson updated one fairly recently, with some success. One area was the fin and its location. The leading edge of the fin was moved aft to 627mm from the transom, measured along the hull. The fin rake is taken from a datum point 500mm down the L/E edge of the fin, from the hull. Then from the lower tip of the bow it is 855mm to this point. This would apply to Dave Creeds fin I believe. I do not have a Marblehead any more and I am sure that if you asked BG he would give further advice. Richard
×
×
  • Create New...