Daniel Holman

Members
  • Content count

    387
  • Joined

  • Last visited

Everything posted by Daniel Holman

  1. Daniel Holman

    Moth for sale

    I'm too superstitious for green. :-) Yes it seems like the production offerings are super refined alright. Yep if that boat were in the UK you could fetch double or triple the money as long as it was functional. Good on Dave C tho! He will have fantastic pride of ownership and a great ride.
  2. Daniel Holman

    Moth for sale

    I think (or I thought..) that $6k would be the absolute bottom for clean and functioning. Not any Mach 2s for that are there? Even dirty and broken. Does the exceptionally attractive / realistic price reflect the novelty of this craft, and that you maybe don't get the comfort blanket of off the shelf parts and knowledge base of users from M2 or Exocet etc
  3. Daniel Holman

    Moth for sale

    Good man! Protecting precious engineering capital!
  4. Daniel Holman

    Moth for sale

    Such a cool boat. Colour aside. Why are you selling? And what would you do differently given your time again that would make it the fastest moth in the world? Dan
  5. Daniel Holman

    Do Laser hulls deteriorate with use, or with time?

    I'm with JB on this. I owned around 10 lasers and as an engineer I can say that, unilke say the stayed boats he mentions i.e tasar, 29er, when purely sailing lasers are very understressed i.e. the low tech construction basically doesn't see much stress so doesn't degrade materially if being used as intended. So I would be happy (well, as happy as one can be to own the most heavily overpriced / marked up dinghy out there) to own a hull and as long as I looked after it and it didn't leak, I would expect it to be as good after say 500 sessions as it was after 50. The thing is its tough to decouple the hull from all the other things that go wrong / wear out on lasers. The spars are wildly inconsistent in wall thickness due to sloppy tolerances on the extrusion process, and further they are sh1t, bend and break if the rivets don't pull out first. The sails last a week of solid usage. The foils go porous / aerate. If your boat is a leaker it will absorb some water. Gudegeons loosen up. I could go on. Many aspects afflict all boats to one degree or another to be fair. Then you consider wear and tear - scratches on bottom, wear to mast step, damage from collisions / unintended usage / sitting in nettles for 20 years etc that will accrue on a boat that isn't looked after, and these things will cumulatively reduce performance slightly. Trade in deals meant it was convenient to chop mine in regularly in my tenure, as you get the fresh spars, sail and foils that you need, but if that didn't exist I'd be happy enough as a former national champ to keep the same hull as long as it was in good condition in the first place.
  6. Daniel Holman

    Which way the wind blows

    Gustavo Lima won the 2003 laser worlds from Robert Scheidt, one of a heap of laser glories he had particularly in the light. All that without using telltales, let alone a wind vane. I’d be a tail end punter without tell tales unless windy. Some bastards just have the knack. Dan
  7. That a moth mast tang? Gurit 345 has better shear strength than 340, is quite rubbery and challenging to mix well, but get it warm and its good, also ideal thickness for secondary bonding straight out of the tube. Its tougened with rubber particles or something like that so doesn't pick up shock like neat or filled conventional epoxies which are relatively brittle even if postcured. - Like Russel (who is a guru!) says, way to get all of the secondary bond shear strength is in surface prep, and rubbing the surfaces with the glue before adding the majority of the glue and clamping if app / necessary. Make sure if its a big part (unike this one) you have holes drilled in such that you can ensure that all air escapes and you get glue issuing from all edges. Get a tube of that 345 and a gun you will need it for mothing! I believe West do a similar product .
  8. Daniel Holman

    Kiwis lead JJ Giltinan

    Quite interesting all this and I reckon will act as a stimulus to the fleet. Certainly far more compelling to watch / understand than "Superfoilers!"
  9. Daniel Holman

    RS800 Video

    Ha I'm actually a southampton water person, but 14ing takes us to chi harbour a lot
  10. Daniel Holman

    RS800 Video

    Good stuff. We were out saturday, lighter but shiftier than what you had. Broke ice off the boat and had to get changed in the car park. Sunny tho. Brr
  11. Daniel Holman

    Gitana Maxi 17

    It’s not honeycomb it’s pinholed foam - ie foam intended for use under vacuum to prevent voids. The black spots are where the (black poss spa bond or some such) core bond adhesive gets into the pinholes which show that the whole vac bonding is working. The foam is probably the very dense stuff that has similar mech properties to oak. I dare say that structurally this is fine assuming there is a spar and like what somebody said, either damage or cavitation, which will eat bronze propellers. Think 40 plus kts alone won’t cause cavitation, but 40 plus kts plus enough negative pressure to “boil” the water, the subsequent collapse of the bubbles being what erodes the surface of the foil / prop. in propeller world, among other things you might look to reduce that pressure by increasing blade area, diameter, reducing pitch increasing revs or some Combination therof. Did any ac boats get this sort of damage? I suspect that the more offshore scenario of very variable loads with boat motion combined with going in and out of the waves in a transient manner may have precipitated this, and it probably would not be straightforward to just up the area. Making it monolithic would not help if it is cavitation erosion, you are still basically taking an watery angle grinder to the surface. Harder substance ie metal may reduce the rate of erosion but then you are into something heavier and bendier. Dan
  12. Daniel Holman

    Blue Balls

    Quality well done plenty time to get her “bay proof!”
  13. Daniel Holman

    VPP for dinghies and skiffs

    I could see that being the case. Only used that technique once, don't own a GPS, but it was interesting and esp if more than one boat in a race compares tracks it could be pretty interesting.
  14. Daniel Holman

    VPP for dinghies and skiffs

    Its a good piece of work, Sosoomi, although I reckon empirically in 10kts or more SOG at VMG angles would be ~ 4.5kts for RS200 - reckon if you fudge to fit to that the rest of the polar would be very valid. Computed polars are the output of VPPs and are used for 2 things - some yacht handicap rules, and for getting target boatspeeds. On a yacht with (properly calibrated!) instruments with SOG and TWS and TWA then you look at your polar especially upwind and also VMG running (when not in tactical situations where you are not on VMG angle) to work out whether you are sailing too high and slow, or too fast and free, i.e. to make sure that the optimum balance between induced drag (reduces with speed at same RM) and frictional drag (increases with speed) is met. Think many VPPs have optimum heel angles as well - important as with heel comes RM but you lose some efficiency and CLR moves. I'll be honest I don't see the value in the measured stuff. Even if you were clever and only sampled it during "steady state" sailing. You never know the TWS or TWA accurately enough on a dinghy for it to have value, and of course both change pretty dynamically, as do most things on a dinghy. Dan
  15. Daniel Holman

    I14 Capsize Compilation

    Good stuff, bet you slept well. plenty of that in the UK last few weekends.
  16. Daniel Holman

    Small home built beach cat?

    Home build small beach cat? Youll be wanting the woods designs pixie, seen on this YouTube round the corner from where I grew up: plans can Be bought from: http://www.sailingcatamarans.com/index.php/designs-2/46-beach-cats-and-dinghies/5-pixie-14
  17. Daniel Holman

    DC Designs

    Cheers guys how about the stringer frame boats i.e. as distinct from stressed ply - Machete etc
  18. Daniel Holman

    DC Designs

    Hi All, What scantling is used in the ply only IC's to get a boat down to 50kg sailing weight? I.e shell thickness, bulkhead thickness and spacing. Also Stringer scantling. Cheers!
  19. Daniel Holman

    Legal "Wingmast" for I/14

    Yep that is cuckoo #3. I think a number 4 is imminent. My intent was certainly to get a narrow waterline, but it still measures in as per r.o.f by a mm or two so that part of the intent was met. I think Archie in #2 has been having some race wins and great flashes in all conditions mixed with a load of teething issues. My season has been heavily interrupted by arrival of a second child. I only lined up properly last weekend vs other 14s and again had good spells but was rusty as hell, some rigging errors etc, some changes needed on rig. POW is in a few weeks so hopefully we can be all sorted and get a better idea on performance.
  20. Daniel Holman

    Legal "Wingmast" for I/14

    No sweat - always helps with the motivation / progress when trying to execute one's own silly design and build programs in the midst of a young family!
  21. Daniel Holman

    Legal "Wingmast" for I/14

    Think that you get a really big range of conditions in the U.K, plus there has never been that much culture in 14 of developing condition specific kit, possibly as a result of the expense, people choosing more to try and get the best through the range out of their rigs. You can get 4 seasons in one day here as well. some people run 2 jibs as allowed by rules but it only really opens you up to psyche out when you have to chose one. Seems on the whole that the U.K. Teams are superior internationally over the full range of conditions, with some Aus teams being very good in the breeze, some of the other international teams being strong in the light. Whether that is down to weight or condition specific setup or just skill/style it's hard to tell.
  22. Daniel Holman

    Performance gains without two boat testing

    Sog upwind maybe nearly wind speed up to 10kts in flat water up max to 12 kts on a very good day in wind. Bit footy. Less in waves. Bit more than wind speed downwind but topping out at high teens on vmg angles. biggest top speed instantaneous I've ever seen (by someone else) is 25kts. Think a new one sailed well will just have the better of a well sailed 49er in sub 12 kts, above that 49er rm takes over.
  23. Daniel Holman

    Performance gains without two boat testing

    If you are using a 505 to tune up something is very wrong with your 14 sailing. well sailed 14 tacks thru 50 deg ish give or take I don't think that's far off beach cat with dagger territory.
  24. Daniel Holman

    Performance gains without two boat testing

    Yeah time on water in a rigorous fashion focusing on going round corners, going through modes and gears whilst under pressure will make you better at sailing and yield decent results as long as your tactics are sound. I'll be honest for assessing developmental gains, apart from trusting your backside (ie seat of the pants feel) I think that apart from a very serious multi channel acquisition syTem and post processing capability, everything else is pretty dodgy at best. Its very easy to get another half knot letting some vang off, which won't be easy to associate with a couple degrees less height unless you have some very clever measuring stuff. Thinking laterally do you know anyone local with a 49er to line up with? Or a fastsh beach cat? A 14 should do a hobie 16 upwind but an f18 would probs do the 14. Maybe something in between.
  25. Daniel Holman

    Legal "Wingmast" for I/14

    Ben Gs effort is really first class I chanced upon his blog a while ago. Well considered design really nicely done execution - I hope he is getting lots of fun from her. Its bloody interesting this whole subject, and something I have dabbled in a bit with varied results. I think that the 6 masts 6 sails thing is a decent if conservative basis if you are going for an entirely new rig concept. You get to a paretos law situation ie the first 80% of results come from the first 20% of effort, The last 20, or realistically 10% towards perfection, whatever that is is the hard bit. Obv if you are just having a go at a sail only that is a different story. A good product for smod use will require a lot less finessing than getting last 1% performance in a development class. The effort for smod is in designing enough cost out whilst keeping sufficient capability. I think that if the sailor or owner of the process is either a sailmaker or engineer, the process can happen a fair bit quicker. Similarly if the sailor or sailors have a really keen engaged sailmaker/ spar maker on board (often but by no means always a function of potential earnings ) then that can significantly expedite things. if it's just a sailor or sailors pushing shit up hills with an Unengaged sailmaker/ spar maker then it's a bit of a case of how many monkeys with typewriters are needed to write the collected works of Shakespeare. These days some bigger lofts and spar makers have sophisticated software that can do coupled aero and structural calcs that can significantly fast track these sort of wholesale rather than incremental developments. In big boats they make a lot of use of that, but as you get smaller the cost of making prototypes becomes competitive. Of course as with all software, rubbish in rubbish out so somebody has to know what they are doing and what they are aiming for. Absolutely agree that if results on water are your primary concern leave all this shit well alone and cherry pick what someone else has done once it's mature and demonstrably better than what went before.