Sunday, November 16, 2008

the next iteration:
bow higher, aft deck convex, aft wing struts... strutting, gantry (not fully thought through) more kingpost rake to resist max loads (12 deg), decision made not to slope the transom because i couldnt get it to look cool (tiny transom anyway, might revisit this) tramp not updated re. filling holes slightly.
Still not sure about the volume / freeboard, im inclined to thing there is too much at the mast, (450mm to top of deck) yet to measure a bladerider for comparision.

the rest of that foil article

Heres the rest of that article. 80s gold.
Aso i just want to put it out there.. i have hinge damage...

Though i have yet to lose the whole thing on foreign soil, this moderately irreparable cracked hinge may be something that we will be seeing more often.

Tuesday, November 11, 2008

foil article

heres something i just stumbled apon when flicking through a 1983 issue of Australain Sailing. may explain why some people have massive rudder ventillation issues and I dont seem to. my rudder is a 66012 as opposed to a 0012. bring back decent sailing journalism!

new stuf (hull, wings etc.)

so ive been neglecting this for a while, mainly due to another architecure folio.
been sailing a few times, but mainly been in front of the computer evolving into one of those hunched, pale, widescreen-format-eyed little creatures (from the future).

anyway the whole time i was studying i was sidetracked with a stack of new ideas for a moth, and im pretty sure ill be building something over the summer "break". The lines are from Doug Culnane's Lord Flasheart, designed in collaboration with Adam May. (cheers doug, looks great)

Flasheart is available for home builders like myself to have a crack at, so in the interests of total tansparency ill be chucking everything up here form design to eventual completion. that puts the pressure on to not fuck it up i suppose.

construction will hopefully be by female mould, cut from high density foam using a 3d router. dont know how much that will cost yet, but the plan B is a hot wire and ply plug. the boat will be built in 2 halves, vacuum moulded etc etc. the aim is to keep construction extra simple and quick so that the thing isnt still half finished in a year or 2. kinda defeats the purpose. 10kg for the hull will be acceptable, but i will of course be going for lighter. as this is my first go i want to make sure it holds together.

what the wind 'sees'

there are a couple of odd ideas in this. this is only the first iteration, i might do a few versions with different configurations to get a feel for what will work best, be lightest and cheapest. I'd love some feedback on what you think will work and what wont. at this stage i think its better to get a bit of consensus on things. The main decisions i've made with this one:

  • Foredeck, wavepiercing bow - The stem is even shorter than Flasheart, which is on the short side as it is. im hoping that the bow in this configuration will go further underwater without digging in, and use the buoyancy around the mast base to pop back up. i find that most of my stacks at the moment are due to the drag of the foredeck, tramps and ropes stopping the boat, rather than the pitch.
  • Kingpost, Recessed foil wingbars - The foil shapes are mainly there to reduce fricion when the hull does go under a wave, though they should reduce windage a bit too. circles are terrible in terms of drag and im avoiding them as much as i can. The kingpost is cantillevered from the keel, so there is no need for a forward support, that adds areodynamic and hydrodynamic drag. ill make a bladder mould for the kingpost, so i can cantrol the fibre orientation and reinforcement.
  • Wings - Raised up and out of the way of everything. the freeboard is slightly lower than flasheart aft, (50mm) the wings are slightly higher. They are airfol shaped, only because i think it would actually reduce drag a bit. it opens up a big gap between the tramp and hull which will reduce windage.
  • Flare - I altered the bow of Flasheart a bit to include a 10 - 15mm deep step. for lift.
  • Centreboard is 100mm further forward that Doug had it - his was in the same place as my current boat, on which mast is 200mm further aft. what is a standard dimension these days from transom to front of centreboard case? assuming 8 degree strut rake.
  • the outside wing bar continues aft of the back wing bar. the joint is easier, and you reduce tramp area, while still having somewhere to sit. and if i find the back bar is too far forward, i dont have to buy new outer bars.
  • There is only one internal bulkhead at the centreboard case, which is pretty small. (divides in 2 as per rules) some diagonal reinforcing will be built into the hull laminate.

anyway the only things i am sure about at this stage are the general freeboard, and the step in the chine.. foredeck could come up, aft deck could be convex (better for 3d router). wings could atach to the hull (i feel it may be better to have something solid to stand on, rather than just tramp, though this means reinforcing the deck a bit?)

anyway ill keep plugging away, please email me if you have any ideas