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.

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

been out sailing a couple of times since the lake

the boat is getting better and better. the foil mods were aimed at reducing induced drag when the flap is fully deflected, and do seem to give a smoother accelleration at takeoff. the wand system is getting better fast, with my bendy bit of aluminium allowing for the whole thing to be mangled on the water. ive taken all the slack out of it and i now get that bumpy feeling when the boat is going quick upwind, and have a greater range of where i can sit.

my dodgey skin fitting rudder adjuster works a treat as well, after a bit of WD40! ive also managed to reduce a bit of friction everywhere (hello wd40 again!) and im now almost at bladerider standard in this department.

the flap hinge incorporated into the laminate has started to crack and distort, and im not sure ill do it agian. if i do, ill use something different. the problem is you cant replace it when it gets a bit shit (if this one gets worse, ill cut it off and do a sikaflex hinge)

its now obvious that the boat is too heavy, too leaky, and the foils are too square. time, it seems, for a new boat!

allboats

lake cootharaba is getting a bit too shallow. the long walk out to the middle to get on is getting too long. and then you get the boat up and get on and you're sitting on the foils on the bottom, i ended up just sitting  back dragging them through the mud until i was up and going, then trying pretty hard no to crash. and repeating this procedure after every tack.

aside from that the boat went well, and improved over the weekend. in 10 - 12 or more it goes fine around the course. in less than that i can foil on reaches and sometimes upwind but not really downwind, and i cant point. since the setup is getting close to good, i'm starting to blame weight, 'square foil drag' and 'fat ass hull drag'. these are things that wont be fixed with tuning, though i plan to make a few changes to minimise 'odd shaped gantry drag' and 'poor sailor finesse drag'. also im getting the pocket in the sail adjusted to my mast, which may hopefully pull some draught back in the sail to line up with my aft centreboard case. i think that may give me some more height upwind. 

anyway that said i had moments of glory; like picking through a fleet of A calss and nacra 5.8 cats on a reach in 10 kts. or beating sharpies and MGs around the track in breeze, despite my shit upwinds.

on the way home some tired dude ran up the back of the trailer in traffic on the highway, doing about 20ks and we were stopped. missed the gantry (that hangs 600mm over the back of the trailer) by centimetres, broke some lights and stuf on the trailer and sheered the bolts connecting the hitch on. so while his car got put on a tow truck with some pretty severe facial modification we sat on the side of the highway wondering how we were going to get 3 M12s to get the trailer back together and get home. anyway long story short his dad rolled up to take him home, turned out he worked with my dad, (brisbane is small) so they went off on a mission to get bolts leaving me and the tired dude who'd just nearly written off my boat to make small talk for an hour on the side of the highway. fun times.

sailing

went out for a sail in gusty 15 kts with Rod from the gold coast. the boat went ok, though the flap response is still not adequate despite all the improvments. i need another change of wand to a bladerider style thing with a substantial flat bit on the end, that will pull it back propperly. also the straight wand is the way to go.
had a go on Rod's bladerider, and doesn't that make it obvious that my boat is underperforming! you just sheet on, point it, it pops up to the right height and accellerates endlessly, without spontaneously launching out of the water, tipping over sideways or sinking back down. i think i hit over 20 on his velocitek, though it may have been lying. the linkages on his boat were working overtime, while mine were kinda stopped, lethargic. it was interesting to see my boat being sailed well by someone else also, and i know a couple of things. it can go quick upwind when sailed propperly, though probably not in less than 15 kts. It looks really bulky when foiling compared to all the other boats. its like the fat kid.
resolve to put it on a diet. failing that a new hull/wings.
new bladerider sail is an improvment, needs slight luff adjustment.

wand

i did a couple of maths and realised that some of my light-air trouble is possibly stemming from my technique, rather than from setup problems. (would be great if it turns out this is the case.)

Basically when i sit at the back of the boat and try and launch, i can get up to about 7 degrees angle of attack on the centreboard foil as the bow lifts up, and my boat's fat ass drags in the water. lifting off like this the wand starts moving the flap up, as the front of the boat starts to clear of the surface. in this configuration, with the flap down say 5 degrees out of 20, the centreboard Cl is 1.57 and Cd is 0.0193
If on the other hand i was to sit really far forward and keep the nose buried, i could keep the flap at say 15 degrees down, at the same stage of takeoff. in this configuration the centreboard angle of attack is 0 degrees, but with the extra flap deflection im still getting a Cl of 1.54 and a Cd of 0.0156. so this is better, same lift for about 80 to 85% of the drag. ill try it out on the weekend.

also i ripped off my crappy wand. finally. i laid up some new bits tonight that will allow me to adjust everything about the wand, and to use carbon rod and tube of varying stiffness and size. I have a choice of two wands to start with - a straight stiff one with flexible tip and a kinked, stiff one like the old prowlers, with a flexible tip as well. ill try both on saturday weather permitting. The aim of all this is to keep the flap at full deflection while the bow is within a foot of the water. the winning wand gets glory. and to stay on the boat. it is possible that they will both lose, in which case shame will be brought apon their families. and they both also die.

testing

went out today for a few hours to test the new modifications. conditions were like 3 to 12kts. anything above about 8 i was foiling, though probably needed 10 to go upwind and downwind propperly. everything worked well, no breakages, nothing moved at all. didn't capsize or crash, but i was playing it pretty safe. tried a foiling tack and almost threw myself off the back corner of the wing, holding onto the tramp lacing with my feet. it turns much quicker on foils!

The linkages work much better, and the rudder adjutment in particular is a massive step up from what i had. the wand vibrates when going slow, which is annoying, so ill take to it with the grinder and make it flatter on one side. also thinking about a flat surface on the end, so that not as much of it drags in the water.

i need a new sail.

im not quite happy with the angle of the centreboard. i noticed that i had the rudder trimmed back, flap up about 5 degrees, to the point where half the time it was actually pulling the transom down; you could see because the top gudgeon was touching the top of the gantry, rather than there being a small gap. seems to me the rudder foil could be smaller. before i go cutting stuf im going to make an F-box of sorts, a contraption that lets me adjust the rake fo the centreboard over about 5 degrees on the fly. also i want to put a small bulb at the T joint of the centreboard, to hide a wad of carbon uni that i will wrap around the leading edge at the T. the crack didnt get any bigger, but im not going to risk breaking this foil. so there's 2 or 3 projects to keep me busy(er).

linkages relinked

just a quick note: the boat is nearly back in one bit again!

all linkages are now stainless, after much swearing at (breaking of) expensive taps/dyes. there is less slack and the ends are more robust, especially the new flap joint which is a beast. see below, pretty self explanatory. i think the bladeriders have a similar thing, with the benefit of having a nice thick bullet fairing to hide all the shit in. i reckon ill have to fair it a bit.

the main foil appears to be at a good angle to the static waterline, about +1.5 to +2 degrees; i think the flap was just jamming in the 'up' position after the linkage broke within 10 seconds of leaving the ramp, giving me that 'sucking' feeling. also theres a 10mm long crack at the t joint of the new centreboard, not sure if its superficial or not. im keeping an eye on it. be sailing soon, should be interesting.

The States

Im not actually on the same lap as matt...

1. out of control approaching the bottom mark. i was on the same lap as the scows.

2. at least i missed them.

well I finised two races, and in one of them i beat another boat.

Had a couple of teething problems as you do when your that unprepared at a regatta.

Saturday was a bit of a write-off, as it was squalling through at 20-30kts as predicted. there was one boat in a fleet of 11 which did not sustain any damage, and that was Matt with his bladerider. He sailed the boat pretty damn well for the conditions. The sheer variety of damage seen on the rigging lawn after racing was abandoned was impressive even for a moth regatta. I lost my rig, and in the process busted a panel in my pretty shagged sail. (fixed with gaffa tape) The foils were fine, but they were probably to blame for the whole 'losing the rig' caper in the first place.

I have somehow managed to stuff up the angle of atack of the centreboard, i think. There isn't enough +ve angle, which meant i wasn't getting up and foiling at the kind of low speeds i should be able to. I will fix it by increasing its forward rake, which in the long run isn't a bad thing. This means i need to modify my centreboard case thing.

The rudder adjustment systems is shit. needs a better sollution.

Both ball joints failed on saturday, and though i tried to fix them with 5 minute epoxy, they were too loaded up and snapped again within minutes. So i sailed Sunday with no flaps at all, and it was predictably hard to foil and hairy once up. I have a new 'bladerider inspired' sollution, which should work or at least look a bit pro. Means ill have to go back to stainless rod for pushrods instead of fibreglass. no big deal.

Anyway, for the next month or so I've got a bit on at uni, probably not much will happen on the boat. After that ill sort out a new mast and sail, and get to work on the few things to tune before i go sailing agian.

race ready but no sail today

its 30kts from the SE today. had a couple of odd jobs to do, could have dropped the boat down to the coast today and got a quick sail in but i decided it wasnt worth it. probably better to get some uni work done. Rigged it up as best as i could in the garage to make sure the flaps worked etc. they did, here are a couple of images.

Done and dusted

Dusted figuratively not literally. The dust will blow off on the highway tomorrow.

Missing one tripple block on the cunningham, ill have to get that on the way. The forecast is for breeze, 20-30kts, i am dobtful whether the boat will last the weekend and more doubtful about the sail. (now largely just gaffa tape) However i haven't fixed the low-rider rudder so foiling it is, and theres no backing out. The boat is literally rough aroud the edges, and obviously underprepared, but pending the success of the ball joints on the flaps (curing now) i'd say all the systems are go. [im liking this motif of using cliches in their original context] The adjustable gantry looks pretty good, though i realised why everyone else's have only one lower strut and not two; there needs to be some flex in the joint between the strut and the bottom gudgeon to facilitate easy adjustment. anyway its fine for now, hopefully i've got the angles right and i wont need to adjust it. The cams seem to work in the sail, ill wait and see on that one as well. i have a spare just in case.

gantry done pending 12 hours @ 80deg.

The release went well from the mould, by my standards. (lucky i didnt spend too much time on the mould.) The vacuum finish is impressive, the part is actually lighter than my previous gantry and 200mm longer. and intact. yay. at this point i declare the design to be good, and the construction to be good. lets see how we feel after a couple of sails...

The ball joints on the other hand were a complete failure, i tested them with a good solid yank and they came off. will swage copper ones tomorrow. also got the rudder gudgeons on. 6 jobs to go.

sucker!

My $150 ebay vacuum pump came through with the goods!
im bagging everything form now on! something to bag, ill bag it. fibreglass, oranges... small animals... lock up your pets!

yeh anyway so i had a couple of small issues getting it to work, seeing as it was my first go, and the job was quite complex. i think that box was the most complex thing i've ever laid up; it had lots of different ingredients and was awkward to get your hand into. My main problem with the vacuum was in the spikiness of the mould. You wouldn’t think so hey. The spikes, nails, bits of glue/bog etc made a couple of little holes in the bag, and i tried patching them up with tackytape. Didn’t work, so i got a whole new bag (garden strength garbage bag) and put the whole mould and bag in that. Taped it up. sweet.

Carboned up the other bit of the gantry, the two tubes. Also stuck some little globs of glue in the exact right places on the control rods in the foils to serve as the balls in my flap ball joints. Got the stainless T piece welded also, thanks to Rod at Astro Metal for being a good bloke.

8 things to go on the list.