Saturday, July 12, 2008
testing
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).
Saturday, July 5, 2008
linkages relinked

Sunday, April 20, 2008
The States
1. out of control approaching the bottom mark. i was on the same lap as the scows.
2. at least i missed them.Friday, April 18, 2008
race ready but no sail today


Thursday, April 17, 2008
Done and dusted


Wednesday, April 16, 2008
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.
Tuesday, April 15, 2008
sucker!
im bagging everything form now on! something to bag, ill bag it. fibreglass, oranges... small animals... lock up your pets!


Sunday, April 13, 2008
working parts

a sigh of relief for the foils are done...
a few cuts here and a few holes there, a bit of sanding.
the rudder is strengthened almost to the centreboard spec, it will hopefully be strong enough. (in its defence it is 2/3 the area... your honour.) i made it shorter beneath the boat so its foil travels 60mm above the line of the centreboard foil, and out of its downwash. there will be a reduction of the torque on the gantry from steering and foiling high, and also it will help the foil ventilate in a crash and thus not snap. we hope. and since there is not so much rudder in the water when foiling high, it will reduce my tendency to jam the tiller towards me to bear off before crashing, as that little bad habbit was breaking things... well reduce it by making it pretty much ineffective. hopefully my new reduced friction centreboard flap will help in that respect too.

Now for the gantry. The QLD moth states and my deadline are fast approaching (we're inside a week) The gantry should take 3 or 4 days to put together so i may even be able to rig the boat before the regatta. ha! as if. I bought a vacuum pump off ebay today for $160 bucks, which i think was an ok buy, and its in brisbane too so ill pick it up tomorrow, get some tacky tape on monday and be sucking on monday night. in the mean time i need a jig to get the angles of the tubes right and get them glued/carboned together.other than that i need to fix the hole in the boat (i bought a clear bulkhead cap for it, stuck it on, but it was a tight fit so when i tested it after the sikaflex had dried, i realised it was squashed and the cap wouldnt screw in.) (try again timmy. Timmah!) I need to get my welding bloke to weld my little stainless gudgeon for the gantry lower attachment, i need to get a batten for my sail, and i need to make those fiddly little ball joints that attach the rods to the flaps.
and that is all.
Sunday, April 6, 2008
Bell Cranks and linkages
Anyway i got the bell cranks designed and cut out. All the linkage bits i pretty much thought up as i went along, though i had a vague idea of what i wanted; they definitely had to be bigger than before, and i wanted to minimise friction and slack as much as possible. The little carbon forks on the fibreglass rods I think were a good idea, easy to make, we will see whether they hold together or not. they look pretty tough anyway. My little stainlless threaded fork is an M5 turnbuckle body that i cut up, and took about 5 minutes to make with the grinder. The thread is done for you its great.
I also took the opportunity to finish off the cams and do the wand as well. The centreboard system is pretty done save a bit of bog and the ball joint on the flap. Im waiting until I've done the gantry before i cut the rudder to length and put its linkages together.


I checked the centreboad foil angle of attack today too (first time in the boat) and its what i wanted (good management more than anything i think!) between +1.5 and +1.8 degrees on roungh calculations. Much more than that and you start paying drag penalties, but form memory up to about that range you only gain 1% or 2% Cd but significant Cl.

Tuesday, April 1, 2008
It had a baby and then the baby had a baby.
What i am of course referring to is what is by now one of my favourite things to do; pulling a mould of something out of the oven and then pulling some nice looking carbon bit out of the mould. and intending to wait until it is cool to open the mould but not having the patience and getting burnt. and in this case dropping half the mould on my toe.
The oven sat on 75-80 degrees for 24 hours, last time it was summer and it all got a bit hotter, more like a solid 80-85. and the resin loves that, so consequently i haven't got the tesnile strength in the resin quite as good. and it has a different, dull pitch when you knock it. but its still ok. that coupled with the better lay-up and a couple of other dirty tricks i have up my sleeve (rubs hands together) should hopefully make this one not break. 

Monday, March 31, 2008
sandwiched
- First of all the T joint has no foam in it at all, just glue (sp microfibres). Last time it was foam and bog (Q-cells) with carbon strands in it, that wasnt enough.
- There is some diagonal carbon along the front and back inside edges in the areas of high shear stress - i just chuked it in there with a big glob of glue in the middle; the idea is that when the mould squeezes together it gets pushed to the places the glue is oozing out.
- you can see in the photo I integrated my carbon T-piece into the bottom surface, that pushed straight up into the foil and is encased in glue. hopefully there is no way in the world it will separate from the bottom skin, or pull out of the strut.
- Lastly i plan to further tie the leading and trailng edges of the foil together around the T joint area and the exit area by making carbon 'wet bolts', at about 30-50mm centres for about 250 - 300mm, to join the top and bottom surfaces. ill put photos of them up when i do them.


Also i cut my finger twice in the same spot with the grinder. first time with the cutting disk then again with a sandpaper disk. the second time it went straight through my nice fresh band-aid. I put a heavy glove on after that. When you wear a glove you might as well have a bit of wood for a hand.
Friday, March 28, 2008
waxed and ready


Came to the realisation that i should have wet out the flap hinge in position in the mould, and stuck the plastic spacer strip on it there too. now i have to glue it in with PVA, and glue the spacer onto it. hopefully the mould type PVA will stick it. I wasnt organised yesterday to do that, so it never would have happened, but for next time...
Also completed step 2 of the cams, ill see how they come out tomorrow. ill bake them with the foil so ill post a photo of the finished product. i think they will be ok.
The carbon is now cut out too. its such a shame to cut up those big perfect sheets, but you gotta grit your teeth and do it. and hope you get it right. the hull became a pretty good bench, at 21kg bare, i think it is almost better as a bench than as a hull. anyway thats a couple of projects down the track. Oh also i cut a hole in the hull that i really shouldnt have cut... more on that later.

Finally i just want put it out there and say thanks to Andrew and Scott at CG composites for being so helpful with the resin and reinforcements, bog, glue, and peel ply etc. and to Mel and Miller and David at Glascraft Marine for putting up with my crap. From those two places i've been able to get 90% of the materials I need to keep this project going, and some good sound (and patient) advice, which has probably been the diference between a semi success (so far) and a complete cock-up. also Bretts/Bunnings you're both wankers, though 'Tube Sales' at Yatala i like.
Wednesday, March 26, 2008
gantry mould, cams, foil prep
also laid up the T piece to tie the bottom plate of the foil into the T joint, and also the tang to attach the gantry to the transom (in the same mould.) mould looked cool i took a photo. The T piece i will drill some holes in, to make sure it bonds well to the bottom plate, also i will put a couple of layers of carbon over the top of it.
Did the hinge as well, had an interesting incident with the leftovers of my hardener-heavy resin (to make it a bit more flexible than normal) started smoking and actually boiled and set in the tin at the same time. must have been hot today.
Saturday, March 22, 2008
construction commences!
The foil is designed with some sneaky new improvements, and i have re-surfaced the moulds (they are a fraction more accurate to the NACA shape now) and added and subtracted aluminim strips as appropriate. The front edge of the foil is now 10mm forward of the strut, so that the rod has more leverage on the flap. I've stuck the moulds back together like before, so that all the angles are adjustable, using longer bolts this time, and the result resembles some kind of fusion beween a smoked chedder and a jarlsberg. lots of crumbly holes. whatever, they'll get covered in wax and resin anyway.
I've sussed out a (hopefully more effective) new rudder flap adjustment system using a piece of string and a cleat and some elastic/pulleys etc. we'll see how that goes.

