Liftkeel Daycruiser re-engineered

[kitedancer]

Hi,

I decided to share my newest sailboat project here..
http://kanikoira.fortunecity.com/boat.html

I bought 5 meter long sailboat hull (without rig) some time ago. Now im converting it to easy going trailerable daycruiser.

It should become something like this..

Loa 5,0 m
Bmax 1,8 m
T 0,17-1,00 m
m 480 kg
Sa 13-18m2

Im using Maxsurf academic and some help from larsson & eliasson..

[kitedancer]

heres some similar boats that im using as models

microtross
http://www.vene-bjorndahl.fi/microtross.htm

joe17
http://www.paatti.com/joe17/vene/esite/index.htm

helmsman my / helmsman 20
http://users.tkk.fi/~otolvane/opt/eemeli.jpg
http://www.marnet.fi/gallery/venekuv...3_P1010300.JPG

and micro 550

[bart streb]

Are you reconfiguring the keel for a lifting foil? I am in the process of doing my homework on my boat. What Naca section are you going with?

[kitedancer]

I'm not quite sure yeat, but i think i go with naca 63- (or 65-series, or both) But i think that it would make some problems, if thickness changes a lot.

I think that im going to plain deep or elliptic keel with 65-009 (or thicker) on root and 63-009 tip. Or Make it simple and just use one section (63-series) tmax from 15% root to <9% on tip.

If keel planform area should be in my situation somewhere near 0,60m2, i could make (elliptical) keel with root chord 0,7cm, tip chord 0,3m and draft 1m (ar=2 and tr=2,3 , these are approximate). If i go with 63 series usign 21% thicknes i got keel with littlebit over 1m2 wettedsurface and planfrom 0,5m2. These are for plan straight not elliptic keel. But when going with 15% tmax root chord thickness wil be 10,5cm (=70*0,15) its fine. and with tipchord of 9% tip thickness will be 2,7cm. Looks nice. Volume approximate with ((15+9)/12%) 63-0012 shape is 0,017m3 and filled with steel it is near 120kg. With 65-series it would be little bit more

I hope that someone understood what i wrote..

keep it real! aloha!

[bart streb]

Hey, you are hiding something. You said you were converting it to a casual daycruiser. Why would a casual daycruiser need all those math equations for the blade!!!!
What kind of rig are you going to get.

[kitedancer]

Sure it would be easier to just go with plain centerboard (just like what was in it originally). But if i got a change to make that thing go faster and have better characteristics of course im going to do it.

Im noit quite sure what kind of rig im going to use. Maybe i use some old rig and try to use it (i got few complete (selden) rigs with basic sails, mainly from motorsailors, mast lenght 6-8m). But again, i think that rig should also look good (it doesnt look good if theres a mast with too large profile in small yacht) and work nicely. One thing is sure and its im going with sloop.. (suprise!)

6/7 part rig with ca. 8m2 mainsail with jib (ca. 7m2) and gennaker would look good. If

or 1/1 rig with smaller mainsail (without roach) and furling genoa (~12m2?).

.. depending also how much i have spare money! but sail area is going to be anyway between 13-16m2 with main and jib/genoa

[bart streb]

Would a Hobie 14 rig without jib, but including a genaker work? You can find Hobie parts around here cheap if you dig around a little. I am not sure what boat parts are easily available (and cheap) on your side of the globe. If you wanted to keep it "casual" and simple, I would go with a cat rig (just a main), then have a small bowsprit and genaker off of it for downwind. Depends if you are singlehanding most of the time or doublehanding, and your wind conditions. I bought a brand new North (ShriLanka loft) fully battened mainsail, 9m2, on Ebay for $138US. I would start getting the parts together now. It should be a fun project.