13 ott 2007

Center or dagger board ?

Maybe a poll is useless. In fact, doing my homework, I found these choices:

  • Centerboard: Menno, Oliver.
  • Daggerboard: Ed, Jay, Grant, Roger, Tor, Luigi.
I prefer centerboard, at present, "its offset case taking up less room in the cabin, plus it will kick back should it hit bottom". These seems good properties for a cruising program. Centerboard case seems a little easier to build, too.

Should I think the majority of you are building racing rockets ? Comments welcome, as always.

Deriva a baionetta o basculante ? Basculante ! Più adatta alla crociera. Ma per perchè quasi tutti la fanno a baionetta ? Pazzi per le regate ? Commentate, gente, commentate ...


6 commenti:

Grant Kinsman ha detto...

Hi Biol,
I'm not so sure the centreboard is easier to build. Plus you have the pivot pin down there to compare to a cheek block that is well above the waterline.
Good luck on your build and cheers,

Grant

biol ha detto...

Hi Grant,
the pivot pin under the waterline is a possible source of water infiltration, you're absolutely right; looking at F-22 appendix sheet H, however, it seems possibile to arrange things so to have the pin set from the OUTSIDE of the hull (pushing the pin in its place from right to left, in relation to the drawing), with the large washer welded at an angle to match hull side (it will be all "strong" putty, there around), avoiding any real "through-hull" hole.

Just an idea, there could be some drawbacks that I can't see now. A daggerboard really seems more pratical and efficent. Every choice is a compromise and it all dependes on how you give a weight to the various factors.

Many thanks for your comment ! Have a nice day.

Ed ha detto...

Reason I/we are doing a daggerboard...

1) There needs to be a mast support pole in center anyway, although smaller with the centerboard there, hopefully daggerboard case will find extra usefulness?

2) Mechanism more simple and hopefully less things to break. Although I like the idea of it pushing back should the ground be closer than thought, our current monohull has a centerboard and a portion of the pull-up mechanism is broken due to forces exerted. I realize Ian's design is more than likely MUCH stronger than this, but it's a source of prejudice.

Tor Rabe ha detto...

Daggerboard. I have a centerboard on Frimann and it sails very different on the two tacks. And the case really catch water when the speed is up. And the daggerboard I think is easier to build and maintain. And i will use it as a support for a table.

The extra space/less obstruction with the centerboard however seems beneficial.

Menno ha detto...

I'll often sail on shallow waters, so the centerboard was an easy choice for me.
Apart from that I would probably have chosen the centerboard just as well, as it doesn't use up precious cabin space.

For what it's worth: I'm not afraid the pivot pin, build to plans, will leak. Why should it? I wouldn't go into all the trouble to fix it from the outside.

Good luck building,
Menno

biol ha detto...

Thanks guys for your interesting opinions !

If it isn't there, it can't break: this is an aviation mind set, always favoured by Ian Farrier (about weight). But F-22 centerboard is not that complex ... I agree with Menno about cabin space.

Ed, I built a small 15' dinghy in 2001, plywood S&G, still working great; she has a centerboard and I like it. At speed water pushes to come into the cockpit but F-22 plans provide a baffle inside the cb case to avoid this.

Tor, maybe Frimann's CB is way more offcenter than in a F-22 ? Or she heels more ?

Thanks you all !