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by '81 Hobie 16 Lac Leman. 03/31/24 10:31 AM
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Re: BITZA F16 [Re: Mark P] #191582
09/22/09 07:27 AM
09/22/09 07:27 AM
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Spot the difference in the "bow on" shot to a normal hull

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Re: BITZA F16 [Re: Tony_F18] #191583
09/22/09 07:33 AM
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Originally Posted by Tony_F18
The bottom gantry doesnt look as strong as the top one, not that I know anything about building though.

The Stealth rudder stocks have no " beaching " safety mechanism so the lower bracket has a " weak point " which I hope will break first should I clout something in the water at speed. The same section is threaded to allow adjustment of the foil. Any vertical stresses are taken by the upper more beefed up pintle.

Re: BITZA F16 [Re: waynemarlow] #191585
09/22/09 07:47 AM
09/22/09 07:47 AM
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No dings or scratches from hitting rescue boats hidden behind Committee boats?


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Re: BITZA F16 [Re: Mark P] #191590
09/22/09 07:54 AM
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Ah no wrong reply but I bet after about the first 5 minutes of my sailing, you won't be far wrong. laugh

Re: BITZA F16 [Re: waynemarlow] #191599
09/22/09 08:11 AM
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Originally Posted by waynemarlow
Spot the difference in the "bow on" shot to a normal hull
Split forestay attachment way back on the hull to give as much space as possible to the spi so it can fly to either side from its under tramp position. Do I win?

Re: BITZA F16 [Re: waynemarlow] #191600
09/22/09 08:14 AM
09/22/09 08:14 AM
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Then it's got to be those special knots you use, you know the ones, only come apart when you least want them to. I still remember Grafham 2006, first race just started and within 30secs a big splash.....good knot Wayne. I guess you don't use them on your traps anymore! chuckle, chuckle grin


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Re: BITZA F16 [Re: pepin] #191604
09/22/09 08:19 AM
09/22/09 08:19 AM
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I think you're really close Pepin but I think it may have something to do more with the spi pole?


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Re: BITZA F16 [Re: Mark P] #191608
09/22/09 08:23 AM
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No, just to do with the hull, yes the splash was embarrasing to say the least blush and I couldn't blame anybody else. Since learnt to read manufacturers instructions better.

Re: BITZA F16 [Re: waynemarlow] #191612
09/22/09 09:26 AM
09/22/09 09:26 AM
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Nice job Wayne!
Noone seems to have commented on the daggerboards being canted the 'wrong' way to perceived wisdom?
I think you're onto something there though as there will undoubtedly be some lift generated with that setup that should help in reducing drag.......
Have you done any theoretical calcs at a range of speeds?


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Re: BITZA F16 [Re: Jalani] #191671
09/22/09 02:40 PM
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Originally Posted by Jalani
Nice job Wayne!
Noone seems to have commented on the daggerboards being canted the 'wrong' way to perceived wisdom?
I think you're onto something there though as there will undoubtedly be some lift generated with that setup that should help in reducing drag.......
Have you done any theoretical calcs at a range of speeds?


Eh????

John, I see them canted in (so tips are closer than the top); Standard in the A class fleet.

Wayne, are they "true" in the hulls; some A classes have them slightly toe in to create even more lift.


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Re: BITZA F16 [Re: pepin] #191686
09/22/09 03:59 PM
09/22/09 03:59 PM
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Or is it that the forestay attachment is mid-deck?

Re: BITZA F16 [Re: waynemarlow] #191688
09/22/09 04:05 PM
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Originally Posted by waynemarlow
Spot the difference in the "bow on" shot to a normal hull
I give up. I can't see anything of note.

Maybe the hull is slightly asymmetrical on top? But I doubt it, it's probably an illusion from the angle of the shot.

Re: BITZA F16 [Re: scooby_simon] #191690
09/22/09 04:06 PM
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Originally Posted by scooby_simon
Originally Posted by Jalani
Nice job Wayne!
Noone seems to have commented on the daggerboards being canted the 'wrong' way to perceived wisdom?
I think you're onto something there though as there will undoubtedly be some lift generated with that setup that should help in reducing drag.......
Have you done any theoretical calcs at a range of speeds?


Eh????

John, I see them canted in (so tips are closer than the top); Standard in the A class fleet.

Wayne, are they "true" in the hulls; some A classes have them slightly toe in to create even more lift.


Mmmmm now that is an interesting question, I tried to get them as neutral as possible but it is really difficult as you are no longer just pointing the dagger board in one axis and without really good optical equipment it is sort of an educated guess. I have left the dagger board cases quite big to enable a bit of shimming if I have to and my guess is that my sailing skills are such that it will be pretty difficult for me to really tell until some way down the line.

Re: BITZA F16 [Re: bobcat] #191692
09/22/09 04:11 PM
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Originally Posted by bobcat
Or is it that the forestay attachment is mid-deck?


Good guess but not the one I was thinking. Keep guessing for the moment boys and girls, its not such a biggy but something I wanted to try.

Re: BITZA F16 [Re: Mark P] #191706
09/22/09 07:11 PM
09/22/09 07:11 PM
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Awesome, Wayne. Looks like Bitza will be on the water before Russell.


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Re: BITZA F16 [Re: TonyJ] #191713
09/22/09 09:16 PM
09/22/09 09:16 PM
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no self tacker...

what do I win?


Re: BITZA F16 [Re: ncik] #191724
09/23/09 03:48 AM
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No its not the self tacker that has been left off ( no good to a single hander and this boat certainly doesn't have the volume to be anything other than a single hander ) but something far more unfashionable.

I left the bow vertical unlike the very now fashionable raked back " wave piercing " bow that we now see on most F16 designs. At the time of building the hulls I had been breaking the Sprit wires at the front due to a very high and long angle back to the forestay that the early Stealths came with ( the later ones have the mounting point much lower down on the inside of the hull). Tremendous pressure was obviously being placed on these wires and by consequence the hulls. Proof of this was one of the Stealths at the club was showing deformation of the hull just in front of the beam. To overcome this I moved my Stealth's sprit wires as far foward on the bow as possible to get much better upward angles and thus less tension from the Spinny. Using the same diameter D12 I haven't had any break since.

Now we can either rake the bow back, put a lot of carbon and reinforcing in the hull to take the increased loading or we can move the mounting point as far foward as possible by leaving the bow almost vertical, I choose the latter as unless you are doing about 30 knots the true wave piercing bows simply do not work. I do understand why we narrow down the top part of the hull but it has nothing to do with wave piercing. smile

Would I do the same if I was building another boat, nah raked back bows just look so much more ubber cool cool

Re: BITZA F16 [Re: waynemarlow] #191725
09/23/09 03:51 AM
09/23/09 03:51 AM
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Mark P Offline OP
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It's obviously not a biggy cause non of us can spot it!! It appears to be a fairly normal bow to me but in good condition.
Have a look at this photo and see if you can spot the mistake, this is a little easier for us but a bit more embarrassing for Wayne.

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Waynes rigging!.jpg (1211 downloads)

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Re: BITZA F16 [Re: Mark P] #191726
09/23/09 04:17 AM
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Oh now Mark that is so mean. blush

Re: BITZA F16 [Re: Mark P] #191727
09/23/09 06:11 AM
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Originally Posted by Mark P
[...]Have a look at this photo and see if you can spot the mistake[...]
The mistake is obviously the fact that Wayne is using a purple spinnaker...

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