Buccaneer 24 Builders Forum

Paddy, will send a £1 for every multihull you can spot...

 

Weight and Balance

Like OS I am a lover of Aeroplanes and Aviation, as a child I would spend all my pocket money on Airfix Aeroplane kits, nothing much has changed except I now build and fly very large RC aeroplanes, although it does not take over my life now! - a heavy badly constructed aeroplane will fly if you get the CG correct, it will just need a long strip to take off and will be a unpleasant flight experience, a well built aeroplane lightly made with correct CG will give a much better flying experience, however problems still arise, a lot of RC flyer's are blistfully unaware of certain criteria and fly there aeroplanes in so called 'trimmed out' flight with a Tail Rudder offset or Elevator and Aireron's offset to compensate for the 'Balance' of the Aeroplane and restricting a nice even flow of air over the Airframe when all they need do is alter the angle incidence of the wing slightly and importantly balance the wing for CG, the port end or starboard end of wing will always be heavier than the other end and affect the way the aeroplane fly's, a balanced aeroplane will take off without assistance (depending on wind) and will almost fly itself.

The same theory and principal must apply to a light displacement small home built trimaran although it never comes up for disscussion - the B24 for example has a beam (span) of 19 feet -at the build stage the port and starboard floats will never weigh the same no matter how well they have been built because of density of wood, glass mat, glue etc and I can imagin in the rush to build the boat the builder will often overlook the fact that one hull is alarmingly heavier than the other (unbalanced boat), I have no doubt that a balanced boat (B24) will reward you with a small gain in handling and performance, some boats may be balanced, more by luck than judgement, I wonder how many builders go the extra mile....

 

balanced

John, my boat is about 20lbs out of balance (at the floats), mostly due to the offset 55lbs outboard. I can easily carry some equipment on the other side to off set it, but I really can't tell any difference when I am sailing. Just moving my seating position changes the trim more. Sailboats, unlike airplanes, are almost always loaded from the side, and small amounts of weight just don't matter as much. I could easily tell when my light plane was 5 gallons out of balance, but it takes 75lbs or more to effect the Buc. B

 

Hi Bruce, Im only talking fine tunning here and peace of mind if you are building a new boat, we do get familar with our possesions, we recently bought a wide screen television, I thought it was huge when it arrived - its just another part of the furniture now and I hardly notice the size. However I wonder as if by magic, overnight the excess weight was transfered from the heavy float to the opposite side, it might surprise you

 

Different creatures

I would be happy to do with out the extra 20lbs- actually, both of my floats are overweight by more than 40lbs-the decks have been re-built several times and the whole boat is constructed of 1/4 fir. However, a tri is not an airplane- on one tack (50% of the time) the 20 lbs is working for me, and on the other tack, it is only an overall weight dis-advantage, not trim. I don't have to lift the hull with the rudder, just my crew's position. The helm stays centered so the boat's foils are not out of trim. I do start the day with excess gear/sails on the "light" side- one sail or a beer cooler trims it out, by the end of the day, the sails have been moved and at least some of the beer has been "unloaded" overboard, and I can't tell the difference. (maybe too much beer?). In light air, about half of the steering, including tacks, is done with crew weight and once the floats start to load, total weight is all that matters in the real world. B

 

Here is pics of all Hull and Float Frames for the Buc 24.

I used 5 sheets of 6 mm Maine Grade ply 1088, carefully uterlising all available space, the weight of all my frames including the keel plates is a total of 18.5 KG, both float frames only weighing 3.5 KG to be deducted from the above.
Next stage will be to glue up wood edging, glue up keel plates to frames and fit stainless chainplates.

 

Nice work John.
Don't forget to put the edging pieces on the front faces of frame 5 forward and the back face from 6 aft, to take the chamfers for the sides and stringers etc:

 

Yea, thanks OS, it does state on the plans but can be very easily be overlooked.

 

6th

On the 6th picture on the bottom of the frame i can see the cutout for Stringers? but if I enlarge it there are some other cutouts drawn on the plywood about twice the size of whats there. What are these for?

 

There is additional stringers (one & quarter inch) each side of keel box.

 

Sorry diegokid I was looking at another picture, I dont quite understand what you mean -are you refering to the cicular cut out?

 

#6

Pic number 6 frame two. If you select it and enlarge it you can see some pencil marks just above where the cutouts are for the stringers, just curous if these are purposeful or one of my oops!

 

Diegokid, there will be lots of pencil marks, before I can cut the ovals and circules within the frames I have to mark the two and three quarter inch edging to give me datum lines, then I can get the compass out and join the lines, it is quite easy once you get use to it, hope that helps.

 

Nice frames

John, Those look very good. You should end up with a very straight boat. Accuracy at this stage really pays off. B

 

Bruce, thanks, I ought to mention, I have never done lake sailing in my life (may be Ive missed out) I have only sailed the coastal water's/area's of the UK and France and the English Channel, the ballast you mentioned in your last post would immediately be washed off the boat on leaving most UK Maina's.