Composite Boatbuilding 1

Composite boat building.

For the posting with bigger photos, follow the link below.
http://yate.tistory.com/entry/Composite-Boatbuilding-1


1.Frame Design

Picture below is one of frames and explanation how we got it follows.

From the picture above, B is deck line and to get "a"(below), draw a dicretionary line A(above). Now distance between A & B(Deck Line) makes "a".

For b, all the frames from STN.5 to STN.15 has fixed value of 830(from C.L) which is longer enough so it could sit on C.

Those frames from STN.0 to STN.4 have values of distance between A & B(Deck Line) as "b".

And straight line connecting a and b(below) starts from CHINE level but there are some irregulars on STN.5,6,7.(They starts from under CHINE level and I don't know why but not important, I think.)

And draw a line under canoe body(In this case, the line is 470 down from CHINE) and then we get  enough space of frame to join. All frames have fixed value of 470(CHINE to bottom) but different values on CHINE to SHEER.

2.Frame Cutting

When we got there at workshop, only one frame was left to be processed through CNC(Computerized Numerical Control).

To get it processed through CNC, CAD file(.dwg) must be saved as .dxf(Not Sure!).

But, the machine we used is 3D machine and AutoCAD drawing contains only 2D information. It doesn't have any information on how thick those frames are. Q.So do we need to add 3D information? or ??

Video below shows how we made frame using CNC machine and it's quite noisy, be careful while watching.

CNC machine has vacuum holder and it changes its tools automatically.
When it's done, we make holes through its cut off mark and using router-looking tolls, trim and finish it.

3.General Outlook of the Boat(or Plan)
* LOA: 5500
* Beam: 2407(at STN.12)
* 16 STNs.(0 to 15)
* C.I: 366.66
* Sailboat with center board(no fixed ballast keel)

4.Setting Up the Strongback(Cleat??)

[Half Breadth]

If there's any other word to describe those woods(C) on which frames are set, please let me know.

Picture above shows Strongback plan. Frames from o to 5 sits on two angled beams and the others are on straight beams.

1st. Clean up the floor and surroundings.

2nd.Drawing Datum & other lines.

We need to draw C.L, Stronback(Either its center line or its outside) line and Station lines.

- Drawing Center Line using metal frame with straigh edge.
- Draw Strongback lines which are parallel to C.L and draw angled front strongback lines.
- Draw AP and FP
- Setting up two tape measures on straight Strongback lines.

* When we were doing "Dory", we used a tape measure and common interval altogether to reduce measuring error.(Settig up tape measure-->Mark stations using tape measure-->Mark stations measuring Common Interval from each station). But this time, Common Interval is 366.66 and its unmarkable with human eyes and hands. So we used distance from AP(or FP) to each station to mark station lines using two tape measures.

* And also using trammel arm, made it sure that it is perpendicular to C.L and Strongback line. But to use trammel arm to get perpendicular station line(Need half length of each station), we still need Common Interval, in which there are some discrepancies.

--> Since we are not using under decimal C.I and also impossilbe to use it, we measure each station using distance from F.P or A.P. From this, we can get C.I from it and it has slight discreapancies to make up under decimal values.
367 / 366 / 367 / 367 / 366 / 367 /367 / 366 / 367 / 367 / 366 / 367 / 367 / 366 / 367  . So use this value to get perpendicular line, altogether with distance from F.P(or A.P).


3rd. Cutting Strongback

 

4th. Fixing Strongbakc to the floor

Since we decided to use "no more nails" on the floor, we used adhesive called liquied nails and it's just like using silicon sealant gun. Before we glue center piece of Strongbakc, if center line is marked on the piece, that would be much easier for later job.

 

5th.
It's taking approximately 24 hours to be completely dried up and need to put some weight on the Strongback. And also if we knew about the position where diagonal brace would be jointed on the floor, we could glue it altogether  but we did it later.

  
5.Frame Joining.

While they were working on Strongback, the other group were working on joining the frames.
1st. Gusset Cutting.

Gusset is name of the part which holds frames together.

  
We made all the gusset all 500 width(length) with differnet height depending on its frame.


2nd. Joining Floor Setting.

  

We did clean up on the floor and set the kind of bonding jig using two straight metal frames. Those two metal frames must be joined(met) at right angle. To make it sure, we used metal square rule and Pythagorean theorem which Chris told us about. But it turned out that we screwed in joining. There were consideralbe gaps between frame parts and screwing position was not proper.

So the next day, we tore apart all the frames and did it again. This time, we added more wood block(stopper) on two metal frmaes so that it doesn't move at all, used human weight on frames to hold it firmly and moved screw  position.

  
While we were joining the frames, we could do it well organized way. While some of us were gluing and screwing and the other were sanding the surface and set it in order and so on. So there was no time wasted, I think.