Lofting Blog 1: Lofting Schedule - Wei Shi's blog

Lofting Blog 1: Lofting Schedule - Wei Shi's blog: Today is the second day of our lofting training. In the morning, Chris discussed about the lofting schedule with us. A lofting schedule shows the process or the code of the lofting. The following is the lofting schedule for the dinghy (actually, this schedule can be applied to lofting of any boats, as a good lofting schedule changes little)

Table of offsets

Grid

Sheer - P

Deck Line - HB

Chine - P

Canoe Body - P

Stem Face - P

Chine - HB

Butt 200 -P

...

As I finished the grid yesterday, I started to draw curves this morning. Following the steps of the lofting schedule, I can easily find out what should I do now and what to do next.

Picture below: Lofting Schedule

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Review of Oilstone Box - Wei Shi's blog

Review of Oilstone Box - Wei Shi's blog

The oilstone box is the second project of the 'box series' (well, the first was the toolbox project). From my point of view, the process of making the oilstone box is much smoother than that of the toolbox. Everyone already knows how to use those machines and how to process the work with different tools.

The first step is preparation. Everyone got a plank with the length of 630mm. D4S the plank by using buzzer, thicknesser.

The second step is to mark out according to the plan.

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The third step is the real challenge. We need to make an inset in the middle of the plank for the oilstone. The plank was drilled and chiseled. However, the process was really difficult, especially for the chiseling. It is easy to chisel a hole in the middle but difficult to chisel a straight line at the edge of the inset. More over, the side and surface of the inset are very rough, it is even more difficult to smooth them. It took me almost the whole day (Monday afternoon and Tuesday morning) for chiseling the inset and frankly I am not satisfied with the outcome. Another challenge for the inset is that you must make sure it fits the oilstone. But the two sides (the black side and the red side) are not the same size, and the dimension of the stone is not exact the same as the plan. At first, I made the inset in the bottom according to the size of the small side (red side) of the stone, and then I found it was too small for the black side. So I had to chisel the inset bigger. Finally, I got the right size for the inset: make it a little bigger than the oilstone. After all, the biggest problem is not that you can not put your oilstone in, the biggest problem is that you can not get your oilstone out (if the inset is just the size of the oilstone, the stone may get stuck and difficult to get it out)

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After finishing the inset, plane was used to make bevel of the top of the box. This was my first time using plane to make the bevel. Thanks for Chris and Vaughn for showing me how the use the plane.

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The final step is to make the hollow at the bottom. This is even harder than the inset. I used bandsaw, chisel and spike shaver and finally I got the shape of the hollow.

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This is my finished oilstone:

Posted at 08:58 AM | Permalink

16/08/2010 First day of lofting - Wei Shi's blog

16/08/2010 First day of lofting - Wei Shi's blog: "Today is the first day of our lofting training. Well, have to say that lofting a boat in its full size (even it is only a small dinghy)�is very interesting, but at the same time, it is very exhausting as well. The first impression of lofting is that every tool used is super size (see the picture on the left). Everyone got a big cut board whose dimension is 4000mm x 1250mm. I have never drawn on a board of such big size.


After discussion with Vaughn, we decided the location of the LWL for the profile and the CL for the half breadth. LWL and CL are those first to be drawn on the cut board. Stations are the next. Drawing stations are quite tricky, and you have to be very careful about the error of every station line. Because the sum of the error of each station might be quite big. Actually I got 5mm longer of the Loa. And it took lot of time and effort to fix it.�Can not imagine how it will be to loft a big yacht with 21 or more stations.

After finish the LWL, CL and stations, I started to draw the sheer according to values in the table of offsets. But Vaughn stopped me and told me that the right order is to finish the grid first. This does make sense.�Then I spent rest of the day manipulating those big tools to draw water lines and buttocks."

Blog for Lofting - Wei Shi's blog

Blog for Lofting - Wei Shi's blog

In order to construct our e-portfolio for the lofting, we need to write 5 blogs which will represent five major stages the lofting training. Heading topics for these 5 blogs are:

Lofting Schedule

Lines

Stem

Angled Transom

Caculation

Picture below: Chris explaining blogs for lofting:

Small Craft Building: Week 3

This week is a short week, only two working days due to the labor's day (Monday).

Tuesday
1.Finished the scarfed transom and glued two piece together

Me scarfing the transom parts

Jade spreading glue on scarfing surface of transom

Gluing the transom

2.Started to bevel the frame

Two methods for measuring the bevel degree: first, use the sliding bevel; second, use a wood block （Vaughn showed us this method, and we found that this method is more convenient and easy to use)

Video: Using sliding bevel to measure frame bevel

3.Fixed one of those two laminated midship section
We found that our laminated midship section is not thick enough. We need some add-ons at corners. We use the cut offs of the laminated section, and shape them according to the shape of corners, then glue them together. Finished on midship today and will continue to fix another one tomorrow. Anyway, at least we can work on half of the boat tomorrow while waiting for gluing another one.

4. We decided to move our blog from typepad to blogger. And we will use Google platform (including blogger, Google docs and Buzz) for our teaching and studying communication.

Wednesday
Yesterday was really an intense day. Because several technique and skill problems had been discussed and solved by consulting with Chris and other team (thanks for Chris, Greg and James for their help and explanation on several issues), our task is to finish these components, including midship section, beveled frame, angled transom and the stem.

In the morning, the blade of band saw broke when I was cutting the stem. Then Sebastien, I and Tian replaced the blade with a new one (of course with help from Chris, the tutor as we were not sure how tight should the blade be).

In the afternoon, we assigned different task to every member of the team in order to accelerate our work.

I beveled the frame (lover topside), and next week I will finish the upper topside as well. Jade, Sebastien and I also used band saw to cut the bottom. And Sebastien and I beveled the edge of the bottom and make it exactly the size.

Lower topside beveled

Sebastien worked on the midship section. He planed the component to the exact shape according to the frame. However, he beveled one corner of the midship section off. Well, this is not a problem. We found a off cut of our laminated midship, and glued it to the corner to make it up. But we have to wait until next week to finish this part.

Sebastien shaping the midship section

Jade processed the stem, and draw the bevel lines according to the stem detail in the plan. It is really amazing that everything in the plan can be transfered to the actually processing stages. Take the stem as an example, you can transfer 2D drawing information to the real stem.

Marked stem ready for bevel

Kenny and Tian worked together to set up the frame to hold the angled transom.

Extra:
1. Chris talking about side planking:

2. Chris showing us how to sand the scarfed bottom:

Small Craft Building: Week 2

This is the second week of our small craft building program. In this blog, you can find following contents:
- Review of the week 2 (video included at the end of the review)
- Looking forward to week 3
- Extra: Using Router to make the fillet edge of the laminate midship section (video) and marking gauge (video)

Review of the week 2
Monday
The first task finished on Monday is to glue the laminated stem,as last week we already fixed the stem to shape it.Vaughn showed us how to make the glue. Get yourself a icecream container, and then you can start to make glue: first, mix two liquid following the proportion of 1:5 (this is already set by the machine, so you do not have to worried about it, just push the pump and get what you want). Then, you mix the liquid from corner to corner until they are well mixed. After that, put powder in, and mix again. Notice do not put too much powder, it may smoke. Once you get your glue, you can start to spread it on those lamina of the stem.

Shaped Stem

Making glue

Jade and I spreading glue on lamina of the stem

After finishing spreading glue, we put all lamina together and use cramp fix them on the board again.Use hammer ( you do not want to crack any of these lamina, so when you hammering, use a piece of wood the protect them) to make all lamina flat. Then all you need to do is to wait for the glue go hard.

Laminating the stem

Hammer with a piece of wood

In the afternoon, we just draw the cutting plan on the wood from which we will get our skegs, thwarts and gunnels.

Tian and Kenny continued working on setting up frames.

Tuesday
We tried to cut the dory's bottom and transom out of the plank. According to the plan, the plank is really full used. Some of edges of transom and bottom are so close to each other, there is no enough room for the blade (another team, Hory Dory, does not have the same problem, as their plank is little bit bigger than ours, they have enough space for everything).It took us lot of time to figure out how to get everything we need from the plank. Chris (tutor) came and helped us for the planning. As the size of the plank is not big enough, he suggested us divide the transom into two parts, and scarf them. Then this solved everything (at beginning we thought we should strictly follow the plan and should not divide transom into two parts, hehe). Notice that you should leave enough space for the forward part of the bottom side for scarfing.The ratio for scarfing should be 1:8 (the ratio can be 1:6, 1:12 or sometimes even 1:4, in this case, the ratio is 1:8, which means that as the thickness of the plank is about 12mm, we should have 76 mm longer for scarfing)

Cutting plan for bottom and transom on the plank

Two parts of the bottom side

We also cut lamina for midship section. Steam them soft and shape them according to the plan. Later in the afternoon, Tian and I glued one of the midship section as another one needs more time for shaping, so we decided to leave it for Wednesday.

Wednesday
In the morning, Sebastien, Tian and I finished glueing the second laminated midship section. Kenny and Jade was working on the bottom side scarfing.

Kenny working on scarfing the bottom

Chris showing us how to use plane to make the scarf

Finished scarfing (Good job! Kenny)

After finish the scarfing, we need to glue these two parts get our bottom. The glue is the same used for laminating but without powder. And we need to spread glue on scarfing surface twice. The second time spreading glue should be when the first layer of glue become little bit hard.

Me spreading glue on scarfing surface

Putting two parts together is a task that requires skills and experiences.Film is used to prevent the holding wood being glued with the bottom. In order to make sure that the bottom parts are glued strong enough, we first need to crump them on the table), then, use some long sticks (see picture below) to keep pressure on the scarfing surface.

Crump parts so they do not move side to side

Carefully place the film

use some long sticks to keep pressure on the scarfing surface.

Looking forward to week 3


Extra


Using Router to make the fillet edge of the laminate midship section

Marking gauge
http://www.youtube.com/watch?v=iKLsbCp7qc8&feature=autoshare

Small Craft Building: Week 1

So this is the first week of our small craft building project.We have set up our teams and the bench on which we are going to work out our dory before the semi-semester break.On Monday, we just kicked off.In this blog, following contents are included:
- Review of this week (our work on Monday, Tuesday and Wednesday)
- Looking forward to Week 2
- Team name

Review of this week

Monday

we started to do some adjustment of the bench in the morning. There were two major issues we have for the bench: the first is that the bench is not long enough. As Vaughn told us that the bench should be at least as the same length of the dory.Given consideration of the space we have in the workshop (Team A just next to us), we decided to extend our bench on both sides.

Extending the bench

Extending the bench

The second is about the level.As one side of the bench is slightly lower than the other side, we need to find a way to solve this.A level is used to check the bench.We also planed the bench.

Checking the level

After the setup of the bench, we used a string to mark the centerline. Just make sure that the string is tight enough and is straight from one end to another.

Marking centerline

Marking stations comes next.One thing needs to be noticed is that we should have 40mm at the forward for the thickness of the stem. So station 0 is actually marked 40mm behind the edge of the bench.

Marking stations

After finishing the bench, we started to work on temporary frames.But we made a error here. We did not cut the first board according to the plan. We just cut it into three parts with the same size. Then we realized that as the temporary frames are in different size, we might have problems on some of them.Luckily, after calculation and planning for the cutting, we found that we can still get all frames. The lesson is, before cutting, do the calculation and cut it according to the plan.

Next thing is to drawing the frame on the board as preparation for the cutting. This is similar to lofting.

Tian is drawing the frame

Tuesday

On Tuesday, our first task is to continue the frames.In order to cut the frame as accurate as enough. We first used the bandsaw, then used the sander. We also tried to sand the edge of frame to correct minor errors by hand. Just as Chris told us, keep the lines. If you can lost the line, then you lost the reference (but unfortunately,we found out that one or two frames lost their lines, and this error made them 1mm shorter than they should be) .After finish all of them, we need to set them up on the bench.But before we do this, 'ribs' are added to the bench on each station. Here comes one question: which side of the station should we put these 'ribs'? This is little bit confusion. We asked Vaughn for help and guess what, we got a perfect answer: you need to consider the curve of the hull.Because the frames are supposed to support the hull during the construction process, we need to bevel the frames' edge. So if you put the frames on the wrong side of the station, you can not make it. So, for statoin 0,1,2,3 (actually as station 3 is the midship station, it's frame side does not really matter), we put the frame in front of the station lines, for station 4,5,we put frames after the station lines.

Continue working on frames

Cutting frames on bandsaw

Sanding to make the frame accurate

Vaughn explaining frame positioning

Wednesday
Setting up frames on the bench is a challenging task. As the bench itself is not leveled , we need to use widget to level the frame. Use the level to check the level, then make the appropriate widget, and put the frame on the widget. This is the first step. Then,we must make sure that the center line of the frame is aligned with the center line of the boat (which is marked by a string on the bench).The third step is to drill the frame to the rib, and then using 'support arms' to hold the frame tight. Make sure the frame is perpendicular to the bench.

setting up the frame

Later in the day, in order to accelerate our progress,and also to work more efficiently, we decided to split our team in to two groups. Tian and Kenny work on setting up the frame, while Sebastien, Jade and I work on the cutting plan and the stem. But I need to do the cutting plan in AutoCAD before I join Sebastien and Jade.

Talking about the cutting plan, I think it is one of the highlights for Wednesday. We need 9 pieces of yellow cedar pattern to make the stem.But actually at the beginning we did not have necessary clues to cut the wood we have. At first, we just take some spare wood from Team A (as they are working on Chris' boat, Chris provided them additional wood for the stem, so actually they did not cut them from their yellow cedar) for stem. However, Chris came to us and stopped us using these woods. Then he showed us how to make the cutting plan for the yellow cedar: which means how to get the most from the wood you have. A good start would be lists of main parts and cut offs.  And he also suggested that AutoCAD is a good tool for cutting plan.

Discussing cutting plan

Hints for cutting plan

We cut off segment of the yellow cedar for the stem before we made the cutting plan, despite Chris told us to ask him before we start to cut.Luckily this does not cause much waste. Chris said that one of the yellow cedar may be enough for the whole boat. And my cutting plan shows that one is enough.Obviously Chris had the idea that students may make mistakes and they surely need more woods in his mind when he ordered those wood.(to add picture of our cutting plan)

We used the segment we already got for the stem (actually this was exactly what it was cut for). We need 8 batten with 5 mm thickness to make it 40 mm thick and another one for the out surface. Bandsaw is used for cutting. And then this 9 batten are put into the steam to make them soft. This took about 30 minutes.We also printed out full size (1:1) drawing for the stem and fix it on a board.

The stem

Looking Forward to Week 2
We will continue our work on the frame. There are some errors we need to fix for the frame. And we also need to bevel edges of frames according to the curvature of the hull. Have not got any clue on how to do this.

The second is to finish the stem, glue those 9 battens together.

The next thing is to finish the laminated midship section.

And finally we are going to cut yellow cedar following the cutting plan to start to make parts.

Team Name 
We decided to name our team Team Morris after the name of the owner of the dory, John Morris.