It is a code, procedure that you must follow for efficiency and accuracy, I think.(to avoid an error, wasting time and not to screw, proven method for years and generations)-->Correct me if you have a more proper explanation. Lofting Schedule could be true of any lofting work cause it's universal work procedure for lofting.
It is a proven procedure by which means it's in order, so follow steps below.
1.Measures
You will need various measures for drawing and if you do it altogether before you start drawing on a cardboard, it would be much more efficient.
Since I didn't know what kind of measure I need, I had to go back to CAD LAB everytime I need new measures.(Actually Wei dit it with us.)
① Table of Offset
Table of Offset contains heights of each curved line at each station in Profile and Beam(width) of each curved line at each station in Half Breadth.
- Height is a distance between curved line and LWL(Load Water Line) in Profile and can be negative value.
- Beam(width) is a distance between curved line and CL(Center Line) in Half Breadth and can't be negative.
- Horizontal(Longitudinal) straight lines(Buttock lines) in Half Breadth become curved line in Profile.
- Horizontal(Longitudinal) straight lines(LWL, WL -60 / 100/ 200) in Profile become curved line in Half Breadth.
- Table below is a table of offset for the dinghy we're drawing.
② Stem Face Details in Profile
Table of offset contains various sets of informations on the lines, but it doesn't have enough informations on some lines including stem face. Stem is an extended part of keel at bow.
As shown in the table of offset above, Canoe Body has no measure in FP and even though it has the value, it's more likely straight line between Station0 and FP with measures provided. But it is not. So this is why we need Stem Face details to compensate.
Before we had three values for stem faces at station 0.5, 0 and FP but now we have four more measures WL-60, LWL, WL100 and WL200 for stem face. And I think this will do.
③ Buttock Kinky Point in Profile.
All the bouttock lines have fair line and kinky line altogether in its line. It is important to know that some part(line at bow) of the line is kinky. Just because I didn't know this, I spent more than half an hour to draw fair line which is not fair. So we also need those measure of each kinky point in each line.
Buttock 400 has kinky point at Bow and Stern but Buttock 200 & 50 have kinky point only at Bow.
④ LWL Kinky Point in Half Breadth
Like Buttock, LWL also has kinky point at its stern and we need measures for those kinky points.
Now, I guess I am all done with all the measures for lofting. Next is to draw real lines on cardboard.
2.Drawing on cardboard
Until now, all I did was a just preparation for lofting and not it' time to hit the board! REAL lofting.
One thing to note is that there is a priority or sequence in drawing lines which means if you don't have a certain line before you draw a specific line, then you can't. But if you have it already, then you can.
Since I have Lines Plan for blog posting topic and Lofting Schedule means sequence, simply I will describe drawing sequence below and write a post on Lines Plan for more details.
① Grid Line
② Sheer Line(Profile) and Deck Line(Half Breadth)
③ Chine in Profile
④ Canoe Body and Stem Face in Profile
Note. It is important that you keep the sequence above.
- By drawing Chine in Profile, you have the intersect between Chine and Canoe body in Profile and this intersect is start point of Chine in Half Breadth. And thus, now you can draw Chine in Half Breadth.
- Since you drew Canoe Body in Profile, you have intersects between Canoe Body and four Water Lines(LWL, WL-60, WL100, WL200). And these intersects are the start point of four Water LInes in Half Breadth. So now you can draw those Water Lines in Half Breadth.
- By drawing Deck Line in Half Breadth, you have intersects between Deck Line and three Buttock Lines(Buttock 50, 200, 400). And these intersects are the start point of three Buttock Lines in Profile.
So now you can draw all the lines left which are Chine(in HB), Buttock Lines(in Profile) and Water Lines(in HB). And there's no sequential order for those line left. Draw whatever line you want to draw.
⑤ Three Buttock Lines in Profile - 50 / 200 / 400
Check whether ther are kinked points on the lines, and if there's any, you should have done checking details when you were doing Table of Offset.
⑥ Four Water Lines in Half Breadth - 200 / 100 / LWL / -60
Check whether ther are kinked points on the lines, and if there's any, you should have done checking details when you were doing Table of Offset.
Now we are all done with all the lines in Profile and Half Breadth.
⑦ Body Plan
By using Tick Stick, you gather all the information from Profile and Half Breadth and transfer it to Body Plan. You could find detailed information on this in Lines Plan(not at this moment,,I am still woring on it) posting.
⑧ Stem Sections
Top view of half section of Stem at some different position, details in Lines Plan post.
⑨ Transom(Angled, Thickness) and Transom Section
- Draw transom line in Profile with 10 degree and draw grid lines on new cardboard attached.
- By using Tick Stick, gather information of intersects between Transom Line and all the lines in Profile.
- Transfer gathered information to Half Breadthe and draw new line in Half Breadth.
- By using Tick Stick, gather information from the new line drawn just before in Half Breadth(distance from AP to the intersects of all those lines in Half Breadth), then transfer it to new cardboard for transom.
More details are in Lines Plan
⑩ Joint: Stem Face and Hog
⑪ Calculation
- Simpson's one third rule.
- Area Calculation
Guess now I am done with Lofting Schedule.
Once again, Lofting Schedule is the sequential order that you have to follow for efficiency. All you have to do is, get used to do it in right sequence, sort of "Body Memory".
And more details on each sequence will be in Lines Plan which I am still workin on.
Cheers,
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