Plan Redrawing Question

[Castos]

Good Day All

 

Hope everyone is putting the lockdown to good use by building.

 

My question when redrawing plans (sketch included). it goes about lineweights and do I draw the line to cover the complete lines on the plans.

 

Thanks in advance for the assistance.

Lineweight redrawing.pptx

[iMustBeCrazy]

45 minutes ago, Castos said:

My question when redrawing plans (sketch included). it goes about lineweights and do I draw the line to cover the complete lines on the plans.

I would say "it depends".

 

If you are trying to duplicate the original then duplicate the original line weights.

 

If you are trying to create a pretty picture then use the line weight that you think looks best.

 

If you are trying to produce a plan to use as templates then choose a narrower line that is still dark enough when printed.

 

But don't get hung up on line weights at the moment, it's better to get them in the right place first, you can change them later. See my Lapwing thread, I'm using all colours and weights so I can more easily see and differentiate the lines. Drawing a thin black line over a thicker black line makes it hard to see what you've done. As I finalise them I'll reduce the number of colours and line weights to suit a nice print.

[Matrim]

I used the default of the thinest line possible. When drawing the line you can drill in to such a large amount that you place that line what wouod appear to be the middle of the drawn line and that goes a slight way to coping with the vagaries of warped paper and sometimes moving lines.

 

Tying to match plan widths with specified widths may cause difficulties with sizing and printing with some CAD systems as well.

[Castos]

Thanks for all the replies

 

I am going with Matrim's advice. Have progress quite a bit whilst on nightshift, with the redrawing of the lines. I now also understand Matrim's statement on warped paper, as I see it on the plans.

 

Will start a topic shortly, so that I can get advice on where I am making mistakes and how certain things should be done. I am also making use of the write up EdT did in his book on drawing of plans,  Thank you EdT, as well as the good people on this forum.

 

Regards

 

Andre 

[Matrim]

Ed's article is excellent (and I used it myself). I do cover a few gotchas in my own plan build topic so it may not even be relevant..

 

 

[Castos]

Thanks for the assistance.

 

What I have done so far is to read some of the blogs where redrawing of plans was done. I then started with redrawing a plan. At this stage I am still learning all about tracing - have erased and redrawn numerous times until I get it perfect and this is where a CAD program is handy. Imagine doing all this by hand. This is still a learning curve for me, which I will master.

 

Once I have advanced to a higher level of tracing accurately I will start a blog, showing what I am doing and how I did it. Hopefully I will get advice from the members where I have done wrong and what I should be doing.

 

Regards

 

Andre

[iMustBeCrazy]

51 minutes ago, Castos said:

What I have done so far is to read some of the blogs where redrawing of plans was done. I then started with redrawing a plan. At this stage I am still learning all about tracing - have erased and redrawn numerous times until I get it perfect and this is where a CAD program is handy. Imagine doing all this by hand. This is still a learning curve for me, which I will master.

I'm still redrawing things, this will continue long past the learning curve. This will be a long job.

 

53 minutes ago, Castos said:

Once I have advanced to a higher level of tracing accurately I will start a blog, showing what I am doing and how I did it. Hopefully I will get advice from the members where I have done wrong and what I should be doing.

The sooner others point out errors the less you have to redo. Everything is inter-related, moving one point may mean moving many others.

 

Also when you're happy with something, lock it from editing. You can always unlock it later.

[Castos]

Good Day

 

Thanks for all the advice. I have been practicing my skills at redrawing and the more you do it the better it becomes. I will continue (drawing, deleting all the lines and then start all over again) like this until I am happy and that the lines, curves joints are fluid. I have included a photo. I am in South Sudan since the February and with the lockdown - time period unknown so I may as well use the time on hand to improve my capabilities and learn from all the Masters on this site.

 

While researching I came the book on Spanish Shipbuilding La Arquitectura Naval Española, which provides a lot of info (in Spanish) and sketches.

 

Regards

 

Andre

 

 

[Castos]

Good day

 

Still redrawing and doing research on Spanish Shipbuilding and came across a lot of data for dimensions. If looking at the papers and documents I have researched, it seems to me that there was a lot of designs from Portugal (mainly) and then French and English influence. 

I also found out that the architect for the Santisima Trinidad was an Irishman. Now this makes one wonder if the ST was built according to the Spanish or English styles or a mixture of both. More research has to be done and thanks to the virus for the lockdown which has provided me with the opportunity to do this - lots of time on hand. 

 

Stay safe and happy building.

 

Andre

[druxey]

Well, the Swedish employed Frederick Chapman, son of a British naval officer, so I'm sure that there was a fair bit of trading of ideas and personnel between nations in terms of design. I'm sure that, as an Irishman, that gentleman was more than happy to design against the British!

[JohnMGray]

If you haven't already seen it, download "Drafting Ship Plans in CAD" by Wayne Kempson, from "http://modelshipworldforum.com/ship-model-plans-and-research.php". As far as warped plans go if they are really bad you can make a template overlay using baselines, waterlines, centerlines, station lines, etc. Then use the overlay set to translucent to unwarp the plans in any decent photo editor (e.g. Photoshop).

[JohnMGray]

One drafting trick I learned from school (in the 70s on paper and vellum) was as follows.  If I draw a horizontal line from the intersection of station 38 and waterline 4'6" on the shear plan (point A) to the same intersection on the body plan (point B), then draw a vertical perpendicular line from the body plan (point B ) to the intersection of a 45 degree line from the centerlines of the body and half breadth plans (point C), then a horizontal line from point C to station 38 of the half breadth plan (point D), it should intersect with the waterline 4'6" on the half breadth plan, which will be the same as back at point A. All lines are 90 degrees from each other. This holds true for every intersection on the plans. So if the shear and half breadth plans are good then you can easily recreate the body plan stations, or create the half breadth plan from the shear and body plans. If the 3 plans don't line up as shown below then just digitally cut them apart and make them line up.

 

 

Edited May 10, 2020 by JohnMGray

[Castos]

Thanks John for the assistance, will do so.

 

At present I am redrawing to improve my skills at using ACAD. At present I have am experiencing to problems, viz., Joining of lines to ensure a smooth continuation and when drawing curved waterlines, as I draw them in sections. I do not know if this is the right way.

 

I am using "Drafting Ship Plans in CAD" by Wayne Kempson and Russell Barnes's Interpreting Line Drawings. I have numerous books and research papers, that I bought over the years,  amongst others Deane's Doctrine (see below picture) to use, but I we all have the best encyclopedia in the world - all the modelship builders on this forum, who have a wealth of knowledge and are always assisting and providing information. Thank you to all of you.

 

Now to continue reading and practicing line drawing.

[JohnMGray]

I use Rhino for boat/ship design, and Solidworks for parametric CAD so I'm not too familiar with AutoCAD. The link I previously showed has some ACAD tutorials on it.

 

Regardless, you want to use a NURBS curve, or whatever ACAD has for an equivalent. Then you draw a single curve (with multiple bends) through the whole station (top to keel) (or along a curved waterline or diagonal) using control points, and then use the point handles to bend the curve to fair it for a better fit. You can do this two ways. Use my above method to get all of the waterline/station intersection points for a single station (or waterline or diagonal), then connect the points with the curve. Or, freehand the curve by clicking at points logically located along the station line (or waterline or diagonal) such as as maximum/minimum concave/convex points. Don't make a single station line consist of multiple sections/curves. It should be one curve/line with multiple control points. Also, I find that too many points is more of a problem than not enough, although you can add or remove points easily.  Once you've done a couple of them you'll see what's best.

 

I should also mention that the only time I use multiple segments is if drafting the plans from scratch. Then you draw the arcs in accordance with standard methods, overlapping the ends, and delete the excess parts beyond where the arcs intersect. But you'll still find yourself combining the segments and using control point handles to fair them.

 

Deane's book is a good one. I have my copy in front of me right now for research I've been doing. Steel's "Shipwright's Vade-Mecum" is also good. If you don't have a copy of the folios, or access to them, you can order digital copies of them from the Bodleian Library at Oxford University.

Edited May 11, 2020 by JohnMGray