Paper and pencil

Ultimately, hand drawn plans have to be faired on the loft floor. You don't need to be particularly accurate with hand drawn stuff for this reason, the actual lines will be determined with a batten at full scale, during the initial stages of the build. This is quite different from a CAD derived drawing, where the accuracy can be calibrated down to a single thousandth. Neither process teaches you how to design, just how to draw.

Before you can use either drawing technique, you need to learn what is what, so the resulting lines are as well suited to your goals as practical. Learning the subtleties of these shapes and lines, what they can offer/detract from a particular set of goals is the hard part. Recently I was attempting to describe why a young part time employ of mine, with some design aspirations, would want to increase volume in the bow, on one of his hypothetical sailing yachts. He drew a nice, slightly hollow entry in the WL's, but kept this well up the bow. He thought it looked better, but I suggested it would sail better if he permitted volume to fatten and eventually convex these lines, to control bow dive and leeward wave train heights at displacement speeds. He was lost, not having much sailing experience, nor any real flow dynamics background. It's the study part of the equation that makes designing enjoyable. Learning why things are done the way they are, the negative and positive results of various decisions, etc. Software can fool a student into thinking, the finely faired drawing is a great boat, when in fact it hits the water as a pig, if built. The experienced eye sees these potential concerns, before materials get cut, the computer jock doesn't without a firm grasp on the fundamentals of design.

As to hand drawing, there's the same amount of information that needs to be absorbed as one that's track ball tweaked, though admittedly, the computer does take a great deal of tediousness out of the effort. For everyone that wants to learn hand drawing, they should first do a weight study from a existing GA, then a center of masses calculation. This will quickly teach them how badly they'll want to learn about CAD work. Either that or having to use an eraser shield on the entire back half of a set of lines, to redo a more appropriate set of buttocks, for a particular angle or Cp (or whatever), will teach the pen and ink guy pretty quickly.

 

Boatbuilding and repair experience also can make you modify a design. For example, slightly hollow lines on the bow make planking easier because there is less tension. It also makes the fasteners work less, which results in a longer lasting hull.

 

Is that actual or theoretical? Reason I'm wondering is because if it's actual, those Scandinavian double enders (spidsgatters, Nielsens, etc) should have short-lived sterns. As far as I know, they don't.

 

Have you ever planked one of those? It takes steaming, clamping, sweating, a lot of cussing, block and tackle, and there is still a fair amount of tension on the fasteners.

 

Oh I realise they'd be a total ******* to plank, but how do they last once you get the damned planks around the shape?

 

The recess is for drafting with an ink pen such as a Rotring or Faber Castell type. I've done a reasonable ammount of that with a pen and the totally flat sided curves allow ink to weep under the edge and that really is a PITA to clean up even on film!

 

For now, yes, I'm in a stage of sheet ply dinghies. You have to start somewhere, so starting small makes sense. Someday I hope to move on to larger projects, although I don't see 30m schooners in my studio anytime soon.

When I manage to get these splines, I'll experiment to see what can I use to hold them in place.

SukiSolo, is this the book on drafting standards you mentioned?

Yeah, and in our country, these drafting boards cost a lot. For example, 90x30cm costs around 30$. Used. And that is small. But I'll keep loking.

All right, you've beat me. I'm not as good in googling as I thought I was. Of course, this isn't expensive. Books cost more in our country even without shipping. I'll probably order this one.

All right, I'll buy then whenever I find decent ones.

I'll have to search. I know for sure there is nothing about boat design in our country, but maybe some neighbor countries.

A food for the thought, thank you.

 

The book I have is called 'Manual of British Standards in Engineering Drawing and Design' published by the BSI in association with Hutchinson. ISBN is 0-09-151911X at least for the paperback version. As the current standard BS8888 is only very slightly different and pretty easy to find any odd changes for via the web, this is still a good all round book. It was available for 1 dollar on one site plus shipping.

One reason I like it, is that it ties in loads of related standards that allow you to interpret or draw a lot of engineering things in formats for related disciplines. A hell of a lot cheaper than buying individual standards which are half the price in Switzerland compared to the UK. Effectively even this old book is incredibly close to current ISO standards. Please remember that this book is intended for commercial engineering drawing from many disciplines, do not expect a step by step tutorial. However it does give plenty of guidance as to how to represent things graphically and correctly. You will either love it or hate it - if you want a more basic pure tutorial perhaps another title may be more appropriate.

The book you pointed at is part of a series of more recent titles. Ideally you might try and find ones in a library so you can look at them to find what you want. You should find Universities and Technical Colleges have these in paper form not just online reference. BTW it is often much quicker to find what you need in a book rather than scrolling through long pdfs' at least in my experience!.

 

The tension on the fasteners for a plank with a slight hollow is divided between those on the bow stem and those on the last frame.

 

Funny you should say that..

https://www.youtube.com/watch?v=HepAG8ziOyk

Greyhound was designed and then built using the curves/planimeter etc I sold Chris

You should check out youtube, eg this channel

https://www.youtube.com/channel/UC0oIxkUHPkOxqM2QAcHqiog

Richard Woods

 

*waits for Laukejas to open a thread in Hydro about giant three-masted luggers*

ETA: That second channel looks very useful.

 

As far as cheap drafting goes, it depends on if you want to store the result for years. If yes, you need vellum and a drafting board of some sort. If no, you can take down your bedroom door, sand it, draft on it, build the thing, then paint the door and hang it back up.

Don't laugh, I did that for years. I live in an RV now and don't have a suitable door anymore, so I had to buy a drafting board. I also built a larger table that breaks down into flats. For lofting or patterning, I just buy a sheet of door skin, and paint it and work on that. It holds up better than paper if it is going to be outside for a month. And you can cut it up for patterns on the next project.

I paid $9 for my ship curves at the fabric/hobby/art/drafting shop around the corner.

I do have a pretty good collection of drafting junk now, but some is still from the basic kit I got either in high school or college. And somewhere, I still have a great old paragon drafting machine that is from the 1940's. Great for clamping to doors.

http://www.ebay.com/bhp/drafting-machine

They must have been selling this kit for 40 years now this is the one I started with.

http://www.artsupply.com/Architectural-Technical-Blueprint-Kit_p_66348.html

 

technology's benefits shouldn't be ignored

laukejas,
I'm not a musician, but I've designed and built hundreds of welded aluminum boats from 30" to 40' for the past several decades and want to remark about your quest to learn hand-drawn boat design.

I'm especially not a musically literate- but will attempt to use some musical metaphors to hope I'm improving my level of communications.

I do appreciate your remarks about wanting to learn to draw boats with paper and pencil, and having started that way would like to mention in terms not yet used a caution or two.

I don't know what instrument (make, model, year, type, or details) you use but would like to ask if you use machine made stings or hand made strings? This critical path feature of uniformity, whether of metal, plastic or organic materials seems important to consider?

I'll suppose that someone is out there making hand made organic 'gut' strings and some players of the guitar may find them the 'only' authentic sound? but I suspect there are some (99.8%) of the market that relies on machine made strings.

Next does the luthier who made you concert instrument work with any machine made tools or are all his/her/their tools made of wood and bone and rocks? I suspect there are no instrument makers who still rely on the inexact, not fully uniform or the 'best' tools they can find? WHy is that?

The reason is to bring about the best fitted, most well designed and made instrument to bring out the best sound (I have worked in industrial settings for so long I can't even hear 1/4 or normally perceived range of frequencies) 'possible'.

So I'm countering any luddite, "trash the computer tools"; do it all by hand thinking with the example from within your own field(s) and asking that the improvements in machined strings instead of irregular gut strings metaphor be seen for your own education.

By hand, you will have to build a model to see the foreshortened lines of the hull. One cannot use the three (classic drafting) views to see foreshortened lines and they, among all views, are one of the MOST artistic and aesthetic considerations of small hull design. No where is the example more critical than the sheer and chine of skiffs, or any small boat.

But in almost all 3D marine modeling program you can instantly rotate in all views the entire sphere of visualization around your design and make refinements that cannot be done without full and whole hull modeling using a traditional drafting methods.

So, just as there is one critical and essential machine made wire string attribute, which is consistency; therefore reliable, repeatable and consistent "tune-ability" making all music possible on that set uniform section strings: so too, digital modeling provides an element of visual design refinement that will take dozens (if not hundreds) of hours of labor/effort/expenditure to even 'check'.

So you draw lines set, create the plate model, and take off the panels, then plate/plank the model. Now, how many hours is this? dozens if not more. What do you get, views of what the computer will give you in less than a second.

So, I do understand your interest in learning to design using paper and pencil, I caution you that you may be attempting to ignore machine made strings and ask you:

how much time would you spend tuning during any performance if your strings were make up of lumpy, irregular gutt hand made and without the benefit of machining?

Well that is the same amount of time you will spend, using pure graphite on vellum and making dozens if not plural dozens of models to find fair foreshortened lines of small boats.

You've mentioned the tuning exercise is a non-trivial skill;(I'll defer to your experience, expertise and enthusiasm) I assure you refining the lines in the 3D as they relate there (not in classic views) is also a non-trivial exercise. And you're setting yourself up to redraw how many times? not to mention how many models? just to view a model in the non-traditional views?

I'd suggest you combine the software and (digital) hardware, with the hand drawn which is easily done in today's world, and enjoy the enhancements of all the tools available to draw a finely tuned boat, before your cruise reaches harbor!

Cheers,
Kevin Morin
Kenai, AK

 

I don't think the analogy holds. Designers that only know how to use computers will have to design a boat, make files for CNC, send them to be cut, etc. before even beginning to build. On a smaller boat, I would probably be painting by the time they are done. Yes, I have timed myself. Small dinghies can be finished in five hours or so. 12' sailing skiffs, including the mast, in about 20 hours.

 

analogies applying to circumstance

gonzo,

Do I take if from your post you're just learning? this is your first or second dinghy- right? I mean to apply your experience that you can do this in some time frame is sort of meaningless unless you're equating yourself to the OP?

I can design and build welded boats pretty quick compared to someone who's not done it too... so what does my plural thousands of hours of welding boats have to do with someone who doesn't even know how to hook up the power supply?

come on! If the OP's conditions are considered; of course he's not done enough work to make a project in short time. You may or may not need to view the model or a 3D view -before completing the design but a 2nd or 3rd skiff novice? That stretches my credulity to breaking.

let's get real, that first couple dozen boats is a real milestone and unless our OP has passed that point- he's not finalizing his drawings PC OR Pencil in 5 hours!

IT will take more than that time just to do his first couple of displacements/CB/CG by hand!

My point was that the OP should consider the best tools for each job. The analogy of using poorly made (guitar) strings is still pretty valid in my view, OP's just getting started so handicapping himself with some unneeded limits seems foolish to me. It has little to do with the experienced who have this learning time under their belts.

I freehand on the WACOM 18, output with spline fairing of freehand then scale to a background layer in hull modelers (Rhino/D'ship); develop surfaces and output outlines as vectors and re-spline outlines in AutoCAD- (confirm they will input to G code without error). Test for shape of panels in stock size plates.

This prelim gives 'buildable' in stock size boats or; Go back with refined outline info on flam, deadrise, chine flats, panel sizes and return to the loop, mod the hull sheer or chine as implied by stock plate outline test and fine the shape to fit. Redo until the hull shape as drawn can be built with min hull seam then re-run balance.

At almost all edits- do the Hydro calcs and confirm LCB/CG and in last few iterations assign material mass to make the VCG and VCB & Km realistic for the proposed hull's material wt. Create the artificial objects of the engine, fuel and hardware and assign wt/mass, re-calc all V and L CG & compare to V and L CB and move items to level if needed....

I'm looking at a 27" monitor 2500x1600 screen using the Nvidia Quadro Pro 16G video card in a 32G 16-core (four quads) processor mother board... and don't have much pixelation to conflict my view....

That's a couple hours or so...
Gonzo.... do I think the OP can even understand what I do or expect him to even understand the spec for the display?

nope. He's not "been there and done" that according to his posts.

Do you think he'd understand your work flow?

nope.

He's learning to learn the marine design process. I think that's the level of his understanding? ON the other hand I bet if we quizzed him on the some guitar piece technique for his "vibrato on the E string"; neither of us would know what was being discussed either?

I'd be learning that's for sure.

Cheers,
Kevin Morin
Kenai, AK