New curves!

[Nicholas Carey]

Crucible Tools, Christopher Schwartz's offshoot of his Lost Art Press, is introducing a new tool: a set of curves.

https://blog.lostartpress.com/2017/0...design-curves/



Not a full set of ship curves, but still nice.

[Tom Lathrop]

They are French curves and would be useful for a designer of boats. I like my plastic ones better though for a couple reasons. You can see through the to align the new line with some existing ones. Marks on the curve for registration of line segments can be easily wiped off. I like the ability to tilt a pencil to help in joining line segments when no part of the tool quite fits. I suspect a pencil will glide along the plastic easier than on the plywood edge. Like many other old school pencil & paper draftsmen, I sometimes make plywood French curves for special uses.

The main objection to standard curves is that the range of options in making inflection point transitions of line segments is very limited. Very large radius curves are also limited in standard tools. Some more like these would be useful. Just a personal opinion.

[Jay Greer]

LFH had a set of oval, egg shaped, curves that had belonged to his father Nataniel. I understand that they were very handy for drawing hull sections. Unfortunatly, I failed to ask him who made them before he passed on. So, I continue to limp along with the French curves I have used for many decades!
Jay

[Gold Rock]

I'm interested in that they are made from a 5 ply laminate of bamboo. Intriguing...

[Bob Cleek]

LFH had a set of oval, egg shaped, curves that had belonged to his father Nataniel. I understand that they were very handy for drawing hull sections. Unfortunatly, I failed to ask him who made them before he passed on. So, I continue to limp along with the French curves I have used for many decades!
Jay

The oval-shaped, "nesting," set you describe was designed by Dixon Kemp and are highly regarded. They are illustrated in his book on yacht designing. At this time, I know of no one who's making them. It might be a good sideline business for somebody with a laser cutting rig to knock out a few sets.

[Bob Cleek]

Well, while I applaud anybody's producing near-unobtainable drafting curves these days, I am surprised that these manufacturers would go to the lengths they have to justify making theirs out of laminated bamboo. Perhaps it was less expensive than high-quality plastic sheet or their laser cutting equipment couldn't handle plastics or metal, I don't know. Having read their site, though, I disagree with several assertions they've made.

They are only offering three French curves of relatively small size. These are of very limited use in naval architecture. Wooden curves are subject to nicks and dents on the edges which render those edges useless. The only advantage to wooden curves is that they can be shaped by the user with sandpaper or a plane (except that this may be difficult with plywood edges rather than the solid wood edges of the antique wooden curves which had to be "touched up" when nicked or dented.)

It appears their curves are as much as a quarter of an inch thick. While this might be suitable for rough layout work on the work-piece, it won't be anywhere near as suitable as the very thin 1/8 or 1/16" thick special plastic (e.g. "Xynolite") curves formerly produced by the drafting instrument companies such as Keuffel and Esser and Dietzgen.

Their comment that their curves are better because one can't write on plastic curves makes no sense. No competent draftsman would write on a curve in any event. A piece of masking tape on the face of the curve is used for marking "ticks" on a curve or rule. It can be easily removed when no longer needed. Similarly, the "beveled edges" on plastic curves which these manufacturers decry are necessary to prevent ink from running between the paper and the lower face of the curve and causing huge blots that ruin a drawing. These beveled edges are only found on cheaper curves in any event. The best curves don't have them so that if pencil is used, as these manufacturers note, an accurate curve can be drawn without the point running inward and leaving an unfair line. If ink is used on the finest quality curves, one places spacers, such as pennies taped to the bottom face of the curve, to raise it so as to prevent ink from running beneath it.

Their product is also rather expensive at around $10.00 a curve. A set of six ship's curves can be had from Alvin on Amazon for around $25.00. https://www.amazon.com/Alvin-Ship-Cu...rafting+curves A full set of Keuffel and Esser professional quality ship's curves, numbering 56, if memory serves, if one is lucky enough to find one, can be had in a fitted case, starting at around $250 on eBay.







The wooden ones pictured in the post would be handy to have in any shop, but they won't do much good for drawing boats because they are French curves, not Copenhagen ship's curves, which are shaped differently and provide "sweeps" that are much larger, in the range of 18 to 24".

[amish rob]

I glue little cork "feet" under my curves, like on the back of my ruler.

I don't have any ship curves, though, just some French guys.

Peace,
Robert

[Tom Lathrop]

My curves are not beveled either and I've used small bits to hold them off. Now I seldom draw with ink and use thin marker pens that don't bleed. Don't have any ship curves but do have several plastic templates intended for highway layouts that have large radius arcs. Flexible lead center curves get used a lot as well.

[Jay Greer]

The oval-shaped, "nesting," set you describe was designed by Dixon Kemp and are highly regarded. They are illustrated in his book on yacht designing. At this time, I know of no one who's making them. It might be a good sideline business for somebody with a laser cutting rig to knock out a few sets.

By golly Bob, I appreciate your comment on Kemp having them listed. It has been so many years since I opened my copy of Kemp I had forgotten. I will check today.
Jay

[Jay Greer]

I did check both my copies of Dixon Kemp and no curves are shown in them.
Jay

[Bob Cleek]

I did check both my copies of Dixon Kemp and no curves are shown in them.
Jay

There is a picture of Dixon Kemp's "pear-shaped curves" in his book, Practical Boatbuilding for Amateurs, Chapter 1. Designing, Figure 1. A drawing of them can be found at: https://books.google.com/books?id=n8...20Kemp&f=false (I can't lift the drawing from the book I found on line.) The book is available in a paperback reprint: https://www.amazon.com/Practical-Bui.../dp/1929516134

The original Dixon Kemp "pear-shaped curves" were manufactured under Kemp's license by W.F.Stanley, London, a well-known English drafting instrument company. They came in two sizes, a large set and a small one. The largest curve had outside maximum measurements of 12"x7" and the smallest curve had maximum outside measurements of 3.5"x1.5". I don't know if these dimensions are for the larger or the smaller of the two sized, but, given the size of the smallest curve in the set, I presume the dimensions I found were for the smaller set. The larger would then be proportionately larger. One could do the math to suit their own taste.

[Jay Greer]

Bob,
That Dixon Kemp book is one that I do not own. I have the two volume treatis on navel architecture printed in 1897. So, I thank you and will see if I can pick up the one you describe. Thanks,
Jay

[Peerie Maa]

Flexible lead center curves get used a lot as well.

I don't like those, as the lead core can take a set which is hard/impossible to remove.
These are much better for longer sweeps


And a set of decent French curves for the tight turns.