Making a Scroll Jig

[RustyLaidlaw]

As many of you may know, I'm in the process of making a sign bracket for an art gallery in Lunenburg. A big part of that sign bracket is a number of scrolls. The real question, at least to me, is "How do you make a scroll?". I've tried many, many scrolls free-hand and out of maybe a million (at least it seemed like that many) maybe one turned out just right. How did the old timers get their scrolls just right? I mean people in the 15th century were basically uneducated idiots compared to us, right? So how did they make those fancy scrolls and complicated iron work?



Simple. They used mathematics. The Greeks were the first recorded people to catch on to this insanely simple concept - that nature creates pleasing shapes, so why shouldn't we? From the nautilus shell to the distance from your armpit to your crotch, nature plays the same pattern over and over again. Today we call it the "Fibonacci Ratio" or as the ancients coined the term "The Golden Mean".



I hear you asking "Okay...so some old Greek dude came up with some *stuff*, and that relates to metalworking how?". I'll tell you how, and it's as creepy as alien abductions. Cause steel at forging temperature actually forms with even hammer blows into the golden mean spiral. I know, intense right? The only thing a blacksmith has to do is take the shape of a nautilus shell and make a replica in iron. Everything else follows like clockwork. But how?



First, you have to understand the Fibonacci sequence. In the "golden ratio" the simplest way to envision it is a line divided in two, but instead of a ratio of 1:2, it's more like 1:craziness. So 1/2 is 1 divided equally into two parts, where as the Fibonacci sequence is exactly 1+root 5 divided by 2 which equals 1.6180339887. But, you might ask, how does that make a scroll? Simply. The mathematics of the golden ratio and of the Fibonacci sequence are intimately interconnected. The sequence after all the maths is as follows: 1,1,2,3,5,8,13,21,34...etc. So to find the golden spiral we do the simplest maths possible, use the first 6 numbers to draw a rectangle, and from that rectangle work down the sequence to form all squares to fill up the rectangle, and from there, draw arcs from the corners of each square till they touch and make a spiral. Easy right? It'll look something like this:



Now, to make my steel look as immaculate as that. First, I need a hardy bending fork (the thing stuck in my anvil) a scroll bender (the same thing but with a handle) and a piece of steel (Ta-daa!)



First I take my steel, in this case a piece of 1/4x1x36 inches long and forge a pretty (I'd even say gorgeous) fishtail at the end, with a beautiful (I'd say immaculate) taper to the end. Such as this:



Next we take that beautiful taper and offset the #$%@ing thing we worked so hard to make pretty, like so:



Offset

Now we take a pause to see if the fire is hot enough to heat a good section to start our scroll. To check this we use a complicated pyrometer known as "Little Iron Man". By the looks of things based on his facial expression, it's #$%@ing hot in there:



Looks perfect to me, let's proceed


Next step is to start the scroll over the edge of the anvil. It has to match the diagram. Like so



As evidenced by this tell-tale burn mark...



So basically we just tweak and twist with the bending forks till we end up with the final shape. Weld that to a hardie shank, and set it into the anvil, ready to shape new scrolls to the golden mean! As per:



And...



From here, I can forge a good long taper and bend a scroll to fit the golden mean! Which by the way, is the most pleasing shape known to nature And by nature I mean everyone

By the way, here's my fork when it's not in the hardy hole:

Edited March 2, 2011 by Moderator54
language

[Marksnagel]

Rusty, thanks for explaining the mathematics of scroll making. It looks like it works very well, unfortunately english was my worst subject and 9th grade was the hardest four years of my life.

Really, thanks, it helps. I'll take any and all knowledge I can get. Pictures helped too.

Mark<><

p.s. 1st sentence, 3rd para. Mind the language.

[Larry H]

Man,...you are funny ...I like your style.

[Bob S]

p.s. 1st sentence, 3rd para. Mind the language.

oh please...

Bob

[RustyLaidlaw]

Sorry Mark, and anyone else who might be insulted. Sometimes I get a little carried away.
No offense meant
Apologetically Yours
- Rusty

[Marksnagel]

Guys, I'm not insulted. In my younger days I cussed like a sailor. Oh wait, I was a sailor.

Since this is a family friendly site and there are people of all ages and all walks of life, it is up to the more mature members to set the standards of conduct. This was a minor word that was used but can you go into a restaurant and use it? Is it socially acceptable? Well maybe now a days it is. Thats sad.

Sorry, but I think that inorder to maintain standards we all have to maintain acceptable language.

Mark<><

[Guest 569ec1a27ea4c874823ed052defdc5bc]

Rusty, thanks for explaining the mathematics of scroll making. It looks like it works very well, unfortunately english was my worst subject and 9th grade was the hardest four years of my life.

Really, thanks, it helps. I'll take any and all knowledge I can get. Pictures helped too.

Mark<><

p.s. 1st sentence, 3rd para. Mind the language.

Post was edited.
As this is a family forum, and the site is viewed by all demographics, the administration of this forum takes inappropriate language very seriously!

[eric sprado]

Rusty: What does 1+root 5 MEAN???Do you mean square root of five?? I'm excited to learn this but maybe a clearer explanation might be in order for this dummy.
Been wondering about this stuff for a while. I bought some circular graph paper from a surveyors supply here but my efforts don't duplicate nature like your formula(cleared up) does.. Thank you SO much, Eric Sprado

[RustyLaidlaw]

Yes, Eric, I mean square root of five. What it all relates to is that if you look at my drawing the largest square is 40x40. Units being squares on graph paper. Using the equation Fn=Fn-1+Fn-2 with seed values F0=0 and F1=1, we get a sequence of 0,1,1,2,3,5,8,13,21,34,55,etc. If we plot this out on paper, it forms a natural spiral. Like nautilus shell, or a pinecone, or the spiral sunflower seeds grow in. So. I have a 40x40 (8) square. From there, I make a rectangle that's 25 (5) x40. From there make a square that's 15 (3) x25. Then make a square that's 10 (2), and two squares that are 5x5 or (1). It's all in the sequence, as long as you use factors of that sequence. By changing the size/ magnification of the squares, you can control the size of the scrolls.

Clear as mud?

[ironsmith]

I have also been fascinated by the golden ratio, there is also a gauge you can make to create spirals as well,
here is the link to it fibbonacci there is a pdf there that you can use as a pattern to make it ...
also check out the tool song lateralus, it has a lot of fibbonacci in it as well , the song is based on it :blink:

[Frank Turley]

A couple of items. The scroll tool can be made of mild steel, but should be thicker and wider than the scroll to be wrapped around it. After offsetting the fishtail, the end of it is cut at right angles to the stock length. When you start the bend, if you're right handed the offset is facing left. If left handed, it faces right.

It is difficult to free hand a scroll to look like another scroll, even if based on the 'golden rectangle.' Archimedes had another way to lay out a scroll, and on paper, it looks kind of like War Room coordinates...concentric circles and criss-crossed lines. We should realize, however, that neither the golden spiral nor Archimedes spiral is like a chambered nautilis or a snail shell. They have different ratios. Some are tightly scrolled with less negative space between convolutions. Some are "loose." Yet both are legitimate scrolls. A good designer can make a quite open scroll using the proper sized steel, and the negative can dominate the positive.

One can make scrolls all day long on paper, but then what? To make it of steel, you must know how to free hand it. If you transfer the paper scroll to a steel plate or table, you can attempt to match your tool or scroll to the layout. I suggest that this is a pain, that it is time consuming, and that it will be a "back and forth dance" of bending and unbending. Drive ya' crazy. It is easier to make a scroll form to your liking without using a pattern. Make the tool a little oversized, so that you can make a soapstone mark on top of the tool to show you where to stop bending. In that way, the finished scroll will fit your designed module.

The catch is to forge and watch the negative space grow in an exponential fashion. Arithmetic was not my long suit in school, so I'll try not to get lost explaining "exponential." Another way to say it might be, there is a constant rate of growth from the center, and it may be more easily seen in the negative space that the positive. If the negative looks good, then the positive should look good.

One way to check the scroll is to draw radiating lines from the center outward, and between convolutions. As you get away from center, each line gets a little larger. If the lines stay the same length, you're no longer "growing." If the lines are getting smaller, whoa! You can drop back to see where you've started to go bad, and you can open it a bit from that point and rebend if necessary.

How can it be done, If you're not using math and geometry? By practice, and by realizing that you're involved in art and craft, not just math and science.

There is another type of scroll that we see in early ironwork. Once you get a little ways from the start in the center, the negative space distance between convolutions remains the same. The negative space does not expand. On this scroll, you will use more stock than on Mother Nature's style of an expanding scroll. Is this Archimedes spiral? Perhaps.

Another scroll which I personally like, is an oval or elliptical scroll. These were used in old time ironwork. They are a little tricky to forge, if you are used to forging with circularity.

Another consideration. Let's nit pick. You want the outside of the bend to be "flat," a bent plane surface, because of the way the tool is used. But when you bend flat stock, it concaves on the outside of the bend, and the corners stay high. I'm talking about cross-section, and this is a concomitant of forging. My old horseshoeing teacher used to yell at us, "It draws on the outside of the bend, and it upsets on the inside of the bend!" This can be overcome by using common sense forging. If you draw the hot stock lengthwise through a bottom swage in conjunction with a top fuller, you can forge a mild concavo-convex cross-section BEFORE BENDING THE SCROLL JIG. When bending, have the convex side up and it will become the flat side upward instead of concaving.

When you make the finished scroll on the scroll form, it should have a little of the concavo-convex, because it is a nice aesthetic.


"Practice doesn't make perfect. Perfect practice makes perfect."

http://www.turleyforge.com Granddaddy of Blacksmith Schools

[Glenn]

Many times if you do a search you can find all manner of information.
There are at least 10 Blueprints dealing with scrolls and related things.


BP0026 Principles of Design - Phi, The Golden Rectangle, and Figonacci

BP0022 Scroll Generator
BP0023 Scroll Design
BP0024 Scroll Design

BP0025 Scroll Design
BP0027 Scroll Design
BP0028 Scroll Jigs

BP0029 Scroll Design
BP0030 Scroll Design
BP0031 Scroll Design

[Pat Roy]

Glenn, thanks for the links.

Rusty; "From here, I can forge a good long taper and bend a scroll to fit the golden mean! Which by the way, is the most pleasing shape known to nature And by nature I mean everyone"

I disagree, don't speak for everyone.

[fciron]

Rusty,

Thanks for the clear explanation of the Fibonacci scroll.

Frank,

Thanks for posting an explanation of other scrolls. I too find Archimedes spiral to be a much more practical starting point for explaining scrolls to blacksmiths. http://en.wikipedia.org/wiki/Archimedean_spiral

As you said, a scroll is any curve with an constantly increasing distance from the center. A survey of old ironwork will show a lot more of Archimede's spirals than Fibonacci's. The Fibonacci method is certainly the most famous, it seems to be popping up in popular media lately, but I don't think it's the best for most blacksmithing applications. The scroll is used in wrought iron to fill space, so the curve of the scroll needs to be the one that fits the space. Some scrolls are narrow, some are fat, some are even oval!

I practice by sketching scrolls so I can see how to fit them pleasingly into different shapes. If I can draw a pleasing scroll then it's a lot easier to forge one. Watching the negative space is the key in both cases, because it is the space not the line where the math is happening, even if you don't do the math. ;)

[Jacques]

Found this

[ThomasPowers]

Actually people in the 15th century were basically HIGHLY educated folks compared to us, their education was just how to live and prosper in the 15th century---something i wouldn't bet a "modern" guy could do very well at all!

[John B]

15th Century, Columbus drifted into a very large island about that time didn't he?

Someone had to introduce ironwork to that side of the pond, so I guess it must be partly down to him you have such a rich history in forged ironwork over there, if only he'd turned left instead of carrying straight on. Ah well!

[ThomasPowers]

Now John; the vikings were smelting iron from ore on this side of the pond about 500 years before Columbus's Caribbean cruise...

Or as Oscar Wilde once put it "America had often been discovered before Columbus, but it had always been hushed up".

[Steve McCarthy]

Found this

Now I understand. ;)

[Iron Clad]

I find the Archimedean Spiral too mechanic and not natural, which makes sense condsidering what Archimedeas invented or discovered. The Fibonacci Sequence is found everywhere in nature. However, I believe the Golden mean was known well before Leonardo of Pisa (Fibonacci). The Greeks figured this out over 2,000 years ago, it's in their buildings!!

[RustyLaidlaw]

I think the people of the 15th century knew whole lot. At least more than I know, anyway. I have a book of Italian medieval ironwork and it blows me away. A whole different level.

Yes, the golden spiral does look a bit mechanical, but tweaking around with the proportions can make it look very pretty and natural. I've tried a lot of different methods, and I think it's a very solid scroll to begin with, and build other jigs off of.

[Old N Rusty]

See the book,"The Golden Section" by Scott Olsen.ISBN 1 904263 47 X

[ThomasPowers]

Any one try just getting some of the natural spirals and photocopying them and then using that to build a jig from? Most modern photocopy machines can enlarge items easily.

[Rick Barter]

A couple of items. The scroll tool can be made of mild steel, but should be thicker and wider than the scroll to be wrapped around it. After offsetting the fishtail, the end of it is cut at right angles to the stock length. When you start the bend, if you're right handed the offset is facing left. If left handed, it faces right.

It is difficult to free hand a scroll to look like another scroll, even if based on the 'golden rectangle.' Archimedes had another way to lay out a scroll, and on paper, it looks kind of like War Room coordinates...concentric circles and criss-crossed lines. We should realize, however, that neither the golden spiral nor Archimedes spiral is like a chambered nautilis or a snail shell. They have different ratios. Some are tightly scrolled with less negative space between convolutions. Some are "loose." Yet both are legitimate scrolls. A good designer can make a quite open scroll using the proper sized steel, and the negative can dominate the positive.

One can make scrolls all day long on paper, but then what? To make it of steel, you must know how to free hand it. If you transfer the paper scroll to a steel plate or table, you can attempt to match your tool or scroll to the layout. I suggest that this is a pain, that it is time consuming, and that it will be a "back and forth dance" of bending and unbending. Drive ya' crazy. It is easier to make a scroll form to your liking without using a pattern. Make the tool a little oversized, so that you can make a soapstone mark on top of the tool to show you where to stop bending. In that way, the finished scroll will fit your designed module.

The catch is to forge and watch the negative space grow in an exponential fashion. Arithmetic was not my long suit in school, so I'll try not to get lost explaining "exponential." Another way to say it might be, there is a constant rate of growth from the center, and it may be more easily seen in the negative space that the positive. If the negative looks good, then the positive should look good.

One way to check the scroll is to draw radiating lines from the center outward, and between convolutions. As you get away from center, each line gets a little larger. If the lines stay the same length, you're no longer "growing." If the lines are getting smaller, whoa! You can drop back to see where you've started to go bad, and you can open it a bit from that point and rebend if necessary.

How can it be done, If you're not using math and geometry? By practice, and by realizing that you're involved in art and craft, not just math and science.

There is another type of scroll that we see in early ironwork. Once you get a little ways from the start in the center, the negative space distance between convolutions remains the same. The negative space does not expand. On this scroll, you will use more stock than on Mother Nature's style of an expanding scroll. Is this Archimedes spiral? Perhaps.

Another scroll which I personally like, is an oval or elliptical scroll. These were used in old time ironwork. They are a little tricky to forge, if you are used to forging with circularity.

Another consideration. Let's nit pick. You want the outside of the bend to be "flat," a bent plane surface, because of the way the tool is used. But when you bend flat stock, it concaves on the outside of the bend, and the corners stay high. I'm talking about cross-section, and this is a concomitant of forging. My old horseshoeing teacher used to yell at us, "It draws on the outside of the bend, and it upsets on the inside of the bend!" This can be overcome by using common sense forging. If you draw the hot stock lengthwise through a bottom swage in conjunction with a top fuller, you can forge a mild concavo-convex cross-section BEFORE BENDING THE SCROLL JIG. When bending, have the convex side up and it will become the flat side upward instead of concaving.

When you make the finished scroll on the scroll form, it should have a little of the concavo-convex, because it is a nice aesthetic.


"Practice doesn't make perfect. Perfect practice makes perfect."

http://www.turleyforge.com Granddaddy of Blacksmith Schools

 

This is so well-said and helpful.  Thank you, Frank!

[JamesBBrauer]

Rusty, you might like the Curvemaker plugin for Google Sketchup.  I haven't looked at the code, but suspect they use recursive functions to create series like the Fibonacci.  Then they modify some of the coefficients to let you create all sorts of other spirals.  I used the tools to create 3D models for CNC routing wood.  For metal it is a quick way to study proportions and visually experiment with spirals.  I've cold bent some spirals, but just don't have much occasion to hammer them out.  Getting a fair curve in hot metal isn't an easy thing to do.