guru : |
Tonights demo will be about spirals and scrolls. Specifically laying them out and making jigs. | |
guru : |
I generally just bend scrolls by eye but many need to lay them out. The easy way is on a grid like this. | |
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guru : |
This grid is a set of concentric circles 1/2" (13mm) apart and divided into right angles, 45's and 22.5's | |
guru : |
The scroll is laid out in equal steps. Starting at the center | |
guru : |
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guru : |
Here we have placed a point on each 90 and 45 degree line moving out one circle at a time. | |
guru : |
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guru : |
If you put a point on every dividing line as you move out the circles you get a faster more open spiral. | |
guru : |
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guru : |
But you can also skip more than one dividing line and get a slower tighter spiral. | |
guru : |
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guru : |
Here we have skipped 2 lines between each point. When we layout the scroll we can divide the "skipped" lines into thirds to make a smoother spiral. | |
guru : |
Using the same grid you can layout any kind of spiral to any scale. | |
guru : |
Once you have your spiral scrolls laid out you will want to make a jig if you need to make more than a few exactly alike. | |
guru : |
There are several methods of making scroll jigs or benders. | |
guru : |
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guru : |
This simple jig is made of 1/8" angle iron and 1/8" by 1" flat bar. It was used to make identical scrolls in 1/2" square stock. | |
guru : |
The image is out of shape due to the rectangular image being forged into a square. . . | |
guru : |
This jig was used to make two ends of an "S" scroll that were different sizes. One end was pulled around to a chalk mark roughly at the cross bar, the other was pulled all the way around. | |
guru : |
Using the same jig for both ends gives a pleasing sense of continuity. | |
guru : |
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guru : |
This jig is made from a forged "fish tail" scroll. The tapering stock forges more naturally into a scroll if you are working by eye. | |
guru : |
The fishtail also sticks up higher than the other parts so that you get the effect of a stepped or progressive jig that can make more than one turn. | |
guru : |
This jig is also welded to a piece of angle iron so that it can be clamped in a vise. Vise mountable tooling is one of the handiest things you can do in the blacksmith shop. | |
guru : |
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guru : |
This is a scroll bender attachment for a Hossfeld bender. | |
guru : |
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guru : |
It works by having a hinged portion that swings out of the way so that the bar to be bent can be inserted. | |
guru : |
As the stock wraps around the bender the hinged portion can swing in and a spiral of more than 360 degrees can be bent. | |
guru : |
Normally these production benders produce an ugly flat end on the stock. However, if you are forging a bean end or fishtail on your scroll you can make a bender like this that accepts that style end. | |
guru : |
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guru : |
Questions? |
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flatthumb : |
looks like the Golden Mean in a spider web - fascinating! | |
Doug : |
Is the stock bent while red hot when making a scroll on jigs like this? | |
guru : |
Doug, It can be bent hot or cold. Normally the tight center part is bent hot and then the rest cold. | |
poorboy : |
when bending by eye or your first scroll for the jig do you use a set of posts, a bending tool of some sort ? | |
T-Boat : |
the Golden Mean can be found all over nature, flat | |
flatthumb : |
Where did you pick this up Guru? It's a lot simpler than laying it out with rectangles.:) | |
joe : |
found this a while back, might be of interest..freebie.. GRAPH PAPER PRINTER can be downloaded from the author's website : http://perso.easynet.fr/~philimar/ | |
guru : |
FT, all true spirals are mathematically progressive. Those who try to fit everything into those rectangles are fanatics. | |
poorboy : |
you indicate one of the first jigs you showed us was 1/8" thick, how heavy of scroll material can be worked on an 1/8" jig? | |
guru : |
On that jig I bent 1/2" square. The first 4-6" were bent hot. The rest cold. | |
guru : |
Most of my scrolls get bent over the horn of the anvil or just curled up hot with a hammer. | |
guru : |
I only make jigs when they have to fit a specific space and you need more than 2 or 3. | |
Chris : |
Hi Guru - I downloaded a picture of that first jig, and don't quite see how it's used. Could you elaborate on some of the details? | |
guru : |
The Hossfeld type is expensive to make OR purchase. However, if you are going to make a couple thousand cold bent scrolls it pays off quickly. | |
guru : |
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guru : |
The "S" scrolls made with this one had to fit existing wooden brackets that made a triangle. | |
guru : |
After scrolling the S's were fit into a triangular for the final fit. | |
guru : |
This was part one of two. Bill Epps will be doing the second half, "Scroll Ends" in a few weeks. | |
guru : |
These and several other benders can be seen in our Benders article on the 21st Century page. | |
guru : |
If there are no more questions, I'll say good night folks! | |
