Wednesday, December 09, 2020

Prototyping

I've commented here before on the 'Iron Triangle' (1). Over the years of this blog, there have been a lot of commentaries related to the 'Artisan's Way' : where ideas come from, and how these get fleshed out from Inspiration, to Concept, to Making.  There have been discussions of the many, many facets that any individual must undertake (and usually attempt to become proficient at) to turn an occasional hobby activity, into a self supporting business. 

This segment is going to take a look at something so often completely forgotten in the creation process - prototyping. 

There is an old parable. The Japanese master was asked : How long does it take you to make a tea bowl? His answer : Twenty minutes to make the bowl. Twenty hours to prepare the materials. Twenty years to learn how. 

Now too often in our modern world, all people see is the 20 minutes. True master's skill looks effortless. People who do not work with their hands do not recognize the endless effort that is required to acquire that level of knowledge, skill and experience. (2) 

In a perfect situation, an Artisan would have some huge stockpile of Knowledge, Skill and Experience that would allow them to effortlessly (??) to select and transform raw materials into a given object.

 

But let me tell you - that is just NOT how it works.

 

I had a very loose concept for a large sculptural piece, centered around a large green glass wine carboy I had scrounged years back. I was thinking of a kind of fantastic 'Audry Two' plant form, with the curved flask shape, turned upside down at it's heart. In working out the overall form, I was intending to make a number of tall S shaped elements, using a number of the glass 'bell' jars I had purchased a long time back. (3)

Initial 'hen scratch' concept drawings

This glass flask was quite large, about 45 cm ( * ) at its widest and about 60 cm tall. Unfortunately, the years being stored in the unheated workshop had placed a huge amount of stress into the thin glass. While I was tracing around the piece to create a full sized layout, the vibration of my arm over the surface proved enough to crack off the entire base section of the flask. Obviously I will have to come up with quite different overall design from the initial concept.

I have often poured through 'Art Forms in the Plant World', which is a shortened overview of the work of photographer Karl Blossfeldt (4). With the loss of the large flask, I knew I would have to include some additional organic elements beside the bell jar 'flowers'

Image by Karl Blossfeldt


One of the images I have been stuck by is the one above. Described as 'Common Chili-nettle. Seminal capsules'. The source image is roughly 23 cm tall, 'enlarged 4.5 times', which would make the actual plant segments about 5 cm long. 

Those who have followed my past work have seen I have done a lot of pieces where my starting materials have been structural steel : pipe, angle and channel. Angle, when flattened, easily creates an initial stock with a raised central rib on ones side (and corresponding central depressed line on the opposite). I know this would prove a very simple way to mimic the scalloped surface on the outer, twisted, capsule parts of the seed pod. 

Although there was not clear detail of the interior parts of the seed pods, it was clear that there was some kind of shaped surface inside. This would only be glimpsed at through the gaps in the exterior spiral casings. Even still, including some kind of additional detail to the form I considered important, in terms of creating different visuals at differing viewing distances for the observer. (5)

The central rod shape, which would extend to make the final terminal, was chosen as 1/2 inch ( * ) round stock. As seen in the source image, this would end in some kind of pointed shape, with a taper drawn down towards it. I made a first attempt at this, using an slightly upset point, which was then hammered into a triangle shaped bottom tool. This resulted in a more or less leaf shaped, but three lobed form, flattened to one surface. I was able to make a more or less tri-symetrical shape by using a rounded edge straight line punch, forcing the flat side back into a gap left in the vice. In the end I was not happy with the overall result however. 

So I made a second version, this time starting with a longer square point. I then punched in a line down each of the flat sides of the square as an additional detail. I had started with a fairly generous length, but had cut off the first terminal made, leaving me with about 50 cm of material.

Start of the core part

The first idea I had for creating the core portion was to start with three pieces of smaller angle (1/2 x 1/2 x 1/8 thick) cut to 20 cm length. These were tack welded (admittedly fairly rough!) in three places, both edges, to splay out from the central rod. For the prototype, I used a simple 'cheat' on the ends, just cutting diagonal lines with the band saw for the ends. The lower portion were cuts at about 45, the upper a longer taper. 

Core - twisted

My idea for all this was to twist the fabricated bundle. Nice *idea* - but how exactly do you *grab* that kind of shape? Holding the lower edge (first cooling the bottom 3 cm or so) proved easy enough. Getting a secure grip on the *top* section to apply the considerable force required proved a real challenge. The overall shape presented by the three outward spreading V shapes of the angle was just too much like a cylinder, and my adjustable twisting wrench just kept slipping off! (6) In the end the result of three separate heat to twist attempts was only a 1/3 rotation, as seen above. (With the addition of considerable swearing in process.)

Preparing the outer wrap parts

For the outside wraps of the capsule, I prepared three pieces of wider (3/4 x 3/4 x 1/8) angle, each 40 cm. Again the ends were diagonal cut on the band saw. Here one end (the lower) was pointed to about 45, but the upper was cut to create a reversed shape (so from the ends back towards the center). Then each was flattened, but leaving about 5 cm on the lower end left at the starting 90 degree shape of the angle. These ends were then forged to both offset that tip to about 65 degrees, but also to add a Z shaped offset. (Clearer in the image above?) These pieces were then MIG welded around the lower end of the twisted core bundle. 

Forming the outer capsule

After attaching the outer pieces, the resulting splayed construction was simply far to large to fit back into the forge ! (7) So although tedious and offering a quite different kind of heat application and control effect, I used my oxy-propane torch to apply sequential heat, allowing me to alternately twist around each of the three bands. I used a piece of larger diameter steel pipe as a central form. This allowed me to concentrate on keeping the spacing between the individual bands (fairly?) regular as I worked around and up. Of course on cooling the cylindrical wrapped bands, these tightened around the form. I had enough space at the base to fit a long piece of 3/8 against bottom edge of the pipe to drive it out. 

Completed seed pod element

The last step was forging in the upper part of the three outer wraps. This requires a lot of lighter, controlled blows, as all the pieces are being both pushed into, but also around, to the core as you forge them. You can clearly see the difference in shape caused by this process, creating more of an elliptical profile overall. These upper ends were left 'forge tight' rather than later being spot welded together.

Element mounted

For this project, I will be making the 'stems' of each element out of re-profiled channel (1/2 x 1 1/2 x 1/8 used for the prototype). There are two cuts made in the end to separate the three 'lines' for this element about 10 cm. For the prototype, each of these separate pieces were forged to slightly different shapes : spread wide then spiral curved (right above), flat offset to one side then an open spiral (left above), drawn to a long square point with reversal curve (back side out of view). The main run of the channel is forged using the cross peen along the wider bottom side, into a recessed half cylinder bottom tool. This results in curving that flat side, also narrowing the gap between the two shorter sides (so more of a wide U shape). Next the opposing sides are carefully forced downwards and around - until the original two open edges touch. The net result is a very organic, slightly distorted pinched cross section, with a visible seam line running along one side. 

For the initial prototype, the two elements (pod and stem) were joined by simply driving the tip of the core rod down into the central gap remaining in the stem and allowing to tighten on cooling.

 

The creation of a prototype, even from skilled and experienced hands, almost always indicates forging problems to solve and modifications required for a more elegant result :

  • I will likely abandon the use of angle in the core bundle. It has proved too difficult to manipulate - and to control the shape generation. 
  • Instead, I will switch to using a bundle of small round rods, still spiral wrapped around that central core. Buy individually cylindrical pointing the upper ends, I will be able to also create an additional element, suggesting flower stamens.
  • The prototype illustrated how starting lengths for the bars needs to be adjusted if I want to retain the same proportions as the plant source. Ideally I would like this element to be considerably longer in relation to its width (as the source is). Using a ratio 'twice the length for the wraps as the core' proved correct for this version, but only a second prototype will show if this remains the case for a longer finished element.
  • The bottom edge of the outer wraps were formed by simple diagonal cuts. To mimic the more slender lines of the plant, these pieces should really be forged to long tapers initially. 
  • A bit more care needs to be taken controlling the spacing between the individual outer wraps as they are coiled around. It is only through these gaps that the details of the core shapes are glimpsed.  

 

An important consideration also is revealed here : The vast difference between 'one of a kind' artistic objects, and more standard, repetitive objects. I spent a total of four hours generating this prototype element. With the changes suggested, I will certainly need to make a second, hopefully not taking quite so long (and with considerably less frustration). This represents a huge gap in both effort, and time, between 'I think I can make that' and 'I've made that before'.  

Time is money. 

Skilled Time is expensive.

A couple of things to bear in mind...

 

( * ) In Canada, steel stocks still come primarily in Imperial (inches) sizes. In an attempt to keep 'up to date' length measurements here are given in current Metric dimensions (cm).

1) You can have it CHEAP, you can have it FAST, you can have it GOOD : pick ONE. 

2) Of late, increasingly I am finding that 'quick fix' methods are coming to dominate public perception. This of itself is hardly a new problem, especially in Western / North American culture (I clearly remember when Eastern Martial Arts caught the fascination of the general public in North America. Few caught the subtlety of 'If you can snatch the pebble from my hand' (although I'd bet most reading are familiar. increasingly, I am finding 'I saw it on the internet' becoming a standard statement of the source of 'knowledge'. I consider this almost frightening in implication, especially when coupled with the quite obvious increasing lack of 'critical evaluation' by the viewers. The number of YouTube hits someone has accumulate is absolutely no measure of anything, save perhaps 'instant celebrity'.

3) This illustrates the glass bell jars : 

'Glass Jar Holder' : 1997

 I had gotten these as a clearance item from Ikea, back in the late 1990's. There were a stock of these (at a stupid reduced price), in red / blue / green colours. I had bought ALL they had available. Currently I still have about 45 of these still boxed away!

4) 'Art Forms in the Plant World' is available as a Dover reprint. This a selection of the larger volumes of close up, fine detailed, black and white images :

https://www.goodreads.com/book/show/825481.Art_Forms_in_the_Plant_World

5) Going to stress this overall approach to design. Ideally any object will become much more interesting to the viewer if there are levels of differing 'visual information' to an object as one approaches from some distance. The overall lines will be seen from far away, ideally presenting enough flow that will encourage the viewer to come closer. At an intermediate distance, more of the form of the individual elements becomes seen (the shape of the flattened angle for example).  Closer still, and aspects like surface texture, or 'hidden' details (like the underlaying pod cores here) can be seen. 

6) In retrospect, some kind of special twisting tool, likely specific for this single application, would be needed. Likely a bar with a suitable sized punched hole in the center (to allow passage of the round core rod). Then three prongs attached, each spaced to fit down into the gap of each piece of angle. (??)

7) I certainly would have been able to correctly heat this large bundle in the coal forge - if I had been using it. I don't have any residual heat in my workshop, so by this time of year I switch to using propane when possible. As much for space heating as effective forging. (the 'Dark Side of the Forge' for me!)

1 comment:

David Robertson said...

Using a chain wrench could be of value to twist the multiple bars. Essentially roller chain like bicycle chain wraps around any shape which is welded to handle so that chain tightens as you turn. Some are set up as vise grip clamping mechanisms.

Might make the multiple easier and more uniform to handle.

 

February 15 - May 15, 2012 : Supported by a Crafts Projects - Creation and Development Grant

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