Flint knapping, 3D printing and primary school workshops

I have some workshops planned aimed at primary school children studying the prehistory of Britain. Following the theme of this blog, one of the activities is to bring together the components necessary for the kids to make a Bronze Age arrow. Rightly or wrongly, I am a little cautious about letting small children loose with flint or glass arrowheads so I thought I would get some 3D prints. The flint originals were a Neolithic leaf shaped example and a Bronze Age barb and tang arrowhead both produced by John Lord for Elizabeth Healey’s teaching collection . These originals were scanned in by a colleague Tom O’Mahoney.

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Tom also scanned one of my glass barb and tang arrowheads to see how the scanner would cope with a reflective and transparent material. This example had to be covered in talcum powder before scanning.

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After scanning, two prints of each of the flint versions was produced for me by Ed Keefe from the print unit at Manchester Metropolitan University (ManMet).

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The first two examples on the left have some horizontal lines running across. Ed described this as similar to when a photocopier is running low on toner. Consequently he printed them again in the more transparent material. The second two are excellent ‘plastic’ reproductions of ‘original’ flint reproductions. However, the most impressive aspect is the price. Because prints are priced by the cubic centimetre each arrowhead worked out at £2.50. Full colour versions would have cost £3.50. My scans can be uploaded to sites such as Sketchfab or Thingiverse and therefore downloaded free of charge by teachers with the print costs being minimal.

The workshops are still at the planning stage, but I have been impressed by the results and the prices for this process. I would certainly recommend the 3D print facility at ManMet to anyone who thinks the process may be useful to them. Ultimately though, it depends what the kids think!

Karl Lee pressure flaking glass

This is a link to a short video of Karl Lee pressure flaking glass . It is of interest to me because it illustrates how he uses his knee “like a vice” to remove the flake. The large piece of glass was modern, and probably a table top. This is the end result.

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Manchester, rain, three Kimberley Points.

Today has been miserable in Manchester, an ideal day for being sat behind a desk, sorting out all those jobs that need doing. I found myself in the backyard, in the rain. I have been inspired since my visit to the museum earlier in the week, and think I am getting it. Consequently, I took three points made previously and reworked them, or refined them to bring them more in line with the museum examples.

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I know you shouldn’t have favourites, but it’s the middle one. Then the one on the right and then the one on the far left. I actually learned the most from working on the one on the far left, and then was able to apply that learning to the other two. Essentially my edge control is getting good. This is allowing me to get flatter points, and in turn serrate the margins more subtly.

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This is one of the museum examples with a broken tip, angled to show the degree of retouch. You can see how the flaking really penetrates up to half way in creating a ridge or spine.

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This is my version. Shape and size and margins are all good. The needle like tip is needle like, the area to improve is fully invasive retouch. It needs to penetrate further in. I therefore need to take a leaf out of Nick Overton’s book and sort that out on my first pass, then bingo!

 

Ishi the last Yahi: a documentary history.

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Many thanks to Elizabeth Healey for lending me two really interesting texts. This post is about one of these, the above book which as the sub title indicates, documents the recorded aspects of Ishi’s life. I like this photograph because it shows Ishi as a person, not simply “the last Aboriginal Savage“, and because of the focus of this blog, of particular interest here are the documents recording his toolkit.

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The above inventory is presented on page 184. Number one is an Ishi stick, although from a differing culture group and earlier period than Ishi. The emphasis is on length and I haven’t fully grasped the bio-mechanics of how this might help with pressure flaking. Perhaps I will be able to explore this in a later post. Number two is a long piece of wire (3/16 ths of an inch / 4.8mm) that has been hafted and sharpened. This seems to be a very similar tool to the Australian aboriginal No 8 wire (see here)  used for making Kimbnerley Points. Number three is described as a slender nail hafted, sharpened and used for the finer work of notching (Heizer & Kroeber 1979: 170). Finally there are examples of Ishi’s work, with the longer pieces made as show pieces. Here again  is a parallel with the Australian aboriginal Kimberley Points, with the larger glass examples becoming media for trade and exchange, and particularly valued by European collectors. These pieces are really interesting in that they capture and embody a particular indigenous skillset, but it is a modified and abstracted version to take advantage of new materials that allow the marshalling of different qualities (size and transparency).

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This final image shows Ishi’s pressure flaking method. Most modern knappers I have observed use their thighs in order to provide stability and generate power to remove the flake. I have some good footage of Karl Lee doing just this and I will edit and add this very soon. I wonder if this was Ishi’s actual knapping position, or staged for the photograph in order to show the position of pressure flaker in relation to margin? This choice of bodily positioning is fascinating in its own right and again needs more exploration. Finally, on Youtube I like Flintknapper Jimmy and his approach to understanding how Ishi actually knapped. From a museum visit he has looked at Ishi’s actual tools, preforms and points in order to interpret his process. He uses an indigenous toolkit as well as a glass cutter, because that is what Ishi did. Look at his pressure flaking tool in comparison to the photograph presented above  (Ishi’s knapping approach). See what you think.

Heizer, R.F. and Kroeber, T. eds., 1979. Ishi, the last Yahi: a documentary history. University of California Press.

 

Prof. Eleanor Casella’s reference Kimberley Points

This morning I paid another visit to the Manchester Museum and Gareth Frier was kind enough to dig out their Kimberley Points collection for me. My aim was to compare and contrast two of my own points with the museum originals. The two points in question are produced from the same piece of period glass bottle (see here and here) and are headed for Eleanor Casella’s teaching collection. Long story short: one of my points is a good replication, the other less so.

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The above right is the ‘less so’. The point on the left is the original and as can be seen, it is much more refined in its retouch. They are keeping their retoucher much sharper, as it states in the texts, and it is interesting to see what that actually means in practice. Consequently, the original sits flatter on the paper in spite of its twisted longitudinal profile, and I now think that it is this flatness that allows more detailed edge serrations. I went in thinking it was edge angle that would be different, but it is flatness, which leads to a reduced edge angle and ultimately thinner margins that can be serrated. I have left my version with Eleanor as I said I would drop it off today, but I would like to continue flaking in order to flatten it, if she wants me to.KP2

I am pleased with this second one. To all intents and purposes it fits the Kimberley Point criteria. The point on the left is the original and it has been made from a thick (at least 7mm) piece of glass and completely flaked on both surfaces. Mine on the other hand is made from the side panel of a glass bottle and has some original ventral surface left. This is true for almost all the other pieces, though usually to a lesser degree. I have also left some original dorsal surface to keep the lettering because I like it, and other examples discussed had this. I am pleased to say that this piece would be at home in the box with all the other originals.

Neolithic Milk of Magnesia interlude.

I had the opportunity to have a wander around Chorlton Ees one morning last week and came home with quite a few pieces of old glass recovered from the roots of fallen trees.

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This lovely blue piece in particular caught my eye and I like to think it is the base of an old Milk of Magnesia bottle.

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As you can see it is chunky and I wasn’t quite sure how well I could reduce it. This is because it is both narrow and thick and I was worried that I may run out of width before it was adequately thinned. Anyway, today has been a beautiful day here in Manchester and I got to spend a couple of hours outside playing with it.

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I am pleased with the result. It has become a Neolithic leaf shaped arrowhead, similar in proportion to some of the stone examples I have seen. The edges are sharp, the tip is good and it is fairly symmetrical.  What really makes it stand out though is the lovely blue colour. When Nick Overton sees this photograph he will immediately focus upon the very, very small section of original surface left in the middle. All I can say Nick, is: “when a pickpocket meets a saint, all he sees is pockets!”.

 

A test run for the Ishi Stick, and a ‘tough break’

Since getting together with John, Rob and a few others for our regular knapping sessions, pressure flaking has become a bit of an obsession for me-in particular, working pre-cut glass slabs into points of various sizes.  Key to this is taking a good first set of pressure flakes, to remove all of the original surface-an end result that is ‘fully invasive’ has become somewhat of a holy grail for me over the last few weeks. To that end, I decided to make an Ishi stick out of a chair leg John donated-a number of the knappers on youtube, including palaeomanjim, seem to use them for their larger pressure flake removals, and the general idea is the longer handle allows more power to be applied, thus removing longer flakes.

The construction of the Ishi stick is very similar to the Ishi style pressure flakers John discussed a few posts ago-I split the lower part of the chair leg, cut a groove for the nail, and carved a collar to locate the copper cap, and another recessed section, which I bound with string to secure the whole thing. Initial attempts to use the Ishi stick were a little shaky, and overall it felt a little odd, as the long handle runs up the forearm and braces the wrist.  However, once used to it, it allowed a more controlled application of power, and resulted in some excellent long pressure flakes.

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Detail of the Ishi stick at the business end

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The Ishi stick (top) and the Ishi style pressure flaker

However, as the often uttered phrase goes, with great power, comes great responsibility.  In this case, a responsibility to pick the correct platforms, and a responsibility to control the removal process and avoid unnecessary force.  On this first outing of the Ishi stick, it was a lesson I learnt the hard way, breaking every piece I started. But, there is a lesson to learn in every mistake-on reflection, all of the breakages occurred at the same point in the point-making process. I had successfully removed the plate glass surface with the first pass of pressure flaking using the Ishi stick, and I had returned to take a second set off, using the high spots left in between the pressure flake scars taken in the first pass as platforms. I used both the Ishi stick, and the Ishi style pressure flaker for this stage on different pieces, but both resulted in the piece ending in two bits.

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Good invasive removals from the blank, but both broke in the middle

At this moment in time, I have yet to decide whether this is because I am putting too much force into this second set of removals, because my technique is exerting too much ‘bending’ force on the piece (exerting a force along the axis of its thickness, as opposed to across its width), or whether the pad I am using for pressure flaking, with a groove to allow a free pressure flake removal, is not offering enough support.

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My pressure flaking pad and one of the broken pieces. Is the groove in the pad too big to support a piece this size?

So our next knapping session on Thursday will see a new three-fold approach: 1) Removal of the first set of flakes using the Ishi stick and pressure flaker pad. 2) Good platform preparation (or re-preparation). 3) Removal of second set of pressure flakes using the Ishi style pressure flaker, and a new pressure flaking pad with a smaller groove, so as to offer extra support.

As John said at the end of his last post, I am sure we will be making a few more of these-for me, it’s fully invasive or bust!