Category: bams medal project

final submission

i had palpitations when i went into the studio early in the week and saw how much effort everyone was taking to arrange their spaces, final show style. it hadn’t occurred to me that we should be doing anything along those lines. i was still at the making stage, just hoping to have finished work to present and i decided it was a better use of my remaining time to keep working in that direction.

i did make an effort to present my work gallery-style, with mounted statements, separately from the background material/samples. the layout isn’t quite how i envisaged but i hope it encourages the viewer to investigate the work without being overwhelmed by the additional supporting content. the biggest thing bugging me about it is the ugly, ugly black speaker cable running to the radio. on reflection i wish i’d investigated wireless audio setups, but as i had to keep the ipod external for switching on and off it would never be perfect in that respect.

i also attempted to lay out the background work in relation to the final pieces – here you see the radio research behind the work. i wasn’t sure whether it was okay to use a poem (not mine) as my statement for this piece, but it was written by a friend as a response to my initial ideas, a loose kind of collaboration, and it explains the piece much better than i could.

i wanted to present my ideas sheets next to the medal because this is my least complete work and i feel it needs the additional background information to convey the intent of the piece (whereas i feel the intent is visible in the work for my raw & readymade projects, which pleases me immensely). i decided to present the book with the box lid open for the assessment as i didn’t want any confusion over whether the book was supposed to be read or merely looked at.

i decided to go for “less is more” in the way of supporting work, hoping to keep a clean/clear presentation. my sketchbook is particularly bare/poor for the first term raw & readymade brief because i really hadn’t figured how to make the format work for me – i rarely enjoy drawing and the blank page intimidates me. over the year i developed a practice of starting each project with a new, thin, book and using it as a combined sketchbook, journal and sample book. this scrap-book approach is one i’ll continue with as once i’d figured it out it worked really well for me in my field projects.

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the resin casting blues

got them too 😀

the resin cast of my medal that i was hoping to present at the assessment is beyond rescue. the basic cast was pretty sound – much better than i was expecting from my first ever cast in my first ever 2-part mould. i realise this is a process that most makers on the course would be familiar with from foundation and/or first year, but it was totally new to me and took a lot of getting my head around.

when it clicked i was a bit *woah* about the possibilities it opens up – any analogue method of making reproductions presses my buttons.

despite my sampling the cast didn’t come out as i’d expected. all my previous samples had been made with open silicone cake moulds, which dried to a fine consistency where it touched the mould. the cast was much more pebbly in texture (perhaps due to the granular finish on the printed medal), the brasso i’d been using to finish my samples just couldn’t touch it. the finish was so rough the piece barely looked translucent so i figured best skip straight to a finishing coat of resin.

the problems with this being a) it curing in time for the assessment (my samples have taken 36-48 hours to even begin to cure to the surface despite added gentle heat) and b) the effect of an additional coat obscuring the text around the edges, that i’d been really pleased to be able to cast (not perfect but legible). when i went ahead it was visible that the resin was cloudy to the centre, something i’ve not experienced before. maybe it isn’t fully cured or a difference between casting in a 2-part mould to an open one?

more expected, i got a couple of large bubbles, under the worm and another terminal one right at the top of the mould between the pouring and air escape tubes. also as expected the fragile letter sections of the mould have come away in places, so i’d need to make a new mould to attempt casting again (although i could run more experiments with the first mould).

i think my biggest problem has been the time taken for the epoxy resin to gel and cure – at least 6 hours for the former and 48+ hours for the latter. it doesn’t allow for the gradual manipulation you can do with a faster setting mix. still, i do like some the effects i’ve managed to achieve in my samples, so i think (resin) casting is something i’d be interested in revisiting at some point.

3D modelling and beyond

i’m very happy with my sls print (selective laser sintering = powder printing). slight banding on the upper and lower surfaces and some faceting on the inside faces, but these are both more obvious on the lower half and will hopefully be diminished in the casting process (or less obvious in clear resin). the colour of the nylon is stated as white but against a brilliant white backdrop you can see the warm tone, which should work well with the natural colour of the silk inclusions. the printed piece is reassuringly weighty and has a texture my daughter described as “like extra strong mints” 😀

i’m delighted with the crispness of the detail in the text and moth image. this is the clearest difference of using a powder bed printer – which requires no additional supportive structure – compared to the makerbot prints which can never really be cleaned of the tangle of supports.

the pieces fit together perfectly and the dividing line around the edge is barely visible. my only reservation would be how easily the surfaces collect random fragments of fluff and dirt.

i was worried that the delay i experienced in purchasing the software and a pesky bank holiday weekend would mean i wouldn’t be able to progress the project beyond this stage. but 3dprint-uk surpassed their lead time estimates and martin managed to squeeze me into the workshop before the move and i made the first half of my two-part silicone mould today. hopefully the second half will be dry enough to bring home before the weekend, and the slow drying (but non-smelly!) resin i have will cure in time for the assessment.

i have very little time to experiment with the material or the mould and it may turn out i need to do further work over the holidays or when we restart in the autumn, but i’m determined to get this piece finished. even if the casting goes to plan i’m expecting some shrinkage in the resin, which will entail scaling and reprinting of the upper half of the medal to ensure the perfect fit i’m after.

and if i don’t get a usable result from the casting i’ll be left to present the bottom half which i expect to be markedly grubby from the mould-making process – let’s hope it stands up to a vigorous scrubbing with a toothbrush…

3D modelling: part 2

following on from here.

no matter how nicely my rhino models rendered, i couldn’t get them into a printable state. boolean operations were temperamental at best and often failed, apparently at random – working one time and failing the next with identical objects. my models were teeming with horrible jagged edges.

moment of inspiration came to my rescue. it was written by the same person who wrote rhino and all the functions are familiar, but this is a pared down version aimed at the beginning modeller which excels at producing “hard surface” models – ideal for 3D printing.

modelling in moi

here you can see my finished model along with some of the construction elements. the tube on the right is for cutting central holes for the magnets (larger 6mm diameter ones to increase the “grab” between them and hold the heavier final materials). much as i would have liked to use a heightfield image for the top i couldn’t get it to work so i resorted to extruding my line drawings and punching details through cookie-cutter style. this process still required a fair amount of trial and error – i was unable to include some detail i’d have liked on the moth’s body.

i flowed the moth shape across the surface at top left, constructed from the same curve initially used to create the medal profile, after which i just slid it across onto the top. having tried this process in rhino i was left with the eternal boolean union problem – looks okay in render, looks awful when taken into makerware to print – but moi joined them perfectly without complaint.

my plan had always been to powder print the finished model, but i discovered the printer at college had died a while back. the pressure of sending the job out to a commercial printer really focussed my mind – no opportunity for experimental test prints. 3dprint-uk looked like my best bet price-wise, with the added benefit of having an automated quote system that previews the validity of your model and offers some basic fixes. when your two-piece model shows up as having several more you know it has a chance of failure. unfortunately having a test print come out okay on the makerbot – which my glitchy files did – is no guarantee it would also work on a different printer.

i used a piece of software recommended on their site – netfabb basic – to check and repair my stl file. initially it came up with several holes – easily fixed – and thousands of inverted triangles – not so easily fixed in the free version. it turns out this was a result of exporting the mesh with the maximum number of polygons, once i reduced that number down i managed to make an honest-to-goodness valid file \o/

while this process has often been a frustrating one i feel i’ve come a long way in a relatively short period of time. i’ve identified the modelling software best suited to my needs and abilities, with the bonus that what i learn on there should be transferrable to rhino if i find i need something with more features in the future. i did try a number of other pieces of free or trial software as well as taking advantage of autodesk’s student downloads to trial maya and mudbox, but each had its own steep learning curve. in terms of producing printed finished pieces moi works best for me. the tutorials on 3dprint-uk have been very helpful in narrowing down what makes a valid model that has the best chance of printing as expected. i feel well enough equipped now that i would happily use 3d modelling and printing in future work.

can’t wait to get my print back and see how i did.

woven silk

so many lessons follow from taking the sample off the loom…

here’s how it came off – coarse and stiff due to the sericin remaining in the threads.

degumming involves gently simmering with an alkali and a surfactant (soda ash and synthrapol respectively). i used 1 tbsp soda and 2 of synthrapol and cooked for just over an hour.

following degumming 2 things are obvious : the fabric is mush softer and more flexible; it’s also sleazy (i think that’s the technical term :D). the weft threads slide a lot on the warp. part of my degumming was squeezing the cloth between my fingers to remove the jelly-like gum and the threads packed down as you can see above. on drying they were even slidier – they pack down into half the length of the warp. this tells me my sett was too wide – i didn’t have enough warp ends to make any kind of balanced cloth – and the slipperiness of the cleaned silk makes this even more apparent.

the other thing that jumps out is how un-shiny the finished cloth is, especially when compared to the naked warp threads which positively glow. i tried to catch the difference but a photo really doesn’t do it justice.

a couple of changes to my next sample suggested themselves. i doubled the number of warp ends per inch (4 per hole/slot), these threads gather together on the loom, making for a pronounced stripe in the cloth, i’ve no idea if it’s possible they’ll spread themselves out during finishing. i also increased the weight of the weft, in the hope that might produce a more balanced cloth, rather than the weft-face i’ve ended up with. i’ve done a short section with the original weft (2-ply) another with 32-ply to match the 32 threads through each hole and slot (4 x 8-ply threads), and another section with 16-ply (the easiest for me to produce from the threads i already have). i’ve also beaten the weft in harder.

the next sample just needs hemstitching before i can cut it off the loom. something else i can look at is degumming before weaving. the degummed threads are really incredible and more than justify the work it takes to reel the silk, it may well be that weaving simply isn’t the best use of those magical qualities, at least on the equipment i have available.

3D modelling

been wrestling with a rhino the past week or so. in theory i’m not asking it to do anything difficult, but in practice i just don’t speak rhino 😀

i wanted to make use of the benefits of digital design to make a medal for the bams student medal competition. i figured it would be a good way to split a shape with interesting geometry, and to produce two perfectly fitting halves of a whole.

initially i had no plans to use digital print in the final piece, i thought i’d just use it to produce a blank for mould-making, but when i saw the results from the powder bed printer i really liked the look and feel of them. it would also save all the additional work of mould making for traditional casting. i hoped by digitally printing i’d be able to include more detail than i could have achieved using casting methods, which still baffle me.

my tasks were splitting a solid, engraving text around the edge and inside, placing an accurate centre hole and applying an image to the top surface. mostly achieved in the end by flow along curve and surface and boolean split/difference to make cuts/holes in the solid.

the image on top is taken from a photograph (via photoshop) and used to create a heighfield surface – lighter areas produce high relief, darker parts are set back. i’m stuck at this point with how to join the height field surface to the solid medal, or even if i need to do that – if it renders okay it might print okay? only one way to find out… test printing… hours of test printing…

image on top is of a silk moth, bombyx mori. text is from kafka’s metamorphosis “he is my unfortunate son! can’t you understand i have to see him?”. the plan is  to cast the plainer bottom half of the medal in clear resin, including spun/woven reeled silk threads and a silk worm from inside a cocoon.

the halves will be held together using 4mm neodymium magnets in the central holes. it was brilliant trying the magnets in my first test print, they really brought it to life, gave it the pull of an  invisible thread that i was hoping for.

loom working

combs are taped either side of a wooden box. threads run around comb teeth and through alternate slots/holes in the reed. it’s an economic design for small amounts of yarn because there’s no waste warp. bunches of threads are tied behind the comb and taped in place.

i need a smaller shuttle for weaving silk threads because i’ll only warp the central section of the loom (i need small pieces from a limited amount of thread) and the long shuttle is a bit awkward to use on such a small loom. laser cutting one would be best as it leaves nicely smooth edges and anything even slightly rough that catches on the silk will be a problem. i need to sand the edges of the box for the same reason.

it’s a perfectly serviceable loom, not easy to work but i did manage to find some rhythm, which helped the selvedges. managed a full width/length sample in a weekend. i think with enough time and care it should be able to cope with the silk.