Freesteel Blog » 2007 » February

Tuesday, February 27th, 2007 at 3:24 pm - - Whipping

I must have been wondering about how we conspire to get ourselves ripped off, and began thinking about this new Creative Writing course at Manchester University, where the majority of the money is most likely to have gone into hiring the name of Martin Amis. As a result, I wasted most of the morning documenting the fact that he is a raving Neocon who condemns all of Islam of being suicide bombers, based on the his interpretation of the facial expression of the gatekeeper at the Dome of the Rock in Jerusalem after he was calendrically rude to him.

I am interested in the subject because I was at a long-established SF writing course in Michigan in the summer of 2002 at the time I was sold out by my previous employer. And so began my adventures.

The course I went to was enormous fun. It is in no way associated to the corrupting influence of the mainstream fiction industry with its elite in-crowd and the use of name associations to open doors to the mainstream publishing world, where the game is to get powerful people who make corporate decisions that pay-to-play to put feeble books on the front table in Dillons, where it consequently determines what sells and who gets to make a career out of it. All human weaknesses are for sale.

While at my course in 2002, I wrote an interesting short story called Mine the Primes, which to me justified the full expense.

Meanwhile, in the real world, the rot in the fiction industry occurs at every single level, from the grooming of new young authors, to the resulting mass-produced mentally impoverished over-blown literature that most people read. Never ever trust a book review by one contemporary writer of another contemporary writer; they are colleagues; they are all in the business together, unless there’s a falling out of one of them, usually as a result of accidentally telling the truth about another of their number. The dire quality of the fiction which the public reads stupifies us and makes us vulnerable government propaganda which, in my view, is in a class of its own within the genre of Science Fiction. Ballistic Missile Shield, my arse!

So, what’s the problem with a writing course over in Manchester hiring a leading author like Martin Amis to teach their students, then?

The problem is he ain’t there to teach the students. He’s expected to be on a virtual permanent sabbatical, trading on the job title as “Professor”, while they trade on his name at the head of their department to sign up students at exorbitant fees. You go to University only once, so you can only get ripped off once, after which you learn that before you handed over your money you should have asked the question:

You know that famous author that’s attracted me here to this esteemed course? How many days will he actually be teaching me this year?

If the answer is just two weeks between all the students, since all the work and marking is due to be handled by the remaining overworked and underpaid staff, then it doesn’t look good. All staff should do the equal amount of work, with no Prima Donnas, otherwise it’s just not going to be happy. Don’t go there.

I checked my opinion with someone who used to work in UEA, where there is the rival creative writing course that this new business is modeled on, and was told that I just didn’t understand how the world works. It’s quite reasonable for students to be attracted by the name at the head of the department, because they would get something out of it, even if they never actually got taught by the guy. Once they have graduated, they can use their association with his name to open doors in the publishing world. In fact, he is likely to give that essential help to them in the form of the opportunity to have their work brought to the attention of agents and editors by him; editors and agents too lazy to look for talent outside the immediate sphere of paying customers of the most overpaid and militaristic religio-racist writer in the country, and so excluding people who have enough common sense to spot a rotten waste of an educational opportunity, or can’t face buying into the culture.

I’m just too idealistic, which is why I don’t get anywhere, I’m told. No one who gets through this writing course is going to say anything bad about it, or reveal how little actual contact they had with Martin Amis during it, because they will want to trade on the reputation. They will not want to debase their investment.


Prospective students don’t have the experience which would make them wise enough to see through the marketing from the University before they buy the course. Once they have bought the course and put it on their CV, they gain a conflict of interest that has the effect of preventing them from passing on their wisdom to the next generation of prospective students.

And so it goes on, like so many businesses that continue to persist in spite of contributing nothing to public good.

Of course, this whole cycle would collapse in an instant if the students in a particular year kicked up a fuss at the time. What could they achieve?

First of all, they must make direct personal contact with students who had been through the course the year before and share information and horror stories. Not all of these graduates would have made it yet, and their experience would be fresh. While being utterly powerless, their contribution would be essential to give a degree of certainty to what this business is all about. You can never be sure you are going to be ripped off until it is too late.

And secondly, they have to unite and organize around their demands. Here’s what they could demand: Martin Amis in Manchester teaching and marking their fiction five days a week for two terms. Hours worked should be proportional to pay for all staff. They should demand that the full accounts, contracts, timetable, and pay scale of the course supervisors be published on the Centre for New Writing webpage. People have a right to be told what they are buying, and if the powers that be think it should be confidential, then what they are really telling you is they’re ashamed of it. Complain effectively and you can get a good deal.

What power do the students have? If they united and managed themselves well enough, using their supposed skills of writing and imagination, they can wield some seriously bad publicity. The whole edifice exists on reputation, with very little substance underneath. They can, if they choose, make the whole business an unmitigated disaster. They could permanently tarnish the name of “Britain’s greatest living author”, and send a message of humiliation into the closed world of British literary establishment.

In the process, they would wreck any chance of a career along the current conventional safe ineffective boring route into the dead literary establishment, but they would gain notoriety and breath life into things. What better way to make an impact and make your name? These courses ought to be a hotbed of literary trouble-making for their own ends.

Never mind. It’s not going to happen. Our generation has been so ill served by the state of fiction today because of the way it provides a benchmark to the imagination. It has stupefies us in our jobs, running a futile rat race under corporate rules in the protection of a military complex that just keeps on killing.

We can’t imagine that the world could ever be a better place, so we don’t notice that it is being actively kept this way by the privileged in any profession.

Sunday, February 18th, 2007 at 2:18 am - - Weekends 4 Comments »

I’ve suddenly wound up in Cambridge for two weeks to keep house for my grandfather as he gets radiotherapy treatment at the large hospital on the other side of town. They send a taxi over every day. If I’m lucky there might be room for me to go in it.

I’ve got limited internet connection here, which is a good thing because I’ll be able to get through to the end of all this drop cutter coding without too much distraction.

I spent all of Thursday ranting about UN documents to an unlucky visitor to Liverpool who probably didn’t know what hit him. Then I went to Manchester to experience the misery of cycling down Oxford Street in the rain, leapfrogging the double-decker busses until I gave up and went on the pavement, before dropping off Becka’s passport at the Chinese consul and getting a blood test on the way back.

Then I had two hours programming the ball-nosed cutter case before going to a public lecture by some nutty particle physicist called Martinus Veltman who believes that the general theory of relativity and our understanding is gravity is all wrong.

He made a reasonable case, beginning with the fact that astrophysicists are full of crap, what with their going on about reading the handwriting of god. Nothing that they’re doing goes anywhere close to the real mystery of life, which is: How do our brains think? Also, they don’t do any experiments, so they can say whatever they like about the existance of a black hole at a certain place in space, and no one can prove them right or wrong.

Particle physicists, on the other hand, do experiments. For many decades they have been having to invent numerous new nuclear forces to explain what they are seeing. These new forces all start out as fudge factors, from which they make predictions that they then test on a particle accelerator. The latest and greatest fudge factor is the Higgs field, against which they’ve bet three billion Swiss francs on building the Large Hadron Collider. Either they’ll see direct evidence of it this year, or they won’t. Nobody really knows. That’s what really makes it interesting.

Meanwhile the cosmologists, who are able to make pretty photographs through their telescopes, have their own fudge factor known as Dark Matter on account of the fact that nobody has ever seen it. It’s only there, according to them, because they believe that even at the super large scales of a galaxy, that familiar law known as gravity must explain everything.

Why should it?

The subatomic physicists have had to invent the strong force, the weak force, the Higgs force, spin, quark, strangeness, and charm; so should we be surprised if the same nonsense of new laws unobservable on a human scale need to be postulated at large scales beyond the level of the solar system?

Of course not. There’s the Pioneer anomaly and the flyby anomaly where man-made objects in space don’t quite go where they ought to. I don’t know what’s special about them, except they have transmitters and we know how heavy they are because we put them there, so we’re not deducing an equally anomalous mass from an anomalous motion in such a way that we don’t notice it.

But worse is the galaxy winding problem where, if gravity was all that’s involved, there would never be any spiral arms because they would rapidly be smoothed into an disk, like the trail of cream on the surface of a stirred cup of coffee. The stars near the centre should go round faster and leave the far tips of the arms many revolutions behind. But because the cosmologists observe that the whole galaxy seems spins as one, they need to invent a huge halo of invisible “dark” matter around the outside to make it so.

This is real science: a model which produces predictions that don’t match observations without faking it, and suggests that there is something big we don’t know. We need to deal with the data and invent new and interesting theories to explain it which, if we’re lucky, we can test with an experiment.

On the other hand, the science of climate change doesn’t have any mysteries left in it; at least not of the sort that makes it worth running this particular excess atmospheric CO2 experiment we are currently conducting on ourselves, because we already know the answer and are not going to like it. Nevertheless, we still pay our politicians to lie about the facts, and put our minds at rest with the proposal that we had managed to weather a similar scare story in the past about global cooling that so convinced the scientific establishment it amounted to two whole articles in Newsweek in 1978.

I’m lucky to have been allotted a life span that fits into the most perfect time slot that a human being could ask for. Presently, medical science is good enough to avoid needless suffering, and we have the internet, and I will be able to watch the world through the most amazing period of transition with a mind is just mature enough to really appreciate it, without being too old and bitter. If I live to be as old as my grandfather, that’ll take me to around 2060, which is not many years short of when our life supporting environment is scheduled to really go tits up.

Of course, I could die young if I don’t stop staying up so late after my bed time. Night night.

Wednesday, February 14th, 2007 at 11:36 am - - Machining 9 Comments »

Well, that’s about seven hours work. I can’t operate these newfangled graphics editors (which anyway don’t have the offset ellipse as one of their types), and have resorted to writing a python program to output the raw SVG file, which you are now previewing.

I did this to make the diagram for my previous posting on the offset ellipse, but then lost the program. This time I’ve taken the precaution of copying the code into some sort of a commented

<![CDATA[ **stuff goes here** ]]>

section so I can only lose it if I lose the diagram.

Not sure this diagram is all that comprehensible, but a is the shaft radius, t is the torus radius of the tip, t – f is the corner radius. The conical section of the tool connects tangentially to the torus tip at the radius c. If we let h be the height of the torus — the vertical distance between the c line and lower a line — then I reckon:

(a – c) / h = tan(taper_angle)

There are four distinct surfaces and one touchable edge on this toolshape. The other two edges have tangential surfaces on either side, so it’s not possible for them to touch the model.

The model is made up of triangles, which themselves are points, edges, and facets. I think I’ve been through all this before. Before lunchtime I’d like to work out the contact point between an edge and the conical surface.

I don’t know whether it’s better to put everything on one diagram, or make a series of diagrams showing the different toolshapes, for example taperless, or ballnosed. Once I get something that’s good I’ll upload it onto wikipedia, which has a great SVG engine, and stick it in one of their articles.

So here’s a question: can anyone work out what the little green dotted circle in the middle is supposed to represent?

Tuesday, February 13th, 2007 at 7:58 pm - - Machining 3 Comments »

Now the drop cutter function is enabled to handle horizontal edges as well as vertices of the surface. It’s the trivial case, because you take the closest point in the edge to the cutter centre and send that to the drop cutter on vertex routine.

Most of the day was spent getting rid of the glitch I’d found in the const scallop algorithm. I feel it’s becoming more and more stable all the time. I used to spend many man months on the const scallop (aka const stepover) algorithm in my old job, and am determined not to get it wrong this time. Getting it wrong means you have to give up and write a filter that simply deletes all the spikes and glitches that the toolpath algorithm has mistakenly produced that you are unable to solve.

This is a common hidden factor in CAM software — the cleaning up of the toolpaths before the user gets to see them. Once such a module is installed, the underlying algorithm can really fall apart, because the programmers never get to hear of its failures any more.

It’s a common pattern. Suppose you have a machine M making widgets that occasionally makes a bad part because it’s a bit worn out. There’s trouble if you let one of these bad parts out of the factory and into a customer’s hands. Now, you can either choose to fix machine M so it stops making bad parts, or you can build a second machine Q which examins the parts coming from machine M and discards those which are bad.

This is a good solution if fixing machine M is a really difficult thing to do, and the proposed machine Q is a reasonably simple device. As long as the bucket of bad parts which Q throws out is not too full at the end of the day, you’re well ahead. When the bucket starts to overflow all over the floor, you can tell it is time to go and fix machine M.

Unfortunately, if machines M and Q are parts of a system of software which you are selling as a unit to a customer to make their own parts, it’s easy to lose track just how many bad parts machine M is making. The bucket of bad parts is virtual, invisible to the user, and not accessible to the programmers because it is now off-site.

These Q-type modules are one of the first things I would look for in a CAM system that has made its source available to me. I’d want to know how long has it been in place, is there a way for information on the failures in the hidden algorithm M to get back to the programmers, and what does it look like if I disable it.

This can’t be the first time this observation has been made. I’ve searched on the phrase “silent quality control” and “silent error detection” and came up with virtually nothing.

Whatever it’s called, you don’t put it in if you think you’ll be the person who has to debug the code in ten years time, even if it slows things up at the beginning.

Tuesday, February 13th, 2007 at 11:25 am - - Machining 2 Comments »

Beginning with the easiest, I’ve done cutter location against a set of points picked from a model. I’ve learnt my lesson and done it for the uncommon tapered cutters from the start, rather than going for the easier cylindrical type of cutter, and then having to fit this feature into the code later.

I’m also short of simple machining algorithms to test it on, so this is what it looks like when used by the const scallop routine. The complex shape of the toolsurface gives the algorithm such a good work-out it’s exposed a couple of glitches which I am determined to deal with before I carry on. Unfortunately it requires running in debug mode, which is rather slow. I need patience.

Monday, February 12th, 2007 at 3:06 pm - - Machining 1 Comment »

I’ve got quite a few distractions this week, so it’s not realistic that I will be able to completely rewrite the cutter location code by Friday to be fast, but I’ll have a go. I started working on it last night and have the initial interface of it sorted out.

The main innovation is that, rather than building a machining strategy object (eg pencil milling), and posting a surface to it, followed by posting a set of parameters to define a cutter shape, I’m going to have an intermediate object called ToolSurface which takes just the triangulated surface and the tool shape. And then that is going to be added to the pencil milling object, followed by the other parameters that it requires (eg bitangency angle).

This is an interesting change in structure because it gets round the fact that these algorithms don’t want to have anything to do with the surfaces; they only want to know where to put the tool. This is a really obvious modularization I haven’t done before.

Most of the speed is going to come from optimizing the boxing (bucketing) of the triangles in the most efficient way for the given toolshape. The speed comes from scanning as few triangles as possible.

There are several files of Danish code doing this precise algorithm which we have been relying on so far. However, after looking at it long and hard, I can’t see how to salvage anything from it. It’s full of all kinds of arrays of function pointers and is truly unnecessarily complex. It doesn’t matter for them. According to the scientists, the Danes are the happiest people in Europe by far, and no one can work out why.

Monday, February 12th, 2007 at 11:55 am - - Cave, Whipping

Down in Cambridge for about three days. Spent one day offloading a pile of my public domain offset ellipse cutting code on a company I ought to be able to name. We’ll see what comes of it. In the process, I’ve worked out the perfect diagram to explain the whole of the geometry of the torus touching a line. It’ll take a while to draw, as these things do. A picture is worth a thousand words because it takes a thousand lines of code to plot it.

Then I was with Francis in his house with Tom from mySociety as they battled with this goddamn Road tax petition that seems to have been the only internet phenomenon we’ve sparked off so far. Bum. What the hell is it with British people and their cars? You can tap their phones, monitor their bank accounts, CCTV their movements on the streets, but the moment you threaten to surveil their cars — wham!


Tuesday, February 6th, 2007 at 9:43 am - - Cave, Whipping

Just getting ready to head down to Birmingham this morning. Someone has invited me to be part of an advisory board of the National Open Centre, which will be some kind of official point of contact for Open Source things for the government. This doesn’t mean that it itself makes any contact with the open source movement, but maybe it will try. With routine government sell-outs of IT projects for billions of quid to corporations who are therefore extremely successful and profitable, in spite of writing software worse than a dog, something must be done.

At the very least one can move that, as in America, any software that is fully funded by taxpayers must be open source. Then we could (a) look at the quality of the stuff these corporations are producing, rather than the quality of their balance sheet, and (b) the project could easily be taken over without the necessity of throwing everything away and starting again, which tempts one to keep throwing good money after bad.

After all, if you’ve thrown out the dodgy builders, you at least get to salvage the bricks which you have already paid for.