Computer Control for primary Schools

Recently advised a Primary School on what control equipment to buy to introduce the topic to staff and pupils. Went through 4 systems, starting with simple circuit boards you set up a sequence of commands with for about £6 each, through to specific education systems costing about £120. At the end, the head asked me..yes.. but whats the best system? I advised her it was 'LEGO NXT' and she promptly bought 5 kits. I hadn't included this in my list of 4 initially because of cost, but i think she chose wisely!

This may be a suprising choice for many schools, and certainly is not the cheapest option, being around £1000 for 5 kits and a site license for the essential NXT Mindstorms software, but it has many advantages. The pupils are not scared of breaking it, they are already skilled in assembling the components, the leads used are robust and cheaply replaced if they do break. Replacement parts are all numbered and cheap to buy, and finally, it is compatible with every other LEGO brick in the world.

Of course there are a a few downsides... 471 pieces, many tiny, is a big classroom managements headache so I suggested they bought some rather oversized rolling toolboxes big enoughto store all the bits, and with room for part built models in the base.

My favouite piece of techhie kit for school is the Roamer, a simple big disc shaped thing with buttons on. Someone very clever decided it should be powered by those huge square lantern batteries and therefore it went for ages and could be stored ina cupboard without losing charge... You can still buy them..but I would now buy NXT!

Short Change

I wrote a set of Structures worksheets for a DT department a few years ago that needed to be taught by all staff, regardless of technical ability in structures.

The sheets went through the basic types of structures and used only 'spills' the thin wooden sticks used to light Bunsen burners, and plasticine, along with a bit of paper and some wooden blocks for weights. It proved very successful but I noticed some of the kids did not use the materials in correct ways because the long sticks with their flat absorbent surfaces stuck to the plasticine so well that quite bizarre angles could be made, and the flat sticks could be stuck together along their length to make very rigid pieces.

In the last few weeks, I have developed a similar structures project using a set of 7 photocopied card project sheets onto which pupils build directly. I used plasticine again ( Actually 'modelling clay' as its much cheaper and the same stuff!) but this time used cocktail sticks which I bought very cheaply from www.rapidonline.com. The shorter sticks have a round cross section and are non-absorbent which means pupils ideas need building more carefully with proper triangulation if they are to be weight supporting structures.

The idea still needs refining, but I only asked for self-supporting structures, and in hindsight, they should have been load bearing ones. Often picking something common but tricky to hold works well, such as a packet of skittles sweets.

Gearbox Grindings

I have developed this gearbox for a client who is working in partnership with a power generation company and wishes to promote renewable energy information.

The gearbox uses extremely cheap PVC gears available from http://www.rapidonline.com/ and http://www.mutr.co.uk/ which come as a set of three gears to push fit onto a 3mm shaft and a pinion gear to push fit onto a standard 2mm electric motor shaft. I came up with the idea because the gearboxes already available needed a lot of parts and used fairly small gears, and cost a lot. As regular readers will know, bringing costs down to schools is essential as then projects can be individual or small group and be integreated into the regular SOW of a school.

The front and back plates are manufactured on a laser, but can also be made on a router using a 2mm cutter. The bolts holding it together are standard M4 ones, and the motor used as a power generator is a standard large size solar motor (http://www.mutr.co.uk/) .

It can be built with three combinations of gears giving ratios between 1:3 and 1:14 approx. These arc easily changed in about 3 minutes.

The total cost in parts to a school is about £2 and having fairly chunky gears with big teeth, it is robust. The longer plate, on the production version, is designed to be cut in 3mm plywood so that the gearbox can be screwed to a pole and then stuck in the ground for testing.

The client and I will be offering this design to a manufacturer to produce a kit in bulk. It is hoped that many schools can then benefit from this project.

Decent Coffee!

Since going full time as a consultant this January, I have worked in a lot of Cafe's and drunk a lot of coffee! This is because much of my development is better done in environments which are stimulating, so there is the table by the lake in Nottingham University, the Garden centre near Wollaton and the non-smoking pub which has free wireless access. Sitting in a box produces boxy ideas... Of course, lugging a 5kg laptop and bag around means I do not have a lot of license to wander around while set-up... so hence my new interest in Expresso. Proper Espresso, as described to me in a book by a fanatical chef, is tiny, not bitter, and has a 'crema', the bit that's a little frothy on top, that supports a teaspoon of sugar for up to 10 seconds.

Temperature, water, cleanliness of the cup, pressure, type and amount of Coffee and the amount it is 'tamped' before being put in one of those gargantuan machines are all critical.

It also means you don't have to nip to the loo all the time to eject excess fluids, leaving your laptop behind!

So why talk about Coffee on a Technology Blog? Because many of the stages in making a decent cup of coffee are ideal for a cross curricular project... Maths does the costings, ICT records temperature and pressure, Science collates, DT produces the perfect measure and 'tamperer'.
Even better, it is a project with an easily assessed outcome, using relatively cheap ingredients which almost anybody can give a qualitative and quantitative judgement on.... I also think the various Coffee companies littering the high street would jump, if properly presented' at the chance to do such a project and reap the substantial PR!

And finally, think how much livelier the staff room would be with all those free espresso samples available!

Laser Cutting

This little device was an idea I had a few years ago when first getting access to the type of small scale laser now common in secondary schools.

I developed this prototype over many hours and the final CAD file took about 12 minutes to cut on a 40w laser in 3mm plywood.

When I contacted companies to make it in bulk, I quickly discovered why making things in wood was rare today. Unless I had special patterns made in China to stamp out the pieces, and it wasn't certain such fine detail would be reproduced using this method, it would have to be cut out on industrial lasers in this country. It worked out about £12 a set of pieces cut which gave a final selling price in the shops of around £47 by the time other costs and the shops markup + VAT was added.

The sad thing is, I could have all the pieces made as plastic injection moulded parts for £1 (Flat plate mouldings) if I committed to buying 10,000 sets. This would give a final selling price in my targetted shops of about £7 which was acceptable. Of course, then it would be in plastic instead! We will rely less on plastic when it is either too expensive, or there are good industrial techniques and materials to replace it. I suspect we will reach that point in about 20 years.

If you do some research, you will find the most popular early plastic was Bakelite... And that was mostly sawdust! Of course, the second most popular..and available thousands of years before Bakelite..was tortoise shell!

Anyone want to try something new?

For the past 3 months I have sweated over a set of 4 schemes of work (units) for the University of the First Age, that teachers can take and use to run courses with children, and they are finally finished.

There are four. Pow-Zap, about using super capacitors.
Kinetic, about building large water powered sculptures.
NXT-H20, about solving a design problem using the LEGO NXT system.
2-Take, designing and prototyping an alternative bicycle load carrier.

If you contact the UFA, they should be able to give you more details about the units, and you might like to try running them yourself. The units contain a full SOW, technical details, online bookmarks, oodles of 3D models and 2D sketches, as well as powerpoint introductions and worksheets where required. The Schemes of Work alone run to about 36 pages so there's plenty of material to guide you!

TINY PICAXE DICE - MODULAR

The dice shown here is part of a set of 5 PCB's I developed in 2006 for a client. These haven't been tested yet so I am not sure if they will work as the client was intending to get pupils to trouble shoot them before a final version. They were created in 'Real PCB', a package I have used and up to now has been pretty similar to the other main educational PCB design package, 'PCB Wizard'.

I think I should express an interest in PCB 'Wizard' and its excellent successor, Circuit Wizard. I did some paid work for the company who makes the programs, but was hired after I was already using it with GCSE and KS3 pupils because of its excellence.

So why the dice picture? Firstly, I love to see how tiny I can make PCB's which are still usable / editable by pupils, and that are easily made as single sided boards. This one is about 45mm x 35mm if you stack the boards. With a little ingenuity, it should be possible to use a tiny 6 or 12v car alarm battery to power it and squeeze the whole onto the PICAXE PCB. I believe that with sample projects such as this that pupils learn on / with, it is important that you can see where the tracks go and understand how it works.

Secondly, It is part of a system where the base 8 pin PICAXE board acts as the starter for pupil projects, and they design the add-on bit. This may seem less satisfactory than designing the whole thing on one board, but as PICAXE 'headers' are part of all common PCB design packages, making it a discrete board seemed neater. It also means pupils are designing just the interface / outcome, not grappling with the whole board. Such an approach can give rise to track routing problems but there is no reason why connections on the pupil board could not be spaced around it rather than lined up in a row.

Thirdly, To tell you that there is a new version of Circuit Wizard due imminently. this will integrate together Circuit diagram, PCB layout and PICAXE programming into one interface. Then I will not have to wait for someone to test the idea above by building it. Instead it will be fully tested from within a single program. If it was available now, this article would be posted on my main website rather than here as a concept item!

I think that electronics has been the area of DT that has seen the biggest changes in the last 5 years. It is now extremely close to industrial methods of designing / testing and manufacturing one-off / prototype devices. Perhaps with the advent of such sophisticated technologies in schools, we should re-examine exactly which GCSE pupils should study. I was required to change to Product Design a few years ago from Electronics but still teach a mainly electronics based content. It wasn't a brilliant fit of subject and syllabus at the time, but it may prove ideal with such powerful software becoming mainstream.