Posts Tagged ‘Not invented here’

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Horses for courses don’t invent wheels

September 26, 2009

The phrase ‘let’s not re-invent the wheel’ is often applied when looking at a new problem, and tells us that we should not work out a solution in isolation but look around for existing similar work. However it’s also often misapplied to building the solution, that is: when a wheel needs to be built, we should use an existing one. 

This is a Bad Thing. Wheels may come with the same side-on shape (generally round), but they come in many sizes and weights and widths and treads and load capacities and power hookups. 

Some wheels only look like other wheels at first glance. A motorcycle wheel for example, is about the same size as a car wheel, and it has a tyre and everything. But there are a variety of power deliveries (via chain or belt or direct shaft), none of which are compatible with modern cars, and the build is lighter and weaker, and the tyres have a different cross section that is vital for going around corners. 

Horses for courses

A wheel built a hundred years ago for a cart, with a hard rim and hand-greased rolling surfaces, would last a very very short time on a modern car before bursting into flames or fracturing into a fast flying cloud of sharp and pointy shards. 

Wooden wheels on a hummer

Although you can always count on someone, somewhere, to make it work

 

It would take quite a bit of work to fit a modern car wheel to a pedal bicycle, what with altering the frame to fit and adapting it to take the chain. And it would be heavy to move and awkward to steer and nearly impossible to repair by the side of the cyclepath. 

Attaching a bicycle wheel to each leg of my chair would certainly up the speed at which I zoom up and down the office cubical aisles, but the stability of my chair, its ergonomics and my typing rate are all also likely to interfere with my productivity. And health and safety might want a word. 

Building our own wheel

When it comes to a specific application – a wheeled horse for a hard-surfaced course perhaps – we should indeed look around and see what other wheels exist and the various wheel building techniques. 

May be there is one we can buy off the shelf that will work just as we like, but even so we will have to learn enough about wheels to properly evaluate these shelved ones against our requirements. And we need to ensure that the wheel can actually be supplied in time, that instructions for its installation and maintenance are understood, and that parts will be available as appropriate. 

If there does not appear to be an exact fit, we may be able to modify an existing wheel. This too means understanding not only general things about wheels, and establishing the same assurances of documentation and supply, but some very specific ones about that specific one; will the material take a weld for the hoofals? If we bore holes to take bolts what change will it make to the structural strength? What help will we get in doing this – if any? 

Where we want more control over the build our wheel, we can still re-use other components. We can build our wheel so it takes one of the standard motorcycle tyres for example, so that the horse can corner properly. 

And in any case, we can use modern tools – such as plasma laser lathes – that make the build time for specialised components very short and the quality very high, even where we are building our own specialised bespoke (heh) components. 

So, let’s not reinvent the wheel

When it comes to building a solution we need to establish and re-use skills and methods and tools. Even without re-inventing the wheel, we can and often should build our own wheel from various existing components where appropriate, but otherwise happily manufacture our own special components to create a wheel that will do the job.