RP – JIT

Citation

Loughlin, C. (2005), "RP – JIT", Assembly Automation, Vol. 25 No. 4. https://doi.org/10.1108/aa.2005.03325daa.001

RP – JIT

Rapid prototyping (RP) is a theme area we have covered regularly in the past, and while putting together this issue I have been struck by parallels with computer graphics. It is not that long ago that computer generated images were rather chunky and with a limited palette. However, these days they can produce images that are so lifelike you cannot tell the difference.

Three-dimensional CAD systems can now produce images that are so realistic, with lighting and surface reflections that they actually look better than the real thing and it almost seems a shame to return to reality and actual make something.

In this issue we will see examples of just how sophisticated RP technology has now become. A wide variety of technologies and building materials can now be employed ranging from plastics to tool steels and biocompatible materials. It is now even possible to produce coloured parts, with the result that it is now difficult to tell RP parts from their mass-produced equivalents. We are not quite there yet with surface finishes, but the days of the highly ridged translucent plastic prototypes are now over.

It seems to me that there are four main areas for further developments and these are surface finish, speed, materials and cost. Of these I would consider that the most significant for the extension of the application of RP technology is speed. It still routinely takes tens of hours to produce prototypes. If this could be reduced to a few minutes then we would all start using RP machines with the same regularity as we do our office inkjet printers.

Time costs money, and any process that takes tens of hours is going to be expensive. Even if the process itself is completely free, its slovenly behaviour will be costing its users money as people and other resources are left waiting for it to finish. Such delays could be argued to encourage people to take more care in design; however, it is also inevitable that delays will restrict the flow of creative ideas and will certainly reduce the number of iterations that a product design will be able to go through.

If something takes a few minutes and not too many dollars to make, then designers will be encouraged to experiment more and hopefully come up with more creative and better solutions for their companies.

When I first started using computers the golf-ball printers managed ten characters per noisy second and graphics were restricted to “-” and “^*”. They were also very expensive. These days office printers are virtually given away and the companies that produce them make their money from the inkjet or laser toner cartridges. They also churn out reams of paper at alarming speeds and with text and images of photographic quality.

I cannot envisage that RP machines will ever be free as they are more complex and will never be subject to such economies of scale. However, I can foresee that the companies that make them will get the prices right down and similarly make their well deserved fortunes from the exotic consumables.

If this could be achieved then conventional manufacturing might also be turned on its head. If an RP machine can make a part in 10min then ten machines will produce one a minute which equates to about 500 in a working day. At these sorts of rates they could accommodate a good percentage of manufacturing demands and provide the benefits of JIT delivery and reduced stockholding. They can also be switched instantly from making one product to something completely different and enable individual item customisation.

Clive Loughlin