I did a topic quite similar to this a few years back – My study was on the socio-economic impact of these new technologies and techniques on the design industry, specifically looking at model makers. I had a few preconceptions that the new RP technologies would make traditional model making obsolete, that there would be reduced need for traditional techniques, hand crafted models/prototypes and subsequently jobs. What I discovered was a long way from that. I think the key point (as some have already stated on this topic) is that new RP technologies should be seen as new tools in a pretty extensive arsenal available to a designer. All these tools from sketching, marker rendering, sketch modeling, detailed CAD design, 3D rendering, rapid prototyping – the list goes on – all have different pros and cons. Good and experienced designers will be able to make the distinction and use the most appropriate tool for the task in hand.
To answer some of your questions more directly;
There is constant discussion about whether CAD has replaced sketching, but has rapid prototyping replaced the traditional skill of model making? & Has rapid prototyping changed your creative process as a designer?
I don’t think CAD has replaced sketching, I think it has augmented it. There are different things you can get from each technique – Sketching can be fast and allow you to quickly explore different forms, shapes and graphics. CAD can give you improved productivity in checking component package space – layouts etc. CAD and Sketch can produce visuals of your product – they may be of the same part but can be appropriate for different situations. For example we often produce glossy visuals of perfectly rendered products from CAD, these look great but when we’re talking and presenting to clients it can be often met with underwhelming response. We’ve found that introducing the sketch work, allowing the client see the story; see the creation of the product allows them to better understand the end glossy visual.
I think similarities can be drawn with traditional model making and RP. It’s about what best suits your situation. It follows that you need detailed CAD surface models to create RPs. For the early design process we will often sketch model alongside sketch development to understand the form – I find this makes CAD work so much easier, I find there is a fluidity to foam modeling that allows us to create surfaces and forms with out the concern of how to model it – yet. I find a sketch model can help the CAD process – I can visualise where to create splines and curves to create my surfaces. Beyond that we very rarely (if at all) create visual representation models without CAD. Typically in the development process we will 3D rout prolab or machinelab to create block models. This is often fairly inexpensive and allows us to finish our surfaces to accurately evaluate the 3D form. The machine or prolab is easily workable so we can make changes or quickly machine additional variations. (Often at this stage there is no detailed internal structure)
RP (SLS, SLA) costing is typically calculated by material volume cost, overall package size and a few other factors. The early RP’s we create are shelled surfaces with few internal surfaces normally from SLS. Further SLS models are then created with more and more detailing.
What does it allow you to do differently now?
For a recent project we had a suite of silicone tools made for a product. The detailed CAD work was done and an SLA master was made. The SLA master was then assembled with all the components, and a full fitting check was carried out – to catch any mistakes. The SLA master parts were then carefully hand finished (rubbed down, painted, lacquered and artificially grained) there is a great deal of skill in this process. The masters were then vacuum cast in silicone. We ended up with 30 fully working and visually representative prototypes. This entire process happened in about 3 weeks and the RP component of this was about 5-6 days.
Do you just use it as a tool to show clients?
No. Although these parts are used extensively in client meetings and design reviews throughout the process their use is not exclusively for presentation. For example the final prototype parts were cast in PU which allowed us to test the products quite extensively. We impact tested; high and low temperature operation testing; vibration tested and tested the product with focus groups to iron out bugs etc.
Is it just a safety net so parts can be checked and tested before they go into full production?
Not exclusively no although this is an important factor of the rapid prototyping. It is certainly more cost and time effective to capture any necessary design changes at a prototype stage than to have to modify tools etc.
I would say this is an area where I have seen big gains in RP over the last few years. There has been a steady stream of innovations in new materials available for the SLS, SLA processes (and that’s by no way exhaustive!) you can now sinter metals to simulate cast parts. There are processes that can give a chrome effect, or the materials can be coloured. RP materials can have mechanical properties that are similar to an injection moulded plastic which in turn allows a designer to gain greater insight into the performance of their design. At the same time RP is becoming more and more cost effective. I can have a complex geometry part (say 200 x 100 x 50 mm package size) rapid prototyped in a standard SLS material on my desk within 4 days for around £200. That’s pretty good and we find ourselves using the process more and more increasingly in place of the 3D routing or machining.
Have you ever used it to do low-cost low-batch products as a result of these technologies?
Only for batch prototypes so far.
Good luck with the dissertation,
Boz
to have seen the increased popularity of rapid prototying over recent years.