RE: RP for Rapid Manufacturing vs. Hybrid approach

From: Prof. P. M. Dickens (
Date: Sat Aug 07 1999 - 01:36:11 EEST

Please find comments below:

> Surely the future for RP is to work towards "instant tooling" which is
fast and cheap
> enough to negate many of the problems associated with production tooling

This may well be the case for many situations especially when you want lots
of the same part. However, we need to remember the limitations of the
different Rapid Tooling processes in terms of durability and also the
different mechanical properties of the mouldings due to different cooling
rates than in metal tools.
Also I would argue that tooling is the last thing industry needs! If a
manufacturing process needs a specific tool to make a product then it has
instantly become inflexible. The design becomes locked whether it is good or
not and there is resistance to change because of cost, risk or lost
I am not saying that we will use RP to make everything. We will still need
conventional processes and tooling where numbers are high or where we cannot
get what we want with an RP type process.

> I concede that (for instance) an SLA 7000 building trays full of
> widgets can outstrip conventional injection moulding on cost
> (initially anyway) - it will be interesting to see your new
> figures when they are available - but how many widgets have you
> seen recently that are made from UV resin? Just look at the
> mechanical performance differences between a prototype part that
> is machined from solid thermoplastic vs. the same form but
> moulded condition. OK, so in some circumstances a high grade SLA
> material may suffice, but I would argue that, even for complex
> parts, building ONE high res. RP master to make ONE (fast, low
> cost) rapid tool is a more efficient route.

In the end it all comes down to money. If an RP type process can make what
you want at a lower cost then use it if not use another process.
We also need to not get trapped into present thinking. There is a variety of
RP processes now producing parts in a variety of materials. We have only
just started along this route and I am sure we will see more processes and
many more materials in the coming years.

> I would be very interested to work with you to provide proof of
> the above statements for a range of different part sizes,
> geometries, etc. Please let me know if you have any interest in
> this offer.

I am not sure that concentrating on direct cost comparisons for existing
designs is the best thing to do (although we will need to do some of this).
Lets make use of the advantages of the RP type processes and free up the
designers and the manufacturing organisation.

We will re run the three parts on the Flymo study and check the new numbers.
When we have done this I would be very grateful if you could make a tool
with your process and we can do a straight forward break even analysis.

Many thanks


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