Frequently Asked Questions

Why is Design for Manufacturing important?

Design for ManufactureDesign for manufacture (DFM) is incredibly important (even in additive manufacturing!) It’s all about taking full advantage of the selected manufacturing process whilst at the same time engineering the part(s) to suit the process and minimise cost.

As the manufacturing method is frequently undecided when a client initially approaches us, support to make the necessary changes becomes an important part of the design service we supply.

It is important to note here, that despite the media storm that has over recent years given the impression that additive manufacture is the ‘cure all’ process, the additive processes are still bound by a set of design rules in very much the same way that ‘conventional’ manufacture is, they are just different rules!

Understanding these rules, or designing for manufacture, is as important today as it has always been. Ignore the rules and you will get a substandard product, or at best you will pay over the odds for something that could be produced for less.

What is design for manufacture?

So design for manufacture is just that. It’s designing with a manufacturing methodology in mind, such that features are created in ways the process can replicate without difficulty, as difficulty usually means additional cost!

Potential issues can range from a simple chamfer around a hole that requires an extra setup when CNC Machining; to more complicated issues such as the way in which a hole is created during injection moulding that may require an additional side action, or how to anchor a boss to a thin wall without compromising the tooling or creating sink marks on an aesthetic surface.Optimisation

How do we select a manufacturing process?

So how should a process be selected? There are several important factors; probably one of the most significant is the quantity of parts required. Then there is material, size and complexity of part, and what kind of aesthetic finish is required. 

The problem that frequently occurs is that quantities, especially in the launch phase are not known. So whilst the expectation might be 5 – 10,000 per year, the first batch might be just 50 off. The natural desire is then to try and postpone any capital expenditure on tooling until quantities begin to rise. This can lead to different technologies being used initially that are not optimal for the design.

There are ways of doing this, but frequently they will require small modifications to the design to improve the economics or sometimes to make it a feasible proposition at all. 

What if we need to prototype and yet will want to injection mould eventually?

This is where we can help, as not only do we distort the conventional quantity/process relationships, but we also specialise in adapting designs to suit the required process. Note, if that process is injection moulding, then we have developed four categories of tooling, to suit different phases in the development programme, which is another article in itself - you may be suprised at some of the options!Injection moulding

The good news is that Plunkett Associates have access to a huge variety of processes, which gives us incredible latitude to find the optimum solution for a project and ensure the design is suitable. 

Having said that, acknowledge that manufacturing may require some modifications and so we cannot emphasise strongly enough how early communication is important. Perfecting a design before opening discussions can quickly unravel days of work - so talk to us now!

Bottom line; whether the production method is additive or subtractive, prototype or volume, talk with us to understand your options. Then we can work with you to create a design that meets your requirements, yet is straightforward to manufacture. After all, that is what Design for Manufacture is all about.

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