Product Design vs Machine Tooling Design, What’s the Dif?

What are the two main differences between product design and machine tool design?

Right off the bat I think of two main differences between designing a product and designing machine tools.



Product Design Time

When designing a product there may be numerous design reviews, you may spend a whole year or longer between conception to tweaking the design, testing it for market appeal, functionality, safety, costs… the list can go on.  And many of these reviews don’t happen just once.

Then, when the product gets very close to completion, the manufacturing team starts planning for production.  What parts will be assembled at what stations.  And the Manufacturing Engineers and Managers start working on planning the design of the production machines.

Machine Tool Design Time


Once the product is getting close to release for production, there is a rush to get the machines, designed, built, and tested fast.  The time line for a Machine can be as little as 1 month.  Some of the more simple tools are created on the fly as the product moves into production and the need is discovered.


With Machine Tool Designs there may be only one or two design reviews.  There is no need to make it look nice for the consumer, though safety and functionality are part of the design and review process.  The whole machine design process doesn’t require as much time or as much… “going back to the drawing board”.  (For those of you who are too young to have ever seen a drawing board, what I mean is in my experience there isn’t as much re-design occuring in machine tool design as in product design.)


One thing I hear from those who move over to machine tool design from product design is that in machine design the available stock size matters.






With each new manufactured part you need to think about using nice numbers so that the part can be manufactured easily with the least number of surfaces having to be finished.

A machine tool designer is always looking up stock sizes.  And every time the designer has to change the size of a part they have to think about stock sizes and which surfaces will need to be finished.

When a machine designer can avoid finishing a surface, he/she saves build time and material, reducing the costs of the machine.  So we must always check our stock sizes, and try to make the mounting surfaces stock dimensions. This way we avoid having to machine a nice mounting surface if we don’t have to.

When a piece of metal is saw cut, the surface is very rough and may not be square to the other surfaces.  So mounting surfaces need to be stock or finished in most all applications.

Hot Rolled Steel is so rough even as stock, it needs to have all it’s mounting surfaces finished.  We use Hot Rolled Steel for weldments only, and cut a minimum of a 1/8 inch off the stock size to make a nice finished surface for mounting other parts onto.  We still make every effort to consider stock size when creating weld fixture parts.

Two companies that we refer to a lot to find out what stock sizes are available are Central Steel and McMaster Carr.  for cold and hot rolled steel and aluminum and sheet metal.  They have angles, tubes, rounds also. for harder steels or other metals not found in the Central Steel catalog such as A2  and 4140 PH (Pre-hardened).

So Product Design vs Machine Tool Design.  If you have experience in both, what differences have you noticed?

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Weld Fixture Design – Discover how to Adjust Location of Straight Action Clamp

Discover how to adjust the location of a straight line action clamp.

Often times, when designing a fixture we need to think ahead to where else adjustments might be made that will affect the area of the design we are working on.

In this video lesson we discuss using RAPid Plate ™ RB09 in combination with metal shims and over-sized holes to locate a straight line action clamp sub assembly.

So in this lesson we talked about sub assemblies. We have found them very useful.  In a future blog I will talk about how to create them, use them, and still have your whole BOM shown on the main assembly drawing.

Now, those of you who read this blog have a special treat.  Rentapen has just launched it’s beta for downloading 3D models of RAPid Tooling Components.   Please help us test it out and leave a comment below. Go to Rentapen’s home page and click the last item in the top menu, “Order 3D Models”.

Let me know what you think!

The Queen