One of the advantages of CNC machining a prototype is that you can adapt the technology for rapid prototype manufacturing. The CNC programs are extremely flexible and that is very helpful when you are not yet completely satisfied with the design.
That way, once you’ve manufactured the first prototype, it will be much easier to manufacture consecutive variations. That is, of course, if you are dealing with the same company both for the first and the consecutive options.
That is highly preferable since in some cases the machine shop may have to set up the fixtures in a special way (they have those “Lego” – type fixtures that can be easily assembled into any configuration).
High Precision Prototypes are only available with CNC machining
CNC machining is the most conventional among rapid manufacturing processes and partly due to that and its specifics, machining is the most precise of all the methods. One of the reasons for machining precision is the rigidity of all the elements in the machine tool.
Another reason is the precision of the machine tools themselves, they are manufactured to a 0,0001 mm tolerance and with mirror-like surface finishes. In addition, such manufacturing methods as casting, forming, and 3d-printing use a phase change in the material ( it is heated to a liquid or plastic form and its form is changed, afterward, it cools down), and that brings about a lot of deformation during the cooling phase.
CNC machining uses a lot of coolants to keep the part from overheating and thus offers increased quality. In general, if you want your parts done with a precision of up to 0,012 mm and a surface finish of Ra 0,32 microns, you can rely on CNC machining and nothing else.
You can make the prototype from the intended material right away
A lot of rapid manufacturing techniques for design validation rely on material substitution. For example, 3D printers mostly use ABS plastics and all the casting and molding techniques – some kind of polymer.
polymer-compounders.com is one of the plastics manufacturing in the UK. They also have ABS polymer products, compounds of Acrylonitrile, Butadiene, and Styrene.
CNC machining can process literally any material known in the industry. From the softest flexible ones ( you must freeze them before machining so that they become brittle) to the aluminum alloys and up to the most complex nickel and titanium alloys.
The cutting tools are so hard they can take even some of the ceramics and composite materials. So, if it is important for you to test out the design specifications on the required material ( for some cases where prototypes are later to be used for strength tests or heat exchange experiments), you should stop on prototype CNC machining.
CNC Machining Ensures Repeatability
CNC machining is the oldest compared to other processes and is very well-researched. That can’t be said about other prototyping techniques.
For example, 3D printing was developed during the current century and scientists don’t even understand all the processes that happen when the laser singers the powder or cures the plastic.
That being said, CNC machining is the most stable among the manufacturing methods. So, if you want a couple of prototypes or perhaps more than ten and you want all of them to be identical, then you should choose CNC machining.
The CNC Machining Costs and Lead Time are Low
Design Validation is one of the primary steps in product manufacturing. It is a phase where you are not sure about the final design yet. Having completed the design validation prototype, you will probably find a lot of issues and will have to redesign it. After that, you’d have to make another prototype from version 2 of your design.
The number of such iterations may be quite large. And the more the prototype costs and the longer it takes to make, the less efficient your product will be. In the competitive market, the one who issues something innovative first is often the most successful.
Modern CNC machine tools are extremely flexible and can be programmed and reprogrammed in a day. They can machine at tremendous speeds and feeds so you can get your prototype in less than a week. The speed of CNC machining May be lower than that of 3D printing but if you compare the quality of the final product, the choice is obvious.
CNC Machining Services are Common
CNC machining shops can be found in every big city in every country and the majority of them ship nationwide. Such open access makes the market very competitive and influences machine shops to constantly improve, lowering prices and increasing quality. Some countries have improved their processes so much that they can be called international leaders in prototype CNC manufacturing.