CNC Machining of metal parts
Highlights
Machining is frequently regarded as old technology or disregarded, as it is a subtractive not additive process, however it remains the benchmark by which most processes should be assessed. There are Rapid Prototyping systems that work with metals, such as DMLS, and these are developing niche application areas where their full capabilities can be exploited.
The issues favouring machining are material choice, lack of size constraint, accuracy, and repeatability.
Smartprototype global sourcing results in being able to deliver the benefits of machining at a competitive price point and in leadtimes of typically 10 days or less. (elapsed not working!)
The material options include Aluminium, Brass, and Stainless Steel in 3 axis, or Stainless steel, Aluminium Titanium, and Magnesium in 5 axis.
With the sophistication of today's machine tools and if the quantities are low enough, where a casting is going to require anymore than minimal post machining, then machining from solid should also be considered. Not only is this possibly faster, but also bypasses many of the issues that can occur with casting, such as porosity
Data format for machining is preferably STEP or IGES, STL is sufficient for quotation but not viable for completing the order.
Process Features
Accuracy
Where only a CAD file is supplied a blanket tolerance of ± 0.25 mm will be used, otherwise drawing tolerances will be observed.
Minimum Feature Size
This is a geometry function as with machining it is also related to cutter reach/feature location. Preferably the smallest cutters used would be 1 mm, leaving a 0.5mm internal radius. However 0.2 mm cutters can be used if required.
Layer Thickness
Not applicable, machining is continuous a continuous 3 - 5 axis process.
Bed Sizes
Bed sizes up to 800 x 600 mm are readily available with access to larger machines as required.
Post Processing
This is application specific and prototype machined parts may be manually dressed smooth, left natural, primed or painted as required.
