CNC Design Tips To Minimise Costs

CNC Machining (Computer Numerical Control) is the process that is applied in design and manufacturing and involves the use of computers to monitor and control the operations of assembly line tools such as mills and lathes.

Size

In CNC design, the cost is always a factor to consider. For a typical machine part, the machining cost is determined by the milling time spent on the part, the size of the part and the material used in crafting the part. Although size is the least “negotiable factor” the cost it implies could be minimised by altering geometries used to achieve a design that is less complex and has fewer smaller features. In this way, the cost is effectively reduced.

Common Parts

When designing common parts such as the internal corner radii, it is advisable to design radii as large as possible as most tools will normally require a radius of at least 8 times the depth of the pockets. Moreover, a larger radius is machined faster saving on the lead time. Complex design such as designing parts with pockets that are too deep will require more time and resources during machining. Therefore, ensuring the design is kept as simple as possible would be beneficial as it not only saves time during design but also saves on time and material during machining.

Caution on wall thickness/thinness

The thickness of the walls may be altered during design to your advantage. For instance, thinner walls tend to pose the risk of breakage. For this reason, it is advisable to design wall parts as thick as possible, while still maintaining proportionality to existing form and fit. Thinner walls are subject to breakage during machining which means an increase in cost. Through the automated quoting systems in CNC design, parts in the design that have lower standard part tolerance will be flagged and best-corrected during design.

Material Used

For both prototyping and production, the type of material used could either work in favour or against saving on cost. For instance, using aluminium over steel on parts that require more metallic material would lower the cost. Furthermore, aluminium is much easier for the machine. Material such as titanium is expensive and harder for the machine, therefore, are less advisable. In approximation, titanium may cost up to six times as compared to aluminium.

Necessity of Finishes

Material finishes such as anodising and powder coating would require manual labour. Moreover, if multiple parts require this kind of finishing would mean more lead time which is ultimately costly. Therefore, one standard finish that is more suitable and applicable should do just fine as each individual additional finish adds on labour costs.