Despite the emergence of newer, more advanced technologies such as 3D printing, CNC machining remains a cost-effective method of producing goods and products on demand. Of course, the main reasons behind this include the many benefits it offers businesses.
These benefits include high quality parts, fast lead times, high accuracy and low tolerances. Short lead times also mean that businesses can get the parts they order quickly, thus reducing time to market considerably.
Note, however, that you should also know how much your CNC machining project will cost. This way, you can always be prepared and find ways to reduce your costs CNC machining costs as much as possible.
Definition of CNC machining
The cost of CNC machining varies depending on a number of factors, including material costs, equipment costs, labour costs, energy costs, tooling costs, etc. The following is a general cost breakdown.
Material Costs
One of the main factors affecting how much you spend on cnc machining is the cost of the material chosen, such as steel, aluminium, stainless steel, etc. The cost of CNC machining can also go up or down, depending on the type of material and how much is purchased.
Time and labour costs
Machining time and labour are the main factors affecting the cost of CNC machining. Generally speaking, the higher the skill level and working hours of the operator, the longer it takes to operate the machine and the more it will cost.
Equipment Costs
When you use a 5-axis machine, the cost is generally a little higher than when you use a 3-axis machine, but 5-axis machines are more accurate, depending on the complexity of your part.
Material Finishes
If you add a surface finish to your chosen component or part, the final appearance will improve. Finishes can also increase the ability of a component to resist and withstand harsh environments. Note, however, that this benefit can also significantly increase the cost of CNC machining.
Design Tips to Reduce CNC Machining Costs
Optimised design
Simplify the design by reducing unnecessarily complex structures and simplifying processing steps. If a design is too complex, consider breaking it down into multiple components and assembling them using fasteners.
Avoid unnecessary text engraving
Removing all letters and text from a part can help to reduce the cost of cnc machining, as you will need to perform more operations to achieve it, which will take more time. If you do want to add text, consider using surface finishing processes and techniques such as painting or screen printing.
Limit the depth of the cavity
The reason is that it requires the removal of several materials, which is not only time-consuming but also inefficient and wasteful.
You should remind yourself of the limited cutting length of CNC tools. Expect these tools to work more efficiently when you cut cavities that are twice or thrice as deep as their diameter.
If you want to lower the cost of CNC machining, then limiting the depth of cavities up to four times their actual length can help. It also helps to make appropriate adjustments on the internal corner radii.
Finding alternative materials
One of the easiest ways to keep your budget in check (assuming your requirements are met) is to switch to a material that fits the machine better or is cheaper. Our material selection includes a range of metals and plastics, each with its own engineering properties, aesthetics, machining considerations and material costs. In general, it is cheaper to machine softer metals than harder materials.
Copper is a good conductor of electricity, but it is much more expensive than aluminium. Although aluminium has about 60% of the electrical conductivity of copper, the weight and cost savings of aluminium may make you reconsider using aluminium.
Titanium alloys are strong, corrosion-resistant, and lightweight, but are expensive to extract and process. Aluminium alloys, stainless steel, and carbon brazed dimensional composites can be less expensive alternatives to titanium.
Increase the thickness of thin walls
Thinner walls are, surprisingly, more cost inducing than thicker walls in CNC Machining. This is because thin walls can distort because the thinner material will naturally be weaker and prone to vibrations. This can cause chatter, which slows down the machine speeds, resulting in additional costs and machine operator time. Multiple passes at low cutting depths for thin walls, machining these more accurately can always be a problem.
By expanding thin walls, to a more manageable minimum width, walls will be sturdier and tolerate faster machine processes.
Top tip: If you need thin walls, consider alternative machining methods, such as sheet metal fabrication.
For more information about CNC machining, or our CNC machining services, please contact us for a free 24-hour quote.