Before starting the project, it is calculated how much will be the CNC machining cost. While manufacturing the parts with the CNC machining process, one should try to minimize the machining cost.
There are some fixed requirements from the client which can’t be modified but still, there are different methods to make CNC machining cheaper:
A lot of machining costs can be saved if you are required to make parts in larger numbers. The cost per unit part will be decreased because you have to design the identical part once. In this case, you are required to repeat the machine setup for each part which also results in a decrease in production cost.
Be wise in Material Selection
In order to reduce the cost of the product, special attention should be paid to the selection of materials. Materials with good mechanical properties will have lower processing costs. Keeping in mind the function of the product, you must choose the best available material that is easy to process. There is a difference in price between plastic and metal materials.
If some features of the product don’t affect the functionality, the design should be optimized to avoid machining those features which will reduce the production cost.
a. Consider Hole sizes and profiles
When fabricating your CNC parts, you should ensure that your part features (e.g., holes, contours, slots, threads, etc.) can be made with standard toolings commonly available. Custom hole and thread sizes will need special tools, which can be quite expensive. There are many references about standard sizes used in the machining industry available on the internet.
b. Avoid thin walls and deep cavities for your part design
Thin-walled parts and deep cavities are very challenging to achieve through machining, and they are usually prone to dimensional inaccuracies. These part features tend to cause vibration on the part and sometimes lead to the scrappage of parts.
c. Avoid requiring very tight tolerances as much as possible
Parts with tighter tolerances are significantly harder to achieve, hence making it expensive. Only control a dimension if it is essential to the part’s overall functionality. One great piece of advice we can give you is to design your part to have one common reference point or datum. This will both help you and the machinist. First, you, to minimize the dimensional controls you need to put on a part, and second, the machinist, to lessen the inspection time, which also reduces costs.
d. If complexity is inevitable, convert one piece of that complicated part into modular components instead
When one part gets too complex, it is advisable to split one whole part into multiple components to be assembled. This will make machining much easier and simpler. It significantly reduces set-up time, lessens machining operations, and optimizes machining time. This is a strategy commonly used by designers to promote a part’s manufacturability and lessen its fabrication cost.