When it comes to CNC machining, time is money. For small batch production, part setup, programming, and machine running time often far exceed material costs.
Understanding how the geometric shape of a part determines the required machine tool is an important component of minimizing the number of settings that a mechanic needs to perform and the time it takes to cut the part. This can accelerate the part manufacturing process and save you costs.
Here are three tips you need to know about CNC machining and tools to ensure that you effectively design parts.
1. Create a wide corner radius
The end milling cutter will automatically leave a circular inner corner. A larger corner radius means that larger tools can be used to cut corners, thereby reducing running time and thus reducing costs. In contrast, narrow internal corner radii require both a small tool to process the material and more tool travel - usually at a slower speed to reduce the risk of deflection and tool breakage.
To optimize the design, always use the largest possible corner radius and use a 1/16 "radius as the lower limit. Corner radii smaller than this value require very small tools and the runtime increases exponentially. Furthermore, if possible, try to maintain the same internal corner radius. This helps eliminate tool changes, which increases complexity and significantly increases runtime.
2. Avoid deep pockets
Parts with deep cavities are usually time-consuming and costly to manufacture.
The reason is that these designs require fragile cutting tools, which are prone to breakage during the machining process. To avoid this situation, the end milling cutter should gradually "decelerate" in uniform increments. For example, if you have a 1 "deep groove, you can repeat the 1/8" deep cutting of the pin and then perform the final precision machining with a depth of 0.010 ".
3. Use standard drill bits and tap sizes
Using standard tap and drill bit sizes will help reduce time and save on component costs. When drilling, maintain the dimensions as standard fractions or letters. If you are not familiar with the dimensions of drill bits and end mills, it is safe to assume that traditional fractions of one inch (such as 1/8 ", 1/4", or integer millimeters) are "standard". Avoid using measurements such as 0.492 "or 3.841 mm.
For taps, 4-40 taps are more common and usually more usable than 3-4 taps.
