Today, most milling is done by machines, but you still have to understand the different components to manipulate your rotary cutters correctly. Check out this quick guide for a refresher on calculating milling force and other values.
How To Calculate Milling Force
Figuring out how much force your rotary cutters exert when they cut keeps you from milling too far into a material or making too small of a cut. The simplest way to calculate this force is with a milling force calculator. Input the Brinell Hardness and ultimate strength of your materials, and then add your rotary cutters’ diameter and the total number of blades. Type in your desired depth and width, as well as the speed of your cut and some statistics about your machine’s efficiency.
If you want to verify your results or complete the process on your own, the formula for milling force is Ft = σ × A × Zc × Ef × Tf. In this case, σ is the ultimate strength, A is the area of the material you’re working with, and Zc is the total number of teeth on your cutters. Ef represents the engagement factor, or the depth of the desired cut divided by the diameter of your cutter, while Tf stands for how quickly your machine gets worn down.
To avoid making errors in either the calculator or your own calculations, make sure that you’re using either the metric system or the Imperial system consistently. Also, remember that formulas such as the one for milling force cannot account for every eventuality.
The Ins & Outs of Metalworking Tools
Using metalworking tools such as an indexable end mill starts with safety. Never operate a tool without having an experienced metalworker show you what to do first. Always wear safety goggles to prevent shards of metal from getting stuck in your eyes, and wear thick gloves to prevent cuts and scratches.
Also, remember that different types of metal handle cutting and shaving differently. Tungsten, chromium, iron, steel, and other metals with high ultimate strength values require more force than softer metals such as copper, titanium, aluminum, and brass.
Other Useful Formulas
Here are a few more formulas to know before using a solid carbide end or a similar tool. To figure out how many feet of material your rotary cutter can mill each minute, multiply the total area of metal that you can feed into your machine each minute by 3.82. Divide this product by the cutter’s diameter for your speed in revolutions per minute.
To calculate your machine’s output in horsepower, figure out how many cubic inches of metal your machine removes each minute. Then, multiply this value by the metal’s martensite finish. For example, aluminum has an Mf of 0.3. If your cutter can remove 100 cubic inches of aluminum per minute, your machine operates with 30 horsepower.
To avoid accidents and improper cuts, always review these essential milling formulas and calibrate your machine appropriately before starting a job.