What does 5-axis machining really mean?

What is 5-axis Machining? This term is often thrown out to convey a level of complexity or quality associated with a product, but rarely is the term fully understood by consumers. In this blog post, I hope to clear up any misconceptions of what 5-axis machining is, and effectively convey what the benefits really are.

In order to fully understand the benefits of 5-axis machining, one first needs to understand how traditional 3-axis machining works. In a traditional mill, the machine is only able to move in 3-axis x, y, and z. This means the part can only be approached from above, along the z-axis. For many parts, once it has been machined on one side, the part will need to be removed from the vice and re-clamped in a different orientation, in order to gain access to features located on the other sides. On average this takes anywhere from 15 minutes when custom fixturing is not required, to 3 hours when custom fixturing has to be made in order to hold the part securely. Now imagine if a six-sided part like a cube needs to be machined on all sides. This action of reorienting the part could add days and thousands of dollars to the cost of the manufacturing of the part. In order to combat this added cost, parts are typically manufactured in large volumes, amortizing the added fixturing cost over hundreds or thousands of parts to greatly reduce the cost per part. A 5-axis machine helps eliminate the multiple setups by rotating the entire vice and part. A 5-axis machine is very similar to a 3-axis machine, but with the addition of two rotating axes that rotate around the y and z-axis. These rotational axis are called the b, and c axis. By rotating these axis then holding the part in a new orientation 5 of the 6 sides of a part can now be drilled or machined with the machine doing all the reorienting of the part!

The example below helps demonstrate how the cost of manufacturing a one-off part can be greatly reduced by utilizing the rotational axes of a 5-axis machine.

Let's say we have a part that we need to machine. The part is shaped like a triangular doorstop with drilled holes on 3 sides. In order to drill all of these holes, we will have to re-orientate the part 3 times and for one of these operations, we will have to use a custom fixture. Let's say for each time we have to load the part in the machine, it takes 15 minutes to load the part and set the machine up when we just use a vice, and for the one custom set up, it will take 30 minutes to create a custom fixture. If each one of the 3 holes takes 30 seconds to be drilled, the total machining time would be just over 1 hour. Now if this same part was made in a 5-axis machine the part would be loaded one time and the machine will rotate the part so the drill can gain access to the other wholes. This eliminates all but the initial set up turning the machining time from just over an hour to being just 15 minutes, a 75% time-saving. This simple example shows how drastic the time savings, and cost savings, can be for low volume parts. Savings that we can pass along to our customers!