Lathes cut rounded edges, threads for bolts and screws, interior threads for nuts, and cylinders of all kinds. But boxy, square-edged parts? That’s work for a mill! So goes the conventional wisdom, at least. The truth is, there’s always been a bit more overlap than it seems. A mill can, in a pinch, perform some lathe work; likewise, using a lathe as a mill has always been possible – just severely limited.
Here are four tips for producing boxy parts on a CNC-lathe; some are a bit more practical than others, but there’s a point to all of them!
Tip #1: Buy a Mill!
Ok, this is the “less-serious” part we warned you about. It’s worth noting up-front, however, that lathes being used for mill-work have several limitations. In general, lathes are smaller, meaning that the workpiece will need to be smaller. Along with that size limitation comes difficulties in mounting or holding the workpiece. Producing boxy parts on a CNC lathe is possible – but sometimes, you may want to think about just buying a mill instead!
Tip #2: Newer lathes are better
Here’s the crux of the matter: producing boxy parts on a lathe is really only possible on a live-tool lathe. A live-tooling lathe provides power to the tooling head itself. In other words, it’s not the traditional picture of a lathe with a turning workpiece and a stationary tool. Because of the power to the tooling head, and a range of movement along multiple axes, live-tooling lathes can actually perform milling operations within the CNC program.
However, live-tooling lathes are newer and tend to be very expensive. The greater the range of movement the tool is capable of (i.e., the more axes), the greater the price. Thus, producing boxy parts from start to finish on a lathe may be an expensive procedure. With that in mind, here are a couple more tips to help you know when, what, and how to make a boxy part entirely with your CNC lathe.
Tip #3: Keep it small
As mentioned before, lathes tend to have smaller working areas than mills. Large, boxy-shaped parts may be entirely impossible to create on your lathe. Not to mention that the cutting head on a live-tool lathe takes up a significant amount of room itself. If you need to make a boxy part on your CNC lathe, keep it small!
Tip #4: Limited-edition parts
Mills excel at high-volume parts. They’re more economical, more efficient, and obviously better suited to boxy shapes. So if you need to create a box-shaped part in high volume, you probably need to go back to Tip #1 and buy a lathe.
On the other hand, live-tooling lathes allow to you perform almost every operation necessary to create a new part, from shaping to milling to drilling to turning, all on a single machine. And CNC programming means you can create a new program for any part that comes through the door.
Combined, this means that a skilled operated with a CNC lathe can make almost any part necessary, whether it’s making 1,000 pieces or just a single one. Use your mill to produce “run of the mill” parts (pun intended); use your live-tooled CNC lathe to create parts for small production runs or even unique parts.
The most critical element to the process of creating boxy parts on a CNC lathe is the human operator. It’s the operator who creates the program and inspects the final product, and he or she is the one who decides which pieces will be milled or turned on a lathe. But in the right hands, producing a boxy part on a CNC lathe is entirely doable, and might even make more sense than using a traditional milling machine.