If you’re interested in making things (and since you’re reading this, we’re going to assume you are), you’ve almost certainly felt a desire to make metal parts. 3D printers are great, but have a lot of drawbacks: limited material options, lack of precision, and long printing times. If you want metal parts that adhere to even moderately tight tolerances, a milling machine is your only practical option. There is, after all, a very good reason that they’re essential to manufacturing.
However, it can be difficult to know where to start for the hobbyist who doesn’t have machining experience. What kind of milling machine should you get? Should you buy new or used? What the heck is 3-phase power, and can you get it? These questions, among many others, can be positively overwhelming to the uninitiated. Luckily, we — your friends at Hackaday — are here to help give you some direction. So, if you’re ready to learn, then read on! Already an expert? Leave some tips of your own in the comments!
WHAT KIND OF MILLING MACHINE DO YOU NEED?
Before we get into the details of what configuration of milling machine you’ll most likely want to buy, let us first point out that we’re only going to be talking about manual milling machines in this guide. CNC mills are a whole other beast, and they’re going to get a guide all to themselves. Manual and CNC mills share a lot in common (CNC mills are often just converted manual mills), but CNC mills have additional requirements that would over-complicate this article. So, we’re just covering manual machines in this post.
Modern milling machines are divided into two basic types: horizontal and vertical. This determines whether the machine’s spindle axis runs up and down, or side to side. Both types of machine will often have heads, columns, and tables that tilt or swivel, which means both kinds can be used for a lot of the same tasks. However, certain jobs will be easier on one machine than the other.
The difference between the machines, in practice, is more pronounced than just which way they’re oriented. A vertical machine will have the table mounted perpendicular to the spindle’s zero-tilt position, while a horizontal machine will have the spindle mounted parallel to the plane of the table. This introduces a fundamental difference in what kinds of jobs are practical on each type of machine.
A horizontal milling machine’s primary strength is the over arm, which constrains the rotating arbor on two sides. This gives it incredible rigidity, and allows the machinist to take very heavy cuts that would introduce more side load then a vertical machine could handle. The strength is so high that it’s entirely possible (and common) to stack multiple cutters on the arbor in order to cut, for example, a flat table with slots all in a single pass. This makes it well suited to surfacing jobs, cutting grooves and slots, and similar tasks where the part is flat in one axis.
Read more: TIPS FOR BUYING YOUR FIRST MILLING MACHINE