by Jason Ross
With two tools, you can build all others. Two tools to rule them all…
A mill and a lathe.
Operating a manual lathe or mill is a dying art. With the advent of CNC machines, most guys just learn how to program a part into existence, and even that work has mostly moved overseas.
But every red-blooded man should know how to perform basic operations with a lathe, mill and a welder. In a collapse, there are about ten zillion things you will eventually need that can only be turned or milled once Chinese injection molding and casting go away.
In some ways, a mill is more useful than a lathe. However, when you need something cylindrical or threaded — which is surprisingly often — only a lathe will do.
A mill can be compared to a drill press, only the table of the mill moves side-to-side, back-and-forth and up-and-down in a very precise and measured way. Instead of a drill, a mill usually uses “end mills” that remove material from the sides as easily as from the tip of the tool (a drill bit only removed material from the end.) Plus, the mill applies much better control of speeds. Except for cylindrical parts, the mill can be employed to make almost anything.
A lathe “turns” things — meaning that it takes material off in a cylindrical fashion. There are wood lathes and metal lathes. Most wood lathes are for turning furniture legs and the like and cannot be used to turn metal. Metal lathes, on the other hand, can generally turn almost anything wood, though they’re not ideal.
Any metal lathe will have “speeds and feeds” controls and will be able to turn threads by cutting a little triangle out of material while moving across its face at a measured rate. This is a challenging application for a lathe, but is relatively simple to figure out once you understand the basic functioning of speeds and feeds.
The part being worked on by the lathe is held by the “chuck” which has three or four jaws that grab the cylinder of metal stock that you’re machining. The “carriage” firmly anchors the “tool holder” which holds a “tool” that does the cutting. The “carriage” rides on the “bed.”
The speed of which the carriage goes back-and-forth or across can be automated by the speeds and feeds, which gives you the best cuts. In other words, the tool can cut without you turning the handwheels of the lathe.
At this point, some safety issues become clear. If your ADHD takes over and you start daydreaming about your girlfriend, you’re likely to run your tool holder into your chuck or your part. The results are spectacularly bad. Unless your father traumatized you every time you effed-up the lathe (as I did), you’ll just have to pay really close attention.
One great addition to a lathe is a D.R.O., or Digital Read Out. This tells you in very fine increments where your tool is located and how much you’re going to remove by making your next cut. It’s a cheap and awesome addition to a lathe or mill.
If this all sounds way over your head, let me assure you that it’s not. You can buy a metal lathe for under $1,000 and go on to dominate the shit out of your kid’s Cub Scout pack at Pinewood Derby time. Watch this video and I’ll share the basics with you. The other stuff, you can figure out a bit at a time. Or, get a machinist friend to walk you through a few test parts.
Personally, I’ve made tons of parts for my ocean-going scuba boat out of stainless steel on my lathe and mill. I can’t describe how much pleasure these cool, little parts have given me throughout the years. Just the hinge pins in the video will provide years of contentedness as I brush past them on the way to my tomatoes, knowing “I made those.”