As some readers may know, in addition to blogging here on Milling Around, I also contribute a quarterly column to Digital Machinist magazine about CNC machining topics of interest to hobbyists and small garage shops. The Fall 2012 column is set to be on newsstands in the next week or so. You can find it at major bookstores- Barnes and Noble comes to mind, but I know its available elsewhere as well. Lots of great content, including many project ideas. The topic of my Fall 2012 column is engraving - and in particular, drag engraving. These are great tools for part marking, whether it be logos, serial numbers, graduations, or similar. Probably the best thing is how easy it is to get a very professional looking engraving using simple 2D cutting paths from Vectric Cut2D or similar. Drag engraving works well on just about any material, thanks to the diamond tip. Here's a couple examples of the drag engraving process in action. First, in Acrylic Second, in 4140 Steel. You'll notice that they are spring-loaded, which makes the process forgiving if the workpiece isn't perfectly flat with respect to the spindle. All you need to do is preload the the tip a few thousandths of an inch ( a bit of experimenting with preloads and feedrates is usually necessary to really dial in the process). Our TTS drag engraver kit comes with two springs of different stiffness. There are also two different point angles available, 90 deg and 120 deg. If you're interested in trying any of these tools out for yourself, you can buy those tools here: Purchase TTS Drag Engraver. Here's what things look like up-close: 
The height of the "TM" is approximately 0.050". Line width is approximately .005". Feedrate in this particular case was 30 ipm. You'd need a very fast spindle to do that with a rotary engraver. *By the way, If you're visiting from the magazine and would like to subscribe to this blog, its easy, simple, and free - just use the links on the upper righthand corner of the page to register and updates will be delivers to your email as they happen. If you've never heard of Digital Machinist and would like to subscribe to that magazine, Home Shop Machinist, Machinist's Workshop, or any of the other Village Press titles, that's easy too. Click here to get started. Digital Machinist also sends out very nice email tips through out the year - and you don't even have to be a subscriber. Click here to sign up for the Pass Along e-Tips Special thanks to SDM Manufacturing for the videography
