Most of the time, machinist’s focus on the hardware aspects when they think about surface finish: –  Do I have the right feeds and speeds? –  Is my setup and machine rigid enough? –  Is there too much runout on the spindle? This is definitely the right place to start, but it’s not the end of the story. A great many factors affecting surface finish are tied up in the CAD/CAM software used to create the part program. For example, the part in the photo on the right exhibits a faceted surface finish. This is definitely a software issue (although there are certain servo mis-tuning situations that can lead to that sort of thing). Let’s take a look at some of these critical software issues that affect surface finish:

One of the murkiest (and most interesting) topics in the world of CNC is tool and moldmaking. Moldmakers have been around for a very long time (longer than CNC), and there is a mystery and art to the craft.

When it comes to machining, there are always a bunch of ways to do the same cut. Ask five machinists how to do a specific operation, and you’re bound to get eight different answers. Face milling is no different.

Learning to machine has long been considered a journey. There is always something new to learn, as well as skills and techniques to perfect. Machining knowledge often can’t be just simply taught, it often requires hands-on learning and some serious time at the machine.

When you get into machining, the first tool often used is an end mill. It’s simple, it’s fairly straightforward on purpose, and it’s the universal standard tool for machining. But, we all know that that is just the beginning – tool boxes fill up because there are an endless number of options for tooling. One tool that is often misunderstood, or even disregarded, is the slitting saw. While these saws are often relegated to very specific operations, they can be an invaluable addition to your shop.

Machinists are familiar with spot drills–they’re stub length and have few or no flutes.  These little drills are designed to be extremely rigid so that they can precisely spot a hole for a twist drill.  Maximum meat in the shank keeps them on target.  The goal is use the spot drill to make a little dimple in the work-piece that keeps the twist drill from walking so the hole winds up in the right place.