Wednesday, May 10, 2017

A Tutorial Course About Building a CNC Router

What does the word CNC mean? CNC actually means Computer Numerical Control. This means a computer converts the design produced by Computer Aided Design software (CAD), into numbers. The numbers can be considered as the coordinates of a graph and then they will be used to control the movement of the cutter. This way the computer controls the cutting and shaping of the material.


Our Build a CNC Router course is coming up again in April, and I’m really excited about it. I love building, programming and using CNC routers, but seeing the photos from students in this class is even more fun. So many people have built their own machines over the past year, and they’ve shared photos of the process and their finished projects in the course galleries.

The project is fairly straightforward, and anyone with a few basic tools and woodworking skills can build it. In previous sessions, some people followed the plans exactly. But a few students made some simple modifications and improvements. One of the first tweaks to the design was the drag chain shown above that keeps the wires organized and out of the way. For just a few dollars, the student who built this machine was able to make a huge improvement to the look and performance.

There are several mechanical components in the project, and I’ve linked to a website where students can purchase them. But it’s possible to save a few bucks by making some of those components, which is exactly what Kevin R. did to the machine shown above. There are four metal collars on each axis that hold the shafts in place, but they could be made out of MDF. That’s a good way to save about $50, and you can see how this works in the photo.

Workholding is one of the biggest challenges in CNC routing. Big commercial machines use vacuum systems to keep parts in place, but smaller machines can make use of mechanical clamps. Tony S. routed a couple of dados into the X-axis of his router and installed t-tracks. Now he can use clamps and feather boards to hold workpieces during routing. Tony’s build should be encouraging for people who think they’re too set in their ways to try this new technology. He’s getting into CNC at 70 years old.

My favorite modification is from a student named Ray S. I included two SketchUp models in the course: one for a fixed-gantry machine and another for a moving-gantry version. Most students have opted to build the fixed-gantry machine because the course focuses on that one. But Ray built the moving-gantry CNC. He also made a few sweet upgrades. To provide additional support for the X-axis, he set two pieces of tube steel into notches in the front and back of the machine. He added an emergency stop button, which any experienced CNC operator can tell you will come in handy sooner or later. In addition, his machine is light and strong because he built it with 3/4” plywood instead of MDF.

As much as I love these modifications, I was thrilled when I saw the first student photos of the machine exactly, or in some cases, almost exactly as I designed it. Kent D. was one of the first students to finish the project. That’s Kent’s CNC router in the photo above.
Build a CNC Router is always a fun course, and I think that’s because there’s so much interaction between students. When someone asks a question in the discussion, other students often reply before I have a chance to put in my two cents. I’ve had mechanical engineers, electricians and machinists in the course, and they’ve all helped out with valuable input. Now this is why we do online courses at Popular Woodworking!



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