Nuts and Volts - September 2014

Getting Started

As with any project, you have to do your research. I needed to answer questions like: What do tombstones look like? How are they shaped? What do they say on them? How are people using them in their Halloween displays? Most importantly: How do I make them on a CNC router? So, I got a lot of great design ideas examining epitaphs and tombstones using Google image search. Unfortunately, most of the models I found required 3D contouring. With that type of work, I would first need to spend the time creating a 3D model and even more hours carving it out.

There are three primary phases to a CNC project:

1) Design: The drawing or CAD model.

2) Tooling: Creating the tool paths with CAM software.

3) Machining: Running the tool paths on the machine.

I am admittedly an impatient man. With time being a finite resource we can never get back, isn’t everyone looking for a faster way? So, let me show you how you can use CNC routers to shortcut the 3D contouring process. First and foremost, you want to create your basic shapes and features using 2.5D operations. This is by far the biggest time saver. I’m talking about pocketing,

profiling, and drilling mainly flat features on flat parts. You then follow it up with a bit of hand sculpting. This marriage between CNC and hand work produces impressive results for this type of project, while shaving valuable time from the process. To start, I needed an inexpensive material that I could get from my local home improvement store that was easy to work with. The obvious choice was 2” thick foam insulation which I purchased in a 4 x 8 foot sheet for about $28. It’s thick enough to allow for a lot of depth and contrast in my design, which really pops when hit by a spot light on my lawn display. I happened to pick up a panel of pink Owens Corning — the one with the Pink Panther mascot (Figure 1). Other brands in other colors should work equally well. By Len Shelton and Melissa Shelton

September 2014 81

Save Time and Money

Making CNC Halloween Decorations

Create complex 3D contoured parts by combining fast and simple 2.5D pocketing and profiling operations with manual finishing techniques.

Post comments on this article and find any associated files and/or downloads at www.nutsvolts.com/index.php?/magazine/ article/september2014_Shelton.

When my friend, Vern asked me if I'd write an article for Nuts & Volts demonstrating how to create a Halloween decoration tombstone on a CNC router, I was psyched. I’m always looking for new and interesting ways to show off all you can do with CNC machines. So, I agreed to give it a shot.