I was digging through my archives and found the drawing files for this simple project to help you get to those hard to reach places. This is a great first time project for the CNC enthusiast.


A couple years ago I was asked to do a CNC demo at a local event.  I had a bunch of 5/4 scrap poplar from another project.

What could I make?

It would have to be simple and quick.

I got it, a backscratcher!!

 

 

 

My Backscratcher Workflow

Sorry I dont have any videos of this project. I'm going from memory but managed to piece together this workflow. I hope it will help you making your own backscratcher.

 

CAD

I don't need a full 3D CAD program for this project. It can be done very simply as a 2.5D project. 

In a 2.5D project you design the part as a simple 2D drawing. Here I used Corel Draw to layout my shape. Once the design is complete, I select the object and export it as a eps file.

Why eps? It seemed to work the best going from Corel to my CAM software, Vcarve.

CAM

The CAM software is used to create tool paths based on the object created with the CAD software.

For this project I am using VCarve Pro from Vectric. Cut2D, VCarves little brother would have worked exactly the same, as would Aspire, also from Vectric.

The eps exported from Corel works perfect.

For this object I only had to create a single profile path to cut out the backscratcher. The software even added tabs so the cutout would not separate from the stock as it is being cut.

When creating profile tool paths, you tell the software how thick your router bit is, where to cut (inside, outside, on) on the line. You tell the software how deep to cut and how much to cut on each pass. You also tell the software how fast to cut.

All Vectric CAM products have the ability to show you what your finished job will look like when cut. This can help you identify problems before you start the milling.

Once I am happy with the part, I export the Gcode file.

 

Control

I currently use Mach 3 to control all my CNC machines. Mach 3 takes the Gcode file and via your hardware causes the motors on your CNC to do its thing.

This is where the rubber meets the road. Mach 3 allows you to see each Gcode command as it is executed in real time. 

 

The Files

The drawing files provided contain Ai, DXF, EPS, and CRV formats. The CRV (Vcarve) files also included tool paths. If you are not using 1" stock you will need to make those changes to the Vcarve settings.

Backscratcher Drawing Files

I used a two flute 5/16" spiral router bit for this job. I used a 1/4" cut depth and cut at 50 IPM. Use these as starting points for your own CAM software. These settings will work OK with pine or other softwoods. If you are doing this in harder woods you will need to experiment a little.

Other Links

Here are a few products that may help you with this project.

I used a 5/16" router bit because most have a 1" cutting depth. 

5/16" Router Bit

The 5/16" router bit can be a little expensive. Here is a link to a 1/4" bit that will work as well.

If you have a smaller CNC, this may be the bit for you. 

1/4" Router Bit

 

Don't have a CNC, check out building your own KRmx02:

Building the KRMx02 CNC Workbooks