Making A Turner's Cube

I saw these on the CNC Cookbook and CNC Zone, and decided that I had to try making one too. I had just started to learn SolidWorks and this was a great first project.


SolidWorks Design

I knew I was going to start with a 2" cube and that I wanted the smaller cubes to each be half an inch smaller than the larger cube - i.e. the four cubes will be 2", 1.5", 1", and .5" per side. The inside cube dimensions are determined by the counterbore depths, and how much of each edge is revealed is determined by the counterbore diameter. I got the idea of using an overlap parameter from Robert Warfield of the CNC Cookbook.

You can see the three calculated diameters based on the scale factor in the left hand window pane. I then rounded the calculated values for the final diameters for the three counterbores (Cut-Extrude1 to 3). This modeled the counterbores on the front face, which then had to be patterned on to the other five faces of the cube. That was done using the two circular pattern (CirPattern1, 2) features. The first circular patteren copied the counterbores on to the sides and the back, and the second circular pattern copied the counterbores on to the top and bottom (the two circular patterns are based on two perpindicular axies).

Here's a screen capture of my SolidWorks design file:

Click HERE to download my SolidWorks design file.


Lathe Face Plate

The CNC lathe I use has both a 4-jaw chuck and a face plate. However, both of these are huge, heavy, and great for large parts; but don't work so well for small delicate parts like a Turners Cube. I made my own face plate for some small square parts in the past and it worked perfectly for this project as well.

The face plate is composed of two parts; a stem and a top plate.

Lathe_Face_Plate_Stem.jpg Lathe_Face_Plate_Top_1.jpg Lathe_Face_Plate_Top_2.jpg

These get bolted together:

Lathe_Face_Plate_1.jpg Lathe_Face_Plate_2.jpg Lathe_Face_Plate_3.jpg

The T-slots fit the same T-nuts as the shop milling machines.

The brass plug helps center some parts (but it wasn't used here).

Lathe_Face_Plate_and_plug.jpg

The face plate is clamped in the 3-jaw chuck and two pieces of right angle Aluminum act as a reference corner. A dial test indicator and the four adjustment screws on the chuck are used to center it.

Faceplate_and_reference_corner.jpg

Machining

Square a 2" cube of 7075 Aluminum. Drill 23/64" and ream a 3/8" hole through each axis. Then put a 5/8" diameter .730" deep counterbore in each face.

Starting_cube_1.jpg Starting_cube_2.jpg
Use the DTI on the counterbore and adjust the right angle pieces as necessary. Then use a SHCS to secure the cube to the reference corner.

Faceplate_and_cube_1.jpg Faceplate_and_cube_2.jpg Faceplate_and_cube_3.jpg

First counterbore:

Counterbore_1.jpg
Second counterbore:

Counterbore_2.jpg
Obligatory action shot:

Boring.jpg

Third counterbore:

Counterbore_3.jpg
Remove two of the right angle aluminum pieces, rotate the cube to another face, reclamp the cube, and then start again. Here, the last face about to be machined.

Last_face.jpg

Finished cube:

Finished_cube_1.jpg Finished_cube_2.jpg

Make another!

Two_cubes.jpg Stacked_cubes.jpg

This page was last updated on 5.December.2009.