Computer-Controlled Machining

Materials used

• Plywood 122 cm x 240 cm, 12 mm thick
• Endmill bit 1/4"

Note: When designing the pieces it is important to do so with zero tolerance, since the tolerances (the "kerf") will be calculated automatically by the software.

1. Open a new file and import the vector document (i.e., the DXF file from the SolidWorks drawing).

2. Enter the material dimensions in millimeters in the software. These measurements are only used as a reference to avoid going beyond the physical material.

Mistake I made: In this case, I set the material in horizontal orientation, which is incorrect since the machine bed is vertical — this can cause errors. Please note that the screenshots shown below were taken with the material set horizontally; however, I later corrected it to vertical and repeated the entire process shown here.

3. Using the "Measure" tool, I verified that the space between all pieces and the edge is greater than 19 mm (which is three times the diameter of my 1/4" bit).

Note: Clamps will be placed in the corners of the work area, so nothing should be placed there.

4. Using the trim tool, the lines of the ovals that will serve as the furniture's rails are removed, so the software does not interpret them as cuts.

5. Then all pieces are selected and the "Join Vectors" button is clicked.

6. Next, the "Fillet" option is applied to create a rounded corner on all female (internal) joints in the piece, to prevent the CNC from curving the material removal and blocking the correct fit with its counterpart.

1. Select all the cuts by holding "Shift" and clicking on each shape.
2. Select the "Profile" option to perform the cut.
3. In the panel that opens on the right, click "Select" in the tool section.

Note: There are three types of cuts (the kerf is calculated automatically):

• Outside: Passes outside the line; used for all male pieces and external cuts.
• Inside: Used for female joint pieces.
• On: Cuts directly on the line; mainly used for engravings.

4. Check the "Add tabs to toolpath" checkbox to add tabs that will hold the pieces in place and prevent them from flying off. Set the tab size — the one that has worked well is 6 mm x 4 mm.
5. Click "Edit Tabs" to let the system place them automatically, then adjust their positions as needed.

Note: Tabs should not be placed in hard-to-reach areas for the machine, such as the corners of pieces.

6. Finally, give the layer a name with the parameters you set, then click "Calculate". A warning will appear saying that the cut depth exceeds the material thickness — this is fine, just ignore it. A "3D" tab will open where you can preview how the cut will look.

1. Select the pieces using "Shift" and clicking on them.
2. Select the "Pocket" option from the menu to create the furniture's rail slots.
3. Set the desired pocket depth.
4. Select the same tool and configuration used for the cut.
5. Give the toolpath a name and click "Calculate".

1. Click "Preview Toolpaths".
2. Click "Simulate All Toolpaths".
3. Click the play button to start.

Layer organization

It is vital to organize the layers in the following order:

1. Engravings
2. Small cuts such as female joints
3. Large external cuts

1. Click on "Save Toolpath".
2. The available save formats are:
   • Red CNC: Mach 2/3 Arcs (mm) (*.txt)
   • Black CNC: Asia Robotics
3. The toolpath(s) must be saved in G-Code format.

Note: Export in both formats so you can cut on either machine.