A Simple Box, with Four Different Corner Joints.

This is an assignment sample I made for our beginning Workshop One class.  I designed it to show the students different ways to connect wood at a right angle.  All the joints on this example were cut using my CNC.  Simpler versions of each corner joint can be done using more conventional tools in a woodworking shop.  To show them what a CNC can do if they think out-of-the-box each corner has a feature that would be very difficult to do with conventional tools.

Miter.  The conventional way to reinforce a miter joint would be to use a spline or biscuits to cross between the two halves.  Using my CNC I've made a hidden alternating mortise and tenon row that disappears inside when the joint is closed. Much easier to glue up as this joint won't slide in any direction when clamped.

Tongue and Groove.  Normally a simple tongue in a simple groove is enough to make a good corner joint.   Using the CNC I've added a row of 5 small through-tenons that center the joint and add some aesthetic detail to this corner.

Box Joint. The CNC enhancement for this row of fingers was to make them each a different progressively larger width.  Tough to do using any other jig or tool, but fairly easy to draw up for the CNC to cut them.

Shallow Rabbet.  Conventionally we would reinforced this with screws covered by wood plugs.  Using the CNC I simply cut 3 round tenons from the end grain of the short side to replace the screws and plugs.   The end look is the same. The tenons align the joint.

The bottom is 1/4" (6mm) Baltic Birch plywood.  Rather than install it near one edge of the box, I'11 put it 1/3 of the way up from one end.  This will divide the box into two compartments with one twice as deep as the other.   Flip the box to access each.  The lids won't open unless they are on top. Twisting latches slide into the lid to keep it in place when it is on the bottom. A shallow perimeter rabbet on each lid aligns it to the box. When on top just twist the latches then the top can be lifted out.

4D