Three Legs Under a Triangular Top.
This 3rd example for the final beginning workshop class is to show students both the joinery needed to make it, as well one alternative to 4 legs for this final beginning workshop project. It is also another example of detail continuity throughout the design.
The table is made from 4/4 thick (approximately 7/8" actual) face grain white oak. For the top the oak was ripped into slices 1.125" wide, then tipped 90 degree to be glued up into a 1.125" thick panel. Doing this reveals a more interesting quarter sawn view of the wood grain, and reduces width expansion/contraction by roughly 2/3. After glue was dry the blank was scraped flat on one side, then sent through the planer (or horizontal drum sander) to clean up. It ended up 1.0625" thick. The CNC was used to carve the bottom face and cut out the profile. A trim router with a small 1/8" round over bit around the top edge followed.
Still fitting within a 9 inch square, the CNC carved bottom face reveals it will connect to a triangular center post.
 |
| Bottom Side. CNC Carved |
 |
| Top Side. Rounded Edge |
The center post won't extend down to the floor, but rather just far enough to connect to stretchers extending from 3 legs. The center post may be made from one solid (or glued up) block using the rotary axis, or 3 pieces mitered together with a void in the middle.
 |
| Center Post Showing Top Tenons. |
Tenons cut on the top will match and slip into the mortises cut in the bottom center of the table top. Three tenons rather than a single center tenon have more glue contact surface area, Spread the load closer to the post perimeter, and have bridges between them to weaken the top less.
The legs stand on the floor, but don't extend all the way to the top. The leg outer profiles matches the corner shape of the top. Their top edge is notched to match/echo the underside shape at the corners of the top above them.
 |
| Leg |
 |
| Inside Mortise |
 |
| Triangular Stretcher Option |
For some technical variety one could make the center post from 3 mitered pieces. Then use the center void as a wire chase to feed power to an embedded table top wireless charging puck. The wire chase could continue though one stretcher that is glued up from two halves that have a groove running down their middle. A leg made from two halves could also have a wire chase from the stretcher down to outlet height. Just make sure the cable is in place when stretcher and leg halves are glued up.
In summary this project encourages students to think beyond rectangular shapes. It teaches them how to make more interesting 3D shapes for furniture parts using the technology available. It opens their minds to think about propagating details throughout a design to aesthetically tie all the parts together. It lengthens the story that can be told about their design. It is this story of the design details more than a quick glance at it that makes it memorable and desirable.
Some related educational projects:
Making Sample vs. Making Projects.
Calculating Actual Project Costs.
C
No comments:
Post a Comment