Drop-leaf tables
Rule joint
A cove on the leaf and a thumbnail on the center, hinged so the gap closes.
Use when
- A drop leaf has to look continuous when it is up.
Don’t use when
- Do not mix a rule joint with a breadboard on the same end.
- Keep
- Waste, hatched on the drawing
- Dimension
- Long parts are broken. The 1 in bar is true scale.
Stock
Thickness steppers move by 1/16 in, or 0.5 mm. You can type 3/4 or 1-1/8.
- Do not put a rule joint on a breadboard end. Pick one language for the ends.
Sizes
| Mark | Size | Rule |
|---|---|---|
| Radius | 1/2 in | 1/2 in is the usual table-leaf radius |
| Leaf gap, closed | 0.032 in | About 0.032 in so the leaf does not bind |
| Hinge axis | on the centerline | The hinge pin sits on the joint centerline, not on the bottom face |
| Cove and thumbnail | 1/2 in | Cove on the leaf, thumbnail on the center, the same radius |
Cut sequence
1Plane the thumbnail and the cove
Radius 1/2 in. Cove on the leaf, thumbnail on the center.
2Set the hinge on the centerline
on the centerline. Leave about 0.032 in when the leaf is closed.
Stop when: The leaf swings and the faces meet without a ridge.
3Dry-fit, then glue
Close the joint dry. Check that shoulders and faces meet, then glue. If this is a frame or a box, check both diagonals before the glue grabs.
Stop when: Dry-fit is tight with hand pressure, square, and the diagonals match.
Glue
Mostly mechanical
Strength
furniture
Movement
The rule joint is a hinge detail. It is not a glue joint, and it is not a breadboard.